FAQs on Arowanas Systems Related Articles: Arowanas, Bony Tongue Fishes, Arowanas, Arapaima, African Butterflyfish, Featherback Knifes, Mormyrids, Elephantfishes,  Related FAQs:  Arowanas 1, Arowanas 2, & FAQs on: Arowanas Identification, Arowanas Behavior, Arowanas Compatibility, Arowanas Selection, Arowanas Feeding, Arowanas Disease, Arowanas Reproduction, & Bony Tongue Fishes, Aba Aba Knifefish, African Butterflyfish, Arapaimas, Featherfin Knives, Mormyrids, New World Knifefishes, My Arowana Tank (.com)

 

Freshwater Stingray / Arowana & big tank filtration related question.     3/15/16 Dear WWM crew, <Timur> there might be a bit of text, but bear with me. <Sure; take your time. Best to be thorough> I live in Czech Republic and I'm not new to the hobby, but not veteran either, though I do my fish stuff with passion. <Ahh!> I'm moving out this year and I had to sell my 120G tank, wood fishes & everything. (Still got 3 small tanks left, which will move with me, red cherry shrimps galaxy Rasbora etc) Here is my 120G when it was active. https://www.youtube.com/watch?v=1hWCI6nQoZ8 (https://www.youtube.com/watch?v=1hWCI6nQoZ8 )  Initially I wanted to go for Oscars, some silver dollars and bottom dwellers (like angel catfish), but after some weeks of thinking I will go for single silver Aro, school of silver dollars(Metynnis maculatus variant at least 8) and motoro ray or leopoldi ray (single) on the bottom (depends on the market). <The Arowana and either Potamotrygonid will grow... to be too large for a 120 gallon tank> I was thinking to go for smaller variant of FW ray, like reticulatus or hystrix, but after reading I learned, that they are not as hardy(not trying to say any FW ray is hardy here, all are very delicate) as motoro and that the tail gets very long + they are almost impossible to get in my country. <I see> I've studied the fish extensively and I'm aware of the diet, sand bottom and the size the fish will grow into. The diseases and issues that these fishes  have (like Drop-eye issue with silver Arowanas) and all the possible information .. dangers of the sting from the ray, treatment and possible long lasting effects. In the end this setup is what I came to.. the tank will be 330 gal/ 1215 liters ish including the filter which will be part of the AQ. <Oh! Yes> In ideal situation I would build bigger AQ and put 300liter sump filter below it. But I'm limited by the total weight of the aquarium & all the accessories. I decided on the fish setup (numbers) in regard to the bioload, surely some people would put more fish in it considering it's a big tank, but from what I studied this tank is a border-line minimum for an adult fish of the species and I would like it to have as much space there as possible for the fish, without having an empty tank. <Good; you and I's philosophy is concurrent here> Since I'm limited by weight (new house, but not meant for x tons of weight concentrated on one spot) .. I decided to put the filter inside (no piping outside the tank, no drilling) here's a diagram. Not here to discuss that, it's going to be inside. No canister filters either. <All right> On the diagram you can see that the swimming space for the fish is 200x90x60 which should be enough for these fish considering there will only be 1 Aro, 1 ray and school of smaller fish (15cm max silver dollars). I will have the water & drainage near the tank so water changes will not be an issue. <Good> Pumps will be either Jebao or something similar (intended flow from both pumps choked at 1000L/H each, because any more L/H and the overflow filter would not work properly and would not do the needed bio filtration correctly) adding bunch of Tunze Turbelle to create good flow in the tank. This image has been resized. Click this bar to view the full image. The original image is sized %1%2. I pretty much have a very good idea how the filter could look, here is another diagram, please comment on it. <Looks very work-able> This image has been resized. Click this bar to view the full image. The original image is sized %1%2. the first chamber is the intake from AQ and there will be a net so the fish wont get in.. now why is it so big you say, well because I want to add some sort of mechanical filtration in there. That's the only thing I'm unsure of how to do properly.. I thought of using the AquaEL turbo 2000 internal chamber filter to do that another diagram: <Open cell foams meant for aquarium use would be my first choice here... I'd have at least two sets; one for in-place use, the other for processing... bleaching possibly, freshwater rinse, air-drying...> This image has been resized. Click this bar to view the full image. The original image is sized %1%2. What do you guys think, or do you have a better solution for this first chamber ? I want to lessen the particles & waste that gets to the sponges area, I do know about the socks that marine aquarists use for their sump filters, but they clog way too fast and require change every few days according to the marine aquarists. <Agreed; these bags are better for marine applications> as for parts of the actual filter: starting from chamber to the left: blue is a sponge which will lessen the sounds that the overflow makes, below it is plastic that will hold it and allow good flow to the pumps (there will be 2 pumps hence 2 pipes inside of the chamber), pumps sit on sponge as to lessen noise. next mini chamber is 3 cm and is dedicated to create good flow, the 20 cm chamber is purely out of ceramic bio filtration media that will be in a netted bag, so I can easily take it out when needed. We get another small chamber for flow and then we have the sponges, I am not sure if it should be 20 ppi to 10 ppi left to right (coarse first) or just both of them 20 ppi, because there will be less waste coming. <Okay> The big question is how to do the first chamber properly. In ideal solution I would only clean the filter in first chamber i.e. - take out clean, put it back.. once in a few weeks. <The "blue" sponge material of pore size... I'd switch out weekly, when doing gravel vacuuming, water changes> And the actual bio media would not get cleaned in months.. all depends on how well the mechanical ones work.. Also what would you put inside of it? <More foam cut to size... smaller pore size> Picture related, the chambers are stackable.. up to the height of the tank basically.. I think 3 & 3 would be enough. No sponge there, just that plastic intake. Sorry for so much text, but it's easier to understand if I write this much <This is fine; am wanting to understand completely, and be understood in turn> Thank you for your time Cheers. <And you; Bob Fenner>

re: Freshwater Stingray / Arowana & big tank filtration related question.     3/16/16 Dear Mr. Fenner, <Mr. Tuktarov> thank you for your swift reply. I'm glad that you agree on the philosophy and that from your point of view the tank is sufficient for this fish setup. <Welcome> I had thought of keeping Jardinei instead of Silver Arowana, but from experience of many keepers of this fish, it is quite evident, that it is a gamble to try to keep it with anything like an expensive FW ray, so I scratched that idea. <This is best; they're not easily kept in "other fishes" set ups> "<Open cell foams meant for aquarium use would be my first choice here... > I'd have at least two sets; one for in-place use, the other for processing... bleaching possibly, freshwater rinse, air-drying...>" I see, what PPI would you suggest to use for these? <Not so important the porosity... as long as it is fit to the flow characteristics of the chambers, pump flow> I've re-made the filter design (8th now :D ) The initial filtration chamber what PPI would you use there? <The larger.... let me see if I can find on the Net: http://www.swisstropicals.com/filtration-shop/poret-foam-shop/ The Poret 30 PPI is a good choice> It's meant for mechanical filtration, I chose 15 cm instead of 10, so it would not clog so  fast, after this first chamber stops most of the dirt particles I put wool in second chamber right below the overflow, so the finer particles get caught there, wool would not be washed... just tossed when dirty. after that the second chamber could have a bit finer PPI (your suggestion?) <The 45> third chamber could use the same as the 2nd, fourth chamber would be sera Siporax or other quality ceramic rings for bio filtration, fifth chamber starts with foam, because the fifth chamber will have the least of water (pumps working) and there will be noise made upon water descending, that's why the foam is right below it. But the water has to flow fast here, so there will be 2 cm of free space so it can go over if needed. The green stuff is plastic tray meant to help with flow. Net is all over the "open" areas that connect to the aquarium, in the water and out of it, in case a fish decides to jump it wont get into the filter, net would be hard (non-corroding metal) and it would be "glued" with aquarium silicone. <A good plan> Since I've never built an actual overflow filter, I have to ask, will this work as intended ? <Should; yes> The pumps will be adjustable. Each can go from 600 to 2000 L/H and can be controlled by a remote .. so I can figure out the exact best flow. <Good> I expect to clean the first chamber once the flow stops going as fast as normally.. wool will be thrown out when needed. I think that at first (small fish) it wont need much cleaning.. but when they Aro/Ray grow to substantial size, it will require cleaning more often. <Yes> Goal is to make the chamber 1 and wool, the only things that need cleaning. Other chambers should remain clean for months ideally. Anything you would change here? Are the partitions in the filter correct? <Appear to be okay for starting> All of this is a theory by my I must say average understanding of water flow... <You're learning; and quickly. All will become much more clear w/ install and operation. Bob Fenner> re: Freshwater Stingray / Arowana & big tank filtration related question.     3/16/16 Dear Mr. Fenner, <Mr. T.> thank you for your time! Can't wait to build this. <Oh; please do send along progress reports, images of your work> Kind regards, Timur <And you; BobF> re: Freshwater Stingray / Arowana & big tank filtration related question.     3/16/16 Will do, expect them by the end of summer, my house should be finished by then. T <Ahh! B>

Water Softener, Arowana - 12/29/2012
thanks for your reply
<You're welcome.  Sabrina here tonight.>
i am using water  softener for domestic purpose,  is the water from water softener can we use for the aquarium .
<Preferably not, no.>
i am having silver Arowana the drawback from water softener is , it provides sodium chloride (saltywater),
<You are correct.  This is not optimal.  Although I do not know what your tapwater is like where you are in India, here (I am in the US) we typically have chlorine or chloramine added to the city water, and then people sometimes use water softeners for their houses for domestic purposes (like you are doing).  What we usually suggest to them is to use water from before it goes through the softener, and then to use a proper chlorine/chloramine neutralizer sold for aquarium use.>
whether salt water is good for silver Arowana , it will not be much salty.
<The biggest problem is that as you replace water that evaporates, you're going to be increasing the amount of salts in the water.  This is not ideal.>
give your suggestion
<If possible, use fresh tapwater, and use a chlorine or chloramine neutralizer, if these are added by your municipality. 
Best wishes to you,  -Sabrina>

Arowana  disease    12/17/12
i am  having silver Arowana,    it is having  only one  small  black  spot   on its  body ,   what is it ,  whether it is disease or  general body
scraping   . how to  over come  this , whether it is disease  means give some medicine name
<Please send some information about the size of the aquarium, how long the tank has been set up, filter used, any other fish in the aquarium. Read my
previous e-mail about maintenance of Arowanas, but note that Silver Arowana (Osteoglossum bicirrhosum) grow even larger than Asian Arowana (Scleropages
spp.) and consequently require even more space. They are prone to physical damage because they like to jump. If the scales are knocked off, then black patches can develop. Is the Arowana still actively swimming and feeding?
What are you feeding it? Cheers, Neale.>
about   silver Arowana, sys., using WWM    12/17/12
thanks  for your mail,
my Arowana  is  1.5  feet  long tank size  is   80 gallons , 350 l water   content filtration is canister 2200 l/hr  and  internal filter is 1500l/hr no  gravel in  the bottom  , tank bottom is  empty  only  my  doubt is  only  one  small black spot   is  seen near the body , give me your  suggestion  about this
<Please learn to/search WWM and use the indices... I'd have gravel in Arowana tanks... too much reflection otherwise; and added nitrification.
Bob Fenner>
silver  Arowana - wound    12/20/12
my Arowana  jumped  while i am  cleaning inside the tank,  by  got hit over the tank its scales removed  like  a   round shape, what to do  , any 
medicine for the scales to be cured. give some medicine  name for the  scales to   be healed
<Hello again, Harsara Ap! We have answered several questions from you -- but you have not given us ANY information about your aquarium, water quality, etc. Without this information we cannot help you. Cheers, Neale.> 
silver  Arowana - wound
my Arowana  jumped  while i am  cleaning inside the tank,  by  got hit over the tank its scales removed  like  a   round shape, what to do  , any medicine for the scales to be cured.
give some medicine  name for the  scales to   be healed
<This specimen needs to be in a larger system... a 1.5 foot Arowana won't live long, well in a 80 gal. volume. See WWM re this group... Stop writing and start reading. BobF>
wound
for what reason ur asking water quality.
for injury  i am  asking , why u need for water quality the  injury  is happened today, i am not talking about the past
What? Please send previous correspondence. Have no idea what you're
referring to; whom you were chatting w/ here. BobF
wound    12/20/12
for what reason ur asking water quality.
<Because injuries will not heal if water quality is bad. I assume you have a NITRITE test kit. Use it -- and be honest about the answer. Also, if the size of the aquarium is too small, the Arowana will simply injure again. It will not heal. This is why we need to know about your aquarium. How big is it? What is the filter that you use?>
for injury i am  asking , why u need for water quality.
<Because if the aquarium is wrong, the Arowana will die quickly. We need to establish that he is in the right aquarium.>
the  injury  is happened today, i am not talking about the past
<We also need to know how big is this Arowana; how long you have had it;
and what country you live in (not all medicines are available in all countries). Cheers, Neale.>
Arowana wound     12/22/12
thanks for ur reply,
<Welcome.>
i am from India ,  i am     not  having  much space in  my home , i have kept only  4feet aquarium  with 400 litres  of water ( 80 gallons).
<Much too small for Arowanas, whether Osteoglossum or Scleropages species.
A young specimen (up to about 20 cm/8 inches) could work, but you would have to work extremely hard keeping the water clean. Zero ammonia and nitrite essential!>
filtration is canister 2200l/hr and internal filter  1500l/hr. while  i am cleaning, Arowana got wound  , its  scales  fallen from the body  like a round shape. give some remedy   or  it will normally  the wound be cleared
<In good conditions, missing scales will grow back. I would also treat with antibiotic of some sort; Erythromycin and Minocycline used together would be ideal. But long term, this fish needs a bigger home. In a small tank Arowanas are prone to jumping (hurting themselves) and also problems such as "Gill Curl". Cheers, Neale.>
About  water quality   12/22/12
You have stated ammonia and nitrates should be zero in  the tank.
<Hi, in the future we request that you use proper spelling and grammar in your queries, this makes it easier for other readers to use and allows search engines to more accurately find relevant information.  As to your question, ammonia and Nitrite should be zero, nitrate should be low, less than 20 ppm.
How to keep it stable , shall we  add  Zeolite  to the canister filter.
<This is controlled mostly through bacterial processes and proper maintenance and feeding.>
How to keep  nitrates to zero
<Nitrate is best controlled through regular water changes.>
awaiting for ur reply
<Chris>
Re: Another Arowana-in-80-gallons question     12/24/12
thanks for ur reply,  my question is  when powerhead in the bottom of the tank, due to  heavy pressure  it is not giving air bubbles, can  we  connect  additional separate  air pump   to the venturi  valve  nozzle in the powerhead?
<Powerheads won't work more than a few cm below the waterline. In deep tanks, install an airstone driven by a very powerful air pump. But you should not be relying on air pumps for making water "better". Circulation is better provided with powerheads, and if your water doesn't have enough oxygen in it for your fish, then get a bigger aquarium! You cannot keep Silver Arowanas in less the 200 gallons.>
i want air bubbles because  it   looks  beauty , connection between powerhead and separate  air pump means there will  be  wrong  gas  exchange will happen. awaiting for ur reply
<Hmm… do spend more time reading, and less time writing! Can I recommend the following:
http://www.wetwebmedia.com/fwsubwebindex/osteoglossiforms.htm
http://www.wetwebmedia.com/fwsubwebindex/arowanafaqs.htm
http://www.wetwebmedia.com/fwsubwebindex/ArowanaSysF.htm
http://www.wetwebmedia.com/fwsubwebindex/ArowanaDisF.htm
Most problems with Arowanas are caused by their environment; get that right, and these fish are hardy and interesting. But they need HUGE aquaria with MASSIVE filters to do well. Cheers, Neale.>
air pump  connection with  powerhead, Arowana sys.     12/25/12
why we  should not connect  air pump  to the  venturi valve nozzle of the powerhead,
<You can.>
i  don't want to give separate  airstone diffuser by  air pump i want to give air circulation by  means of powerhead with air pump. give your suggestion
<Adding more air won't make an 80-gallon aquarium any better for an Arowana. Please do understand this. Merry Christmas, Neale.>

about UV  filter 12/16/12
i am  having canister filter  and  internal   filter for my Arowana tank ,  but my tank  always  seems to be cloudy only.
<How big is this aquarium? How long as the tank been running for? Let's recap the reasons for cloudy water:
(1) Silt can come from new gravel and sand. Silt settles out over a few days, and you can see it sticking to the substrate, plants, etc. To remove silt, stir the gravel or sand, remove 25-50% of the water, and do this as often as required until the water is clear. Remember, of course, to make sure any new water has the same water chemistry and temperature as the water that was removed.
(2) Algal blooms, particularly diatoms, can make the water seem cloudy.
Unlike silt, which settles out over a few days, algae remains in the water column. It also tends to have a golden hue that silt lacks. Algae blooms normally go away by themselves within 3 months of setting up a new aquarium. Sometimes they come and go, each bloom lasting a week or two. UV filtration can help a great deal. Algal blooms are not common in mature, established tanks but may happen if there is direct sunlight on the aquarium.
(3) Bacterial blooms may also occur in new tanks less than 3 months old.
They are more white than golden, and tend to go away very quickly if water quality is good. If bacterial blooms last more than a week, then there is probably a problem with water quality. Usually it means biological filtration hasn't become properly established. It can also mean the aquarium is overstocked and/or under-filtered. Review, and act accordingly.
(4) Finally, the aquarium may simply be dirty. Too many fish, too much fish faeces and uneaten food, and not enough filtration and/or the filter isn't maintained properly will mean solid waste particles build up in the water.
Again, review and act accordingly.>
how  to overcome this cloudy water, I am often water changing and maintaining the tank.
<Indeed? Let's review what an Arowana requires. Assuming one of the "small" Asian species (Scleropages spp.) then you have a fish that will grow to around 60-90 cm/2-3 ft. An adult will need an aquarium NO SMALLER than 750 litres/200 US gallons. Even a youngster around the 30 cm/12 inch mark should have an aquarium no smaller than 375 litres/100 US gallons -- and honestly, you'd be extremely unwise starting an Arowana in such a small aquarium. Filtration needs to be massive; aim for a turnover rate not less the 6 times the volume of the tank per hour, i.e., 4500 litres/hour (1200 gallons/hour) for an adult specimen. Almost certainly that will mean multiple canister filters -- a "big" Eheim 2217 for example "only" offers 1000 litres/hour -- and most serious Arowana keepers opt for marine-style filters using overflows, big pumps, and some type of mixed filtration system (like a wet/dry filter) underneath the tank in a sump.>
shall I place UV filtration  to overcome cloudy  water,
<UV filtration will ONLY fix algal blooms; for all other situations, you need to review the aquarium and make necessary changes.>
give me your suggestion
<My guess here is that the aquarium is too small and under-filtered. Review my comments above, and compare to what you are doing; do buy or read online information on the maintenance of Arowana species -- there is much good knowledge about these big, difficult-to-keep fish. Do be aware they are extremely expensive to maintain, need excellent water quality at all times, and quickly die if not kept correctly. Cheers, Neale.>

Many questions concerning Cycling, Floating Plants, Acclimating Fish, etc, Arowana sys.,  FW   3/28/10
Hello WWM crew -
<Hi Raymond! Melinda with you here tonight!>
I have spent many an hour browsing through your articles online, and before I start asking questions I would just like to thank you for all the effort you guys have put into compiling such a large amount of content about so many different subjects related to fishkeeping. Keep up the good work!
<You're certainly welcome, and also thanks from the crew and me!>
Now, onto my (numerous) questions:
- The water that I have at my house is naturally at a pH of 6.0. I like to keep my pH at around 7.0 as it seems to be a good all around pH that many different fish can adapt to. Is using baking soda to raise the pH of the water a good idea? Will it help the buffering capacity of the water as well?
<Yep. In fact, there's a great mix that will do this exact job... I also have very, very soft water, and I treat about 1600 gallons of freshwater with it... different tanks, as well as an indoor pond... all are at a steady 7.2, with a KH of 4! How's that for consistency? Here's a link to the article which not only helped me understand the relationship between KH and pH, but fixed my soft water woes for good:
http://www.wetwebmedia.com/FWsubwebindex/fwh2oquality.htm
I cannot recommend this mix enough. It makes my life so easy, and it's a cheap mix to make, and easy to measure, and... well, you'll see.>
- Since the water that I get is well water, I never really thought that I needed to let it sit (no chlorine type stuff in there). However, it does pass through fairly old copper piping. Is that something that I have to worry about, since some of the fish I plan on getting are sensitive to copper (i.e. Clown Knife)? In order to ameliorate this possible problem, is letting the water sit for a few days enough or do I have to do more?
<Your local fish store should sell a test for copper, or may even have a test on hand to run for you if you'll bring in a water sample. This would answer the question as to whether copper is present and at what amount.
Copper doesn't evaporate, as chlorine does, so letting it sit won't help.
Poly-Filter will remove copper, though, if you've got a really high concentration of copper in your tap water (yet to be determined!), I'd really look at the costs of purchasing an RO/DI system versus purchasing Poly-Filter in the long run. It could end up being a better deal, especially for a large tank. It all starts with determining if copper is present, though.>
- Does having plants in your aquarium at the start of the cycling process make it faster? If so, at what stage should the plants be added in (I'm mainly interested in the hardier, floating varieties of plants here, such as water sprites, liverwort, etc)?
<Plants will absorb some ammonia, but I wouldn't expect them to do the job completely, especially if they're just settling into the system and not growing as well as they would once established. You can add plants at any time, but I would cycle the tank using the fishless cycling method, and just use your test kits to determine when you're ready to add fish.>
- During the cycling process, should I change the water in the tank at all?
And if I clean the clean the gravel of my already established 55 gallon tropical tank and dump the "gunk" into the new tank the cycling will be much faster correct?
<You can do water changes during cycling, but if you use the fishless cycling method, you won't have to. This is really a better method overall.
I can't tell you (but you have no doubt seen, with even a quick perusal of the site) what problems come when folks try to cycle with fish. As for the "gunk," it does contain beneficial bacteria; however, I am much more in favor of using cycled, or seeded, filter media instead -- more water flow through the media is beneficial. Please read here on cycling:
http://www.wetwebmedia.com/FWsubwebindex/fwestcycling.htm>
- Would it be better to start a small (4-6 inches) Silver (or Jardinei) Arowana and a Clown Knife in a smaller tank and then move them to their larger tank as they grow or just have them start in the larger tank? I was mainly worried about the ease of feeding, although a smaller tank could be subject to wider swings in water chemistry.
<What is the "larger tank?" These fish all grow very, very large (three to four feet for the Silver Arowana and the Clown Knife), and though the Jardinei grows to a smaller size (Two feet or so), it can quickly make life hell for other tank inhabitants. Jardinei aren't at the top of the list for Miss (or Mr.) Congeniality... please read here:
http://www.wetwebmedia.com/FWSubWebIndex/osteoglossiforms.htm
I would hope a tank for any of these fish would range in the four-hundred gallon size, with beefy filtration... a big task, indeed. I in no way mean to offend, but only to make you aware, if you are not already, of what you're getting into with these fish. If you properly establish the "smaller" tank, and use the mix mentioned above to keep pH and KH steady and elevated, then chemistry swings will not be an issue.>
- Would the floating plants liverwort, water lettuce, Amazon Frogbit, or water sprites serve as adequate cover for Arowanas and Clown Knife's to help prevent them from jumping? How would the floating plants get along with a HOB filter?
<Arowanas will jump, no matter what is on the water's surface. Clown Knifes aren't as big of a worry with jumping, and would do fine with your standard glass tops. But, please do take my word here: many Arowana owners have lost their three-feet long beauties to jumping, and sturdy, sturdy covers is all that will keep them in the tank. Think big, and heavy. More than a glass top. As for an HOB filter, honestly, I'm not sure what place it has here. You're talking about fish who need a turnover of eight to ten times per hour, which, with the necessary tank size, is one heck of an HOB filter. Filtration for these fish is often accomplished with huge wet-dry systems, a ridiculous number of large canister filters, or some DIY concoction. I keep large fish (3 Pacu and a S.A. Red Tailed Catfish, to be exact!), and I find it incredibly enjoyable, so please do not think I'm trying to discourage you. It just sounds as if you may not have completely thought this one out! As for the plants with an HOB, I've tried this one.
I found it annoying that the plants were constantly being "sunken" by the output of the HOB... they float back up, but it looks kind of funny. And they're sucked over to where it is, due to the suction from the intake, so it's kind of hard to keep them where you want them!>
- In terms of acclimating fish, I read somewhere that it is less stressful for fish to adapt to a change in temp and pH than sitting in a bag full of their ammonia / fish waste. This thing I read essentially advocated dumping the bag onto a strainer of some sort and then dumping the fish into tank water (not necessarily the tank), and then moving the fish into the tank.
Would this be better than the drip method? Does this have any merit to it?
<No. It would certainly stress them more. The drip method, or some version thereof, would be better here.>
- Finally (!), a general question about fish eating other fish. I know not to feed "feeders" bought from a pet store, and I saw that you advocated not feeding things like baby convicts (amongst other foods, such as krill) to fish for fear of the spines penetrating their stomachs. If this is the case, how do fish that eat other fish in the wild survive? Just a curious question.
<Fish in the wild enjoy a variety unmatched by what aquarists can, or do, provide. Often, the fish fed to predatory fish in captivity are coming from the most readily-available source, such as the pet store, which carries, probably, minnows and goldfish. Therefore, there's no variety being provided. It is the equivalent of a human eating steak for every single meal -- that could, obviously, become an issue. It's the concentration of thiaminase provided to most predatory fish that becomes an issue -- that it's present in every single meal. I have several predatory fish, only one of which refuses prepared foods. I cannot stress the size difference in the two Florida Gars which consume pellets, fish filets, squid pieces, and other tasty delicacies to the fish which will only accept feeder fish. They are fifty percent longer than him, and twice as big around, though they all started at the same size! There is no doubt that variety is the key to fish health when it comes to feeding, which is why fish do so well in the wild, and why aquarium fish, when fed properly, do much better than those that aren't. My advice is always that if your fish will eat other foods, don't feed it feeder fish. It's just better for everyone. For instance, have you even thought about how much effort, space, electricity it takes to quarantine enough feeders for a four-foot Arowana? Argh.>
Thanks for taking the time to read all my questions, and keep up the great work!
<I've tried to be thorough here, because I absolutely don't want to scare you off from keeping big fish. I just want you to know what you're getting into! Please write back if you have any more questions after reading.>
Sincerely,
Raymond
<--Melinda>
Re: Many questions concerning Cycling, Floating Plants, Acclimating Fish, etc. Arowana sys.,  -- 3/31/10
Hi Melinda (or whoever ends up responding to this email) -
<Hi, Raymond!>
Before I begin, thanks for your very quick reply. I am also very envious of your indoor pond .... someday, when I win the lottery perhaps!
<Can be done cheaply... or I couldn't have done it!>
First off - yes, I am aware of how large Arowanas can get (and their jumping predilection).
<Oh, good.>
The larger tank is a standard 300 gallon aquarium (a little narrow, but...).
<Yes, this is where I would look into a possible pond... You could build something very sturdy for the price of a 300 gallon aquarium, especially if you're going with the whole kit-n-caboodle... stand, canopy, and all can get quite expensive. This would allow you to really take liberties with some heavy-duty DIY filtration, which you could design to work with your pond design. There are message boards, sites online for folks who keep big fish, and there are a lot of ideas out there for ponds. This would allow you to control the shape, making it plenty wide for your fish.>
In fact, I lost a 2-foot silver after he barged through my weighted-down glass covers! Never again will I underestimate their jumping ability.
<I'm sorry to hear this... as I said earlier, this is all-too-common. At least you're not only not giving up, but using acquired knowledge to improve, right?>
Any suggestions on how best to secure the lids? That being said, I thought having plants on the surface would calm the Arowana down a bit, encourage the Arowana not to jump (similar to lowering the water level somewhat), and at worst serve as a sort of cushion if one does jump into the lids.
<Ah, yes. Knowing more about your experience and your potential set-up makes me feel a little better about answering here, "Yes. They would be helpful." Haha! Floating plants plus sturdy cover is better than what I was thinking before, which is that you hoped to rule out jumping just with the plants. They can also help with giving him some shade from the bright lighting we typically use in aquariums, what with Arowanas being top-dwellers... could be a little bright for him. As for securing lids,
I've honestly seen everything from tie-down straps (like you use in moving) holding lids on, which isn't very pretty, to homemade heavy wood lids coated in a waterproof epoxy or some other protective coating, complete with an epoxy-coated frame around the top of the tank to tank to secure or latch the lids to, which can look quite nice. There's just not much out there, to my knowledge, that's sold pre-made and will keep these fish where they belong!>
I also realize that jardinei's are potentially very nasty fish. If I chose to go the jardinei route I would keep it by itself.
<Is really the only way. It's sort of a Catch-22, because, compared to the Silver Arowana, the Jardinei is a little easier to accommodate at its adult size, but its presence often rules out any other tankmates. For the 300 gallon you mention above, I think a Jardinei would be a better option, seeing as how you'd probably end up keeping the Silver Aro solo, or at least with very few tankmates, due to the bioload his presence will have on the system, anyway.>
Regarding the filtering question - the HOB's would not be, and were not, the only filters - I was merely under the impression that they provided pretty good biological filtration.
<Well, for biological filtration, you can't beat a canister filter filled with biological media, simply due to how much media (surface area for bacteria growth) it offers. I would skip HOBs here altogether, and even if you do end up with a DIY filter or a wet/dry, I'd still use a canister as redundant biological filtration.>
I have been looking at setting up a wet/dry filtration system, as I am tired of dealing with canisters. Are they less labor intensive than
canisters?
<I have not found my canisters to be labor-intensive at all! In fact, I don't mess with them much, and I buy the filter pads in big sheets and cut them to fit what canister I want them to go into, so they're fairly cheap to maintain. I've run a wet/dry on a freshwater tank once, before my catfish moved to his pond. I found it fairly easy, but you do have to remember that we don't have the ability to eliminate Nitrate in freshwater systems that marine aquariums benefit from. So, extra attention has to be paid to ensuring there's not a lot of excess waste on the bottom of the
wet/dry, and that, if bio-balls are used, they're not trapping a lot of waste and allowing Nitrate to build up. I found this to be an issue simply because the big, bulky sump wasn't as easy to move around as the canisters, which sort of made it more of a pain to clean. Obviously, though, you can make a sump as large as you want it to be, and choose pump sizes to meet your filtration goals, so that sort of indispensable in your situation! I guess there are pros and cons to both types of filters, but when you're looking for the turnover you're going to need for this fish, a combination of both would be a good way to go. Plans are readily available online for DIY wet/dry filters, so that could save you some cash in start-up costs, rather than purchasing new, if you are so inclined. Have you ever used the discussion board here on WetWeb? It would be a good place to start and possibly get some ideas, and a good old google search would probably turn up more than you ever wanted to know about constructing/keeping systems for these fish. Please do write back if you have any questions!>
Thanks,
Raymond
<--Melinda>

Arowana Tank size  11/26/09
Hi Neale
<Hello again,>
I have silver Arowana of 7inches.
<Okay.>
Presently it is in 30inches X 15 inches X 18inches (height).
I am getting a new aquarium made for this silver Aro future purpose.
<Excellent!>
I have a chance for 8ft in length. What are the advised dimensions?
<Wow, that'll be a perfect tank. Plenty of space for a catfish and an Oscar, if you wanted them. Okay, in terms of size, the ideal would be 8 foot long by 3 foot broad. You see, the aim is to keep the fish in a tank as broad (from front to back) as the fish is long. Since this species gets to about 3 feet in length in captivity, that's the minimum breadth. Depth doesn't matter too much, since the Arowana stays at the top. But a 3 foot depth would be good. Realistically, a 6 x 2 x 2 foot aquarium is too small for Silver Arowana, while an 8 x 3 x 3 aquarium would be excellent.
Anything in between would be okay, provided the breadth was closer to 3 feet than 2 feet. Make sense?>
Secondly what all I can keep inside for decoration such as which type of live plants?
<I'd recommend floating plants since these stop the fish jumping. Good plants for the middle of the tank would be plants attached to bogwood, for example Anubias and Java fern. Since these fish are messy, it helps that these plants can be moved about when you are cleaning the tank. You can even remove them from the aquarium without causing them harm, so that thoroughly cleaning the tank is easy. They don't need any gravel at all, leaving more space for water. If you did have a couple of inches of gravel, you could plant some Vallisneria along the edges of the tank. These help prevent the fish bumping into the glass.>
what type of gravel is advised?
<If you go with just floating plants and plants attached to bogwood, you need very little gravel. Plain gravel to a depth of 1 cm or so will be fine. Doesn't matter what kind you use, so long as it [a] isn't brightly coloured and [b] is lime-free (so it doesn't raise the pH).>
what type of other articles which can be kept inside which does not disturb the Aro?
<Best not to add anything that fills the top half of the water column.
Arowana want swimming space! A few pieces of bogwood on the bottom look nice, and will provide a home for a suitable catfish such as Panaque nigrolineatus. But otherwise, don't worry about decoration.>
Thank you in advance.
Asha
<Happy to help. Cheers, Neale.>
Re: Arowana Tank size   11/26/09
Dear Neale,
Thank you very much for the reply.
<My pleasure.>
But...but...with reply you added one doubt in my mind. You spelt out names of catfish and Oscars? Do you mean I can keep them along with Arowana?
<Yes. They get along well with Osteoglossum species.>
Or do you mean to say keep only catfish and Oscars in such a big tank?
<No. You could keep your Arowana, an Oscar, and a Panaque catfish in the same big aquarium.>
Asha
<Cheers, Neale.>

Please Advice... Arowana sys., fdg.   11/21/09
Dear Sir,
<Hello,>
I have 7 inches Silver Arowana. When I got it , it was of 6 inches only. It is about one month with me.
<Still very much a baby.>
The aquarium size is 2.5 ft X 1 ft X 1.5 ft (height).
<Much too small.>
I have another aquarium of 42 inch X 18 inch X 24 inch (height) ready to shift this Arowana when it grows.
<Good. But even this tank is marginal. Silver Arowana get to around 90 cm (~3 feet) long, and it's hard to keep them in anything less than tanks 2 metres (about 6 feet) in length.>
I have been feeding him with guppies and Mollies. Can I continue this or not?
<I would not be feeding them live fish at all. Are you breeding these Mollies at home, or do you buy them from a pet shop? If you breed your own feeders, that's relatively safe. But buying cheap fish from a pet shop is very unwise. Since Arowanas eat all sorts of foods, including pellets, it is safer and more nutritious to use these. Crickets, mealworms, earthworms and river shrimps make safe live foods. Wet-frozen foods like lancefish, prawns and mussels are good. Companies like Sera make Arowana pellet foods.
I wouldn't use them all the time because dried foods tend to cause constipation, but for about 50% of their diet, such pellets would be ideal.>
I have not added any salt to the water.
<Good.>
It is doing very good.
<Nice to know.>
Do I need to add salt to the water?
<No.>
Murali
<Cheers, Neale.>
Re: Please Advice. Silver Arowana sys., fdg.   11/21/09
Dear Mr. Neale,
<It's just Neale. Or Dr. Monks. But between friends, let's just stick with Neale!>
Thanks a lot for your inline reply.
<Happy to help.>
I will shift to the feed as advised by you.
<Great.>
But when I got it, I tried to give the feed of shrimps, pallets, dried warms ...But it was not taking them.
<Often happens.>
They were lying till next day morning. Then I tried with Mollies and guppies for which it was happy and eating. How can I migrate the baby Arowana to the advised diet?
<Since he's eating these foods, "wean" him off them. This means one day next week, offer him something else, maybe some crickets or an earthworm.
Insects are the natural food of Arowana in the wild, and a perfect food for them. If he doesn't take them, remove the uneaten food within a few minutes -- and let him starve that day. Try again the next day. It may take 2-3 days before he eats new foods -- but he will! Big fish can go two weeks without food, so this isn't dangerous. Anyway, once you have him taking other live foods (like mealworms, crickets and earthworms) try him with frozen foods. A small piece of prawn or white fish fillet is ideal. Use long forceps or a wooden satay stick to hold the food. Wiggle the food to make it look alive. Hopefully, he will come and bite the food. The idea is to teach him to eat anything you offer. Eventually, predatory fish will eat all sorts of foods, because they learn anything you give them is tasty and nutritious! Once that happens, your Arowana will take pellet foods.>
Please advice me.
In an year how long the Arowana will grow?
<The usual estimate is one inch per month for the first year (in metric,
that's about 2.5 cm per month). So you can expect a Silver Arowana to be at least 12 inches/30 cm after the first year. In good conditions, they can grow faster than this. So take this as the MINIMUM.>
So that I can prepare for the advised size of aquarium.
<Plan ahead! 200 gallons/750 litres is often quoted as the minimum tank size for this species, but honestly, they probably need more than this to do well.>
Thanks in advance Mr. Neale.
<You are most welcome.>
Murali
<Cheers, Neale.>
Re: Please Advice, Arowana fdg., Oscar sys.  -- 12/08/09
Dear Neale,
Good Morning.
<Hello again,>
Now my Arowana is eating the food that I provide except for shrimp food of Taiyo company. Some how it did not like this particular brand's food.
<Give it time. "Hunger makes the best sauce" is an expression we say in England; if you skip a meal or two, your Arowana will eat this food!>
Well. Goo news is that my 6ftX3ftX3ft is getting ready. I want to keep my silver Aro along with 2 copper and 2 tiger Oscars in that. They are all together in the present small aquarium. I plan to shift them on 11th of this month.
<OK.>
Please advice me on the following things.
1. What type of stones/gravel should I fill in the bottom?
<Minimal. The Oscars dig, and the Arowana doesn't care. So use a thin layer (2 cm maybe) just to cover the glass and stop reflections. I'd go with smooth gravel of some sort.>
2. What type of filtration system is advised.
<Certainly some type of heavy duty canister filter will be required. Given how sensitive Arowanas are, and how messy Oscars are, don't take chances here! I'd go with at least two big canister filters, so if one breaks down
or needs servicing, the other will still be running. The Fluval FX5 (900 gallons/hour) is a good budget option for really big tanks, and has had quite good reviews. You might also consider using a small pond filter instead. Aim for at least 6, and ideally 8-10, times the volume of the tank in turnover per hour. Your tank is about 400 US gallons, so aim for 2,400 gallons/hour, minimum.>
3. How much lighting will be advised. Either in luminous or size of the tube light.
<Couldn't matter less. If you want some floating plants and Java ferns to decorate the tank, then you'll need at least 2 watts/gallon given the depth of this tank. If you don't plan on using live plants, then use whatever lights you think make the fish look pretty. Gro-Lux tubes are nice.>
4. What kind of internal decorative advised?
<Minimal. The Arowana needs open swimming space. The Oscars will need a few caves; terracotta flower pots and similar such things work great.>
Thank you in advance.
Murali
<Cheers, Neale.> 

Future Housing for Arowana, Clown Knife, Bichir 05/23/08 Hi WWM Crew, <Ray> Before anything, I just want to compliment you guys on the great job you guys do. I've spent many an hour browsing through all the articles on your website and I've found it very helpful to my own fish keeping experiences. In any case, let's get on to the question! <Okay!> I currently have a 135 gallon tank with a ~18 inch silver Arowana, ~8 inch pike cichlid and about a foot long Bichir in it (not sure what species though - definitely not ornate and not Senegal Bichir though). I also have a 125 gallon tank with a foot long clown knife in there with a 6 inch sun catfish and 2 ~3 inch sun cats. I know that I have to upgrade to keep these beautiful fish for life. My question is three fold. First, can a tank measuring 8 ft long by 2 ft wide by 30.5 inches high (that's around 300 gallons) hold all these fish for life, or if not, for quite a while? <Yes... likely so... the Arowana... if it doesn't "jump out"... the rest for sure> Secondly, can the pike cichlid coexist with the clown knife? <Yes... unless the Notopterid gets much larger, faster... and consumes the Cichlid> It's already fairly territorial, though it doesn't seem to bother the Arowana or Bichir too much. I'm worried about mixing the pike with the clown knife though. <Oh! It very likely will know/knows to leave the Knife be> Finally, before my Arowana downed thawed, previously frozen shrimp like none other, oftentimes eating 4 or so with no problem. However, ever since I've come back from college, he refuses to eat any shrimp at all, and totally ignores them. The Bichir still eats them so it's not a problem if they fall. My parents assured me that while I was away the only thing they fed him were newts and earthworms, as well as floating cichlid pellets, that were caught from my yard (we don't use any pesticides / fertilizers at all). Do you have any idea why this is so? <Mmm, why your parents fed what they did? Or the Arowanas new preference? The last likely from practice, distinction> Thanks in advance, <Bob Fenner>

Arowana and Silver dollars in a big planted tank, sys.  2/29/08 Hi, I have a question that has many different angles to be looked at. I have been reading your website for the past 2 or 3 years and have scoured about 50% of the freshwater info as I have found it invaluable. First off, I have a pretty big L shaped aquarium, 8 ft long, 45 degree angle of 4 feet, then another 45 degree angle of 8 feet with the tank being 2 feet deep and 2.5 feet tall acrylic tank (about 900 gallons +/- 50 from evaporation etc.). Ammonia and nitrites are of course zero, nitrates are between 20 and 40ppm (attributed to nitrate factory type trickle Bioball sump), pH at a steady 6.8 attributed to the large pieces of driftwood I have in their and their tannin releasing ways, hardness is at 80ppm. Temperature ranges from 74 to 76F in the mid to upper levels, 72-75F in the lower levels, due to lighting I guess. Filtration turns the tank over about 5-6 times an hour, though with cloggy filters, maybe only 3 times an hour. <Does sound like you need to upgrade the filtration a bit; in all honesty jumbo fish need all the turnover you can get. I'd be looking at 6x turnover minimum, and likely 8-10. If water quality is basically sound, you can perhaps get away with just adding a powerhead or two into the tank to keep the circulation of the water even.> It currently houses a foot long silver Arowana and a school of 11 silver dollars (the smaller 5-6" ones, not the red hooks). I also have 4 fairly young (only 1 foot tall, about 20 leaves) Amazon swords planted in 2 inches of gravel, and a whole bunch of Anacharis that's growing like a weed (for the silver dollars munching pleasures) though it is growing much faster than the fish are eating them. <Sounds great!> I also have some powerful full spectrum lighting across the two 8 foot lengths of the tank, nothing in the middle of the L. My more concerning question, or more likely, situation, is that my Arowana (I've had it since it was around 5") recently started taking dives at my silver dollars as they swim on their merry way beneath him. Is this a show of territoriality or is he trying to eat the silver dollars or both? <Either. Both. Arowanas are territorial and object to anything in "their" zone of operations. This varies with species, and Silver Arowanas are very much at the mild end compared with, say, Scleropages jardinei. But on the other hand that doesn't make them friendly community fish! If the Arowana is sufficiently big, it may be trying to eat them, or at least "sample" them to see if they're edible. A 6" Silver Dollar is borderline when it comes to safety with an adult Arowana. Some people have mixed them fine, I know; but look at how big the mouth of an Arowana can get! I wouldn't be 100% comfortable with this combo.> The silver dollars are way faster than him though so I have not yet scene what happens when he catches them. He is usually just silently sitting beneath a carpet of Anacharis during the day and only moves when fed (Hikari Arowana pellets plus weekly beef heart, plus whatever flakes, crumbles, bloodworms I feed the silver dollars) or when the lights are off. Also, I read that Arowanas generally leisurely patrol the aquarium all day and I figured now that I finally built my uber aquarium (oh that's right, self made... 20% of the retailers price... plus several cases of beer and pizza for friends who assisted in heavy lifting. <Ha!> Is it possible that my lights are too bright and the Arowana doesn't feel safe or its hurting his eyes, though he did just swim around normally for about a month until he started to "hide"? They are power compact fluorescents, 525 watts per light fixture, 4 total fixtures. This is a major concern to me as I have been keeping fish for the better part of a decade wanting an Arowana but refusing to get one until I could house it properly and now he just sits there. At night I have moonlighting and he does then move around quite a bit, this is why I suspect the lighting, but I never thought they were nocturnal... more diurnal from what I read. <Difficult to say on this one. Arowanas are noted for being photophobic, though most fish prefer shade to bright light. Do all the lights come on at the same time? Sometimes fish get alarmed by that, and having the lights come on across an hour makes a big difference. It does sound like he doesn't like the light. Is adding an understory of plastic plants (there are some great 3' plastic plants available now) an option? Something that could drape across the surface and cast some more shade? I suppose the experiment would be to unplug one light fixture for a day or two, and see if the Arowana prefers that end of the tank.> My next question has to do with the silver dollars and them seeming to enjoy eating the Amazon swords more so than the Anacharis. Is there some other large show plant that does well under high lighting that the silver dollars wont want to eat? <I'd perhaps look at Crinum spp., e.g., C. calamistratum, as these do seem to be left alone by herbivores. They're big and generally hardy. Java fern will do great under bright light, though it does tend to become an algae magnet. Anubias even more so.> Also, my swords aren't exactly growing as well as they had in past tanks with 4-5 inches of gravel. Does the gravel depth make that much of a difference? <Yes; also the quality/composition of the substrate.> I have something like a thousand Malaysian trumpet snails aerating the gravel and what not but am concerned that if I add more, the snails just wont be able to irrigate and aerate all that gravel, and the last thing I want is some anaerobic environment unreachable by plant roots or snail burrowing releasing poisonous hydrogen sulfide and the likes into my tank, plus stinking up my fish room. <Just doesn't happen. The "anaerobic decay" thing is largely a myth. Happens naturally in ponds and in marine tanks (inside living rock) and no-one fusses. So by all means ramp up the depth of substrate to what worked before. Do also check first that the substrate is adequate though -- Amazon swords want a nice rich soil or laterite enriched substrate, and plain washed gravel just won't work for them.> Should I consider ditching the silver dollars for a school of tinfoil barbs? They don't eat plants at all do they? <Tinfoil Barbs can, will eat plants.> And lastly, as you may have guessed it, I want to add more fish to this tank as it seems fairly empty... I'm thinking black ghost knife? <In theory fine, but you'll be hard pressed finding an adult large enough for this community. Mostly you only see baby Apteronotus for sale.> I first filled up the tank about 8 months ago, filling it with something like 100 Malaysian trumpet snails and about 20 mystery snails for my tank cycling. I over fed the snails for 3 months in order to obtain the current population explosion of snails I now have, <Consider adding a group of Clown Loaches or thorny catfishes (Doradidae). These will eat the snails, if sufficiently hungry.> at the end of month one I added the sword plants, then I added the silver dollars at the end of month 3, all at about the size of, well, silver dollars. They mostly hid in the center decor castles of my tank for the first two weeks but then began to sprint (if you will) from one end of the tank to the center and back (they seemed to never travel into the leftward portion). After having them in there for 2 months, they had grown to about 3" in diameter each and I added my Arowana at 5". After only another 3 months the Arowana (from what I could tell) doubled in size, which I attributed to it having so much space to swim. <Or simply good maintenance. Arowanas grow quickly if kept well.> Now I added the Anacharis about 2 weeks after the Arowana was added and it was generally ignored by all but a couple of snails. Then a month ago (beginning of month 7) is when the Arowana began to just sit under the Anacharis. So yeah, back to the black ghost knife... I want to buy two of these guys (I figure the tanks big enough) and I put two PVC condos with 15 pipes of 2" diameter and 1' length in there, one in each 8' portion. Should I be concerned about the Arowana eating them as I often find the knife fish around 4-5 inches in length max, and it will be some time before they grow to their 2' potential where the Arowana wont (hopefully) eat them. Are the black ghosts fast enough to evade the Arowana if pursued? <No; sooner or later, if they're small enough to swallow, they'll be eaten. The Arowana only has to get lucky once!> And for the record, despite clown knives growing huge and not being swallowable by my Arowana, they will probably eat my silver dollars and knock over my plants, and just grow too big for my taste, so that options out. <I agree.> Well, that's all for now. I literally read all over the web for months and abstained from just writing you guys since I know how annoying it can be to be asked simple questions that have their answers everywhere... but I just cannot find anything like this Arowana diving at silver dollars thing while not swimming anywhere else. I am a student of the sciences, my job being that of a biochemist, therefore I was cocky, stubborn, and reluctant to ask for help (a character flaw repeatedly pointed out by many over the years)... but there are just some things you cannot learn in books. I'll likely have another question or comment in a couple of months after the knife fish are added... if they are compatible. Thanks in advance for any advice you can provide. With Best Regards, Matt <Hope this helps, Neale.> Re: Arowana and Silver dollars in a big planted tank (RMF, please comment)  2/29/08 Well It looks like I'm going to be upgrading my sump pumps using some pond pumps to get that water flowing up to the 10 times over level. I currently have four overflow filters going into four 55 gallon tanks... I guess I will just have 4 extra pumps to sell on aquabid.com as I replace them with the pond pumps. The pumps I have looked at are reporting 1800 gallons an hour (Danner Supreme Mag Drive Aquatic pumps, I currently own the 1200 gph pumps)... am I going to need larger sumps or will this push through the 55 gallon tanks just fine? <No idea; RMF, any thoughts?><<I would definitely be reading, making careful choices here... There is much to be saved in the way of electrical cost, pump noise, waste heat, service life, by making good decisions re pumps... The Sequence series/Baldor motored lines are some faves for the size, application here. Other fractional horsepower pumps are ably reviewed here on WWM: http://wetwebmedia.com/pumpselmar.htm and the linked files above. RMF>> This company also sells a 5000, specifically designed for large ponds and waterfall displays which reports 5000 an hour. Is that overkill or should I add one or two of those in too? I guess two 1800 and two 5000 gives me 13600 gallons an hour claiming about 15 times an hour for the whole tank... realistically maybe 11-12 times an hour turnover? <Probably overkill. 8-10 times turnover should be adequate.> As for the silver dollars not being fully compatible, I will look into giving them a new home. I have just been keeping silver dollars for 7 years now and figured I was pretty good at it. My last batch of 7 didn't die, with the oldest being 5 years old starting in a 55 gallon and moving up to a 120 gallon for the remainder. I just gave them to the LFS before I moved halfway across the country for the job that would allow me to have such a lavish aquarium. What other fish come to mind, that would be an attractive school of 15-20, that could be raised in one 8 foot section (separated by a divider) until large enough to not be eaten by the Arowana? I'm thinking Bala sharks? <A good choice. But also Semaprochilodus taeniurus look amazing in large groups, and are nice Amazonian fish.> I read they get to 12-15" and from my limited experience, are very fast. <Oh yes.> Do they eat plants because I cannot find info saying that they do, but then again, I was wrong about the tinfoil barbs. <Balantiocheilos melanopterus generally ignores plants. It eats green algae and invertebrates, and may nibble on tender shoots, but that's about it.> Maybe 6 months separated, grown to 7-8 inches then set to survive with the Arowana? <You may also be able to get adults via Fish Forums, fish clubs, etc. Lots of people buy them, and then have to rehome them when they get too big.> Are their any other fish you could recommend as I have limited experience with large schooling fish. <There are a lot of nice big barbs. Severums would also look quite nice, and occupy the midwater. They're territorial when spawning, but your tank is big enough that shouldn't be a problem. What about catfish? Sorubim lima is a nice big (45 cm/18") schooling catfish. It's very peaceful, pretty, and quite easy to obtain. It famously likes to swim vertically leaning against plants and rocks, so is definitely fun.> As for the lighting, the timer IS set to go on all at once come 10am and turn off at 8pm. Some sunlight does come through the one window and glass door to wake the fish up, but I guess that is nothing compared to a full 2000+ watts blazing into their eyes all at once. I can turn on the actinics at 10 am, then 2 of the other full spectrums on at 11, and the rest at 12... and then shut them off in the same manner (off to Home depot again for more electric timers). I assume this will still be ample light for the Anacharis and Amazon swords. <Should be. Try it, and see what happens!> And I do have two 3 foot plastic plants draping across the top of my tank which cover an area of maybe 4-5 square feet each. They are located in between the Amazon swords as to not rob them of light. I don't really want to put much more over the plants, but there are still many other places in the tank to add another 4 to 5 of those 3 footers without disrupting light to the live plants. I will give them a try since they are cheap and fairly realistic looking. As for the other plants, I do have an Anubias growing on a piece of driftwood, though the plant is 3 years old, started as 3 leaves, has maybe 30 now, and has only moved about 1 foot across the driftwood (3 foot long driftwood). It used to be house with a Pleco so perhaps his constant sucking of the driftwood would constantly cull the Anubias... or maybe the thick film of algae growing on its leaves is inhibiting it? <I've tried Anubias with my Panaque, and it gets turned into a Swiss Cheese Plant, so I agree with you here!> Ill try out the C. calamistratum when I find it. If nothing else the LFS can order it for me. <Mail order plant distributors abound, and this is a fairly common species, at least here in the UK.> I do have a Sailfin Pleco in there too. He's only about 8 inches long though so he is having a problems stopping all the algae as of yet, though I have faith in him (or her, I cant tell yet). <Once they mature they aren't really algae eaters, so don't hold too much store by this. Plecs generally are omnivores, and algae is only a part of their diet.> As for my substrate, it is just painted black artificial gravel. I add trace minerals for the plants, but I guess that's just not going to cut it. <Indeed.> It will take some time to clean all 200+ lbs of gravel out, but I would say in half a years time I should have 4 inches of laterite enriched substrate in there. <Can't begin to tell you how much I sympathise! Anyone who has grown aquarium plants (or tried, at least) will have been through the mill of changing substrates.> I guess I wont be getting the black ghost knife anytime soon, if ever, aw well. <Again, look out for "second hand" specimens.> Maybe I'll get some water in my 120 and raise him in there until he's big enough for the show tank. <Quite.> And perhaps I misspoke about the snails as a pest, as I want them in their. I have never been able to keep a tank as clean as I do when I have snails in their. <I wonder if Apple Snails would help on the algae front?> I once had a tank with 4 yoyo Loaches in there that cleaned out the snail population, there was a gradual decline in water quality, and an increase in detritus and algae that I fought for a year... I removed the loaches to the LFS and my tank recovered to crystal clarity in 3 months time. <Not impossible.> Therefore, largely based on this single experience ( I know, that's poor scientific form) I like to always have snails. And despite the appearance of (now about 100 mystery snails) snails crawling all over my tank with about 1 snail on every 4 square feet of glass (or I guess acrylic), I find it more peaceful and artful than an eyesore. <Indeed.> It looks to me as though your experience in the trade has done it again. Thank you very much for your assistance. Matt <Good luck, Neale.>

Baby silver Arowana constantly terrified?    2/16/08 Hello, I am writing to you out of concern for my silver Arowana. Guess I should start with the details: 1 baby silver Arowana, 4 inches long (nose to tail-tip) 1 inch "tall" Tank size: 55 gallons (long) currently, once he gets larger he will be moved to a 200 gallon Tank mate: 1 Siamese algae eater, 1.5 inches long (nose to tail-tip) Temp.: 75 - 80F Ammonia: 0 Nitrite: 0 Nitrate: usually <10 I add a bit of aquarium salt (the marine salt variety, not the cheap boxed stuff at Wal-Mart) with each water change (10-20% at the end of each week) <Arowanas don't need salt, and in fact few species naturally occur in brackish water. So unless you have some overwhelming reason to add salt, I'd tend to skip this.> I have had my Arowana for about a month and a half (The tank used to contain gouramis and has been fully cycled for a year.) About a week ago, when I woke up, I found my Arowana, Percival, darting frantically against the side of the tank, like he was trying to swim through the glass. The tank has a hood, of course, and a light which I don't really use at all (sunlight during the day, no light at night.) He looked absolutely terrified, but he was not "gasping" or breathing any faster than normal. He kept swimming at the glass, darting up and down, trying to get "through." He has not stopped since that morning a week ago. He darts up and down the same side of the tank, wearing himself out. Sometimes he rests on the gravel at the bottom of the tank, hiding in his fake plants. This is very scary to see, since Arowanas are supposed to glide gracefully at the surface. Since his snout has been rubbing against the glass for so long, he's got a white "scab" built up. It's not a fungal infection, since it's not strand-like or fuzzy. It only appears on his snout where he has been rubbing it against the tank. I am adding the aquarium salt and a little Melafix to hopefully prevent any infection, though the wound isn't open. <Not a big fan of Melafix, though perhaps useful enough as a preventative. If the wound does go bad, do turn to a "proper" medication.> What could be causing this behavior? He swims like he's terrified, like something is chasing him. I don't know what to do for him, I've tried covering the tank for a day to block out any light, but this hasn't helped. I tried to do more frequent water changes, but he only becomes more terrified and I'm afraid he'll have a heart attack or knock himself unconscious! I hate to see my once majestic baby so utterly frantic for no apparent reason. Please help, and thank you so much for your time. -Amber <There are two likely issues. The first is the size of the tank. Arowanas are open water fish, and they can be easily spooked in small tanks. They will often try to jump, and in doing so, damage their snouts, which is likely the cause of the physical damage you're seeing. The second issue could be the placement of the tank. Things like loud TV sets, banging doors, or simply people constantly moving past the tank can make fish nervous. This varies of course, and some fish settle down quickly, but others do not. In any case, I'd think about whether the tank is in the best place in your home. Do also add some big floating plants to create shade. This will help inhibit its jumping behaviour. Do also review water chemistry; while Arowanas are definitely adaptable, extremely hard or soft water won't be appreciated. Fish tend to be nervous when water quality or chemistry aren't in their "comfort zone". Check water quality an hour or two after feeding, just to make sure that the zero ammonia/nitrite levels you report actually hold 24/7. Cheers, Neale.>

Re: My story and questions... Arowanas, CITES & Ammonia   11/22/07 Neale, <Andy,> Thank you very much for the quick reply. That's what I really like about you guys. Quick and straight forward. Some people may take your advice the wrong way, but you're just being honest and I take it as constructive criticism. <Good oh.> Your reply really gave me a wake up call. I should really stop bringing home fish that attract me from the LFS and start planning a goal for the tank. <Exactly.> That's not something many others would say. <Perhaps not.> I always had the mentally of aggressive fish with other aggressive fish would be a balance but I guess not. <Doesn't work like that.> I will be trying to find good homes for my fellow friends since I am not capable of providing tanks for all the different individuals. I really hate to see them go, but it must be done. <Quite possibly.> Just a few more quick questions, and I'll try to stay out of your hair as much as possible. As of current, do you know if/are freshwater stingrays and Asian Arowanas still illegal in CA/USA. I'm getting contradicting information on this issue and can't find it in Department of Fish and Game web site. <They are NOT legal in the United States. The situation is this: Scleropages species (Asian Arowanas) are listed on the CITES appendix 1. This allows for trade only if the animal in question is captive-bred or otherwise certified to not be reducing wild populations by its sale. So in Europe, you certainly can buy Asian Arowanas. It costs thousands of dollars, and there's paperwork to sign and electronic chips in the fish, but there is at least a trade in captive-bred fish. In the US, Scleropages are further controlled by the Endangered Species Act in addition to CITES, and this prohibits any sale of any listed species regardless of whether captive-bred or wild-caught. Until such time as the ESA is amended to exclude captive-bred specimens of listed species, Asian Arowanas will not be legal within the United States. You can read an FAQ on the topic of pets here: http://www.fws.gov/international/permits/pets.html and specifically on Scleropages here: http://www.fws.gov/permits/faqs/FaqB.shtml#bonytongue > As for the 170 gallon tank, does one Jardinei or Flowerhorn and a Scarlet Pleco (L-25 Pseudacanthicus sp.) sound reasonable to you? <Sounds fine. If you find this works and all your fish are happy, you might well be able to add another catfish, just not a Plec. Arowana tend to be more tolerant of bottom dwellers than midwater or upper-level fish. In any event, start with a few fish, see how things work in terms of nitrates and social behaviour, and then act accordingly.> As for the 55er, what's my best way to correct the circulation issue. Due to it being a concealed tank with pre-cut slots on the top, I am unable to add another hang on filter or external power filter. Should I just modify the Emperor 400 with extended intake tubes to the side corners? <I'd simply add two or three marine aquarium powerheads. There are some nice units with magnetic holders so you can attach them wherever you want in the tank. A friend of mine has some of these called 'Hydor Koralia' in her reef tank and they seem to work very well.> I suppose internal power filters or Wavemakers/water pumps might work, but are very distracting when viewing the tank. Another step would be to do some cutting/drilling work, but I want to leave that as a last resort due to the disturbance it would do to the tank. <Indeed.> What's your recommendation here? <If all else fails, add another canister filter. No single addition to your hardware will have so many benefits: water quality, aeration, circulation, and current for fish to swim into. Powerheads and airstones make viable alternatives, but they don't improve filtration.>

Another question is for human ingestion of ammonia in drinking water. Reading many FAQ's from WWM crew (mainly BF) dislikes the idea of ammonia in our tap water. <Ammonia is toxic and we certainly don't need to consume it, and adding it to aquaria is obviously A Bad Thing. On the other hand, as with everything, it's the dose that matters. Trace amounts won't do humans any harm.> Yet, recently I received another e-mail from my water company stating, "There are no current standards for California for Ammonia. Health Implications Ingestion of large doses of ammonium chloride has been shown to cause headache, nausea, diarrhea and failure in glucose tolerance. However, ammonia is not an immediate health concern, and there appears to be little risk to humans from the ingestion of ammonia in drinking water. There is no evidence that ammonia is carcinogenic. However, ammonia is a source of nitrates and may compromise disinfection efficiency and filter performance. Ammonia is not currently regulated by USEPA. Canada has no guideline for ammonia. WHO has a non-health-based guideline based on avoiding consumer complaints." <Standard answer really. What they're saying is since there's no provable connection between low ammonia concentration and health problems, they aren't going to get sued, and so aren't bothered either way. Given the other problems California has to deal with in terms of water (i.e., actually getting enough to serve the population) I'm certainly sympathetic to them not sweating over the small stuff.> From what I get of this, our water if fine for ingestion? What do you think? <I'm not a doctor (well, I am, a PhD, but what I mean is I'm not an MD!) so I can't really give advice here beyond saying ammonia isn't a good thing to have in water at least from a fishkeeper's perspective. Ammonia is definitely toxic to fish and has been comprehensively proven to be so in laboratory conditions. Even as little as 0.5 mg/l causes death in some species and weakens others to the extent of reducing resistance to diseases such as Finrot. On the other hand, if you have human health worries about your water supply, that's something to discuss with a medical practitioner rather than an aquarist!> Welp that's it for now. Thanks a lot for your time. Reply is greatly appreciated. Andy. <I hope this helps, Neale.>

Arowana compatibility, sys.    12/28/06 Hello there, and happy holidays! <And to you and yours> My family currently has a lovely Arowana at about 19" in length. He's been living in a 46g tank, <!> but we're getting a 100-125g tank soon. <And larger soon afterward I hope/trust> It's about 60" in length, would that be a suitable length for him, since he's the only Arowana? <Not really... may/might I ask, would you like to live in a world that is four times your length?> I've read in other sources that they may develop eyes that turn downwards from being overfed. Is that true? <Mmm, not really from being overfed, but more as a consequence of captivity period... living in small containers, looking downward... running into objects...> He does have a slightly bulging eye (his other eye was damaged & it's blind), <...> but I don't believe we overfeed him. He's on a diet of Hikari Food Sticks, a random assortment of flake foods, bloodworms, and random bugs/earthworms. <ditto...> As far as other fish for the new tank goes, we're a bit uncertain as to what he'd take kindly to. Our local retailer says that teacup rays are suitable (we'd buy only one), <... well... found in S. America... this is... a start... and do tolerate/appreciate similar water quality> and since they're both from the same region, their preferences for water types and everything are similar. Is this true? <Truth? Scarce can I name but fearful thunder echoes in mine ears...> What kind of gravel/sand substrate should we use, is there a recommended type? <Most anything that fosters biological filtration... Covered on WWM> Also, for the simple fact that they have barbs... how likely is it that they might injure the Arowana or us? <Barbs? Osteoglossid fishes? Mmm... not to worry> And also, how much should we expect to pay for a teacup stingray in NJ, USA? <Perhaps a few tens of dolares per unit> Another fish we considered was the Silver Dollar (a group of 6, at about 4-5"). Though I think they seem a bit small because of the Arowana's presence, <Agreed> the store owner assured us that because they're so round and fast, they're safe. <Getting past time to look for/at other LFS's> However, if they are so fast, would they stress the Arowana out? <Yes> And wouldn't he still bite at them, perhaps not to kill, but still causing a sufficient amount of damage? <Too likely in a small volume> As for the tank itself, I tend to stock mine heavily with plants. Would the ray uproot it all, and the silver dollars devour them that quickly? <Very much so...> What sort of balance should we aim for? <My friend! That is beyond me... perhaps yourself!> Thank you, Christina <Thank you, Bob Fenner>

Will this work for my Arowana setup? Hi, I have a few questions I would like to ask today. (again)  First off, I currently have a 75 DAS aquarium
<I'm not familiar w/that>
for a 9 inch black Arowana to live in for "a while."  I understand that DAS have very poor filtration systems, so I recently purchased a magnum 350 canister filter to aide in the filtration.  But I hear that the magnum 350 doesn't have biological filtration. <Biological filtration is exactly what a canister filter is for.>
(also I have bare bottom tank so no substrate bacteria) <Why?  I would definitely put some substrate in there.  In addition to the huge surface area for bacteria, the Arowana will not feel comfortable w/o it & may get freaked out by this.> So I wonder, will this suffice as far as filtration goes?  Another question regarding equipment setup is....the magnum 350 pumps around 300 gallons per hour back to the tank, (I think) will this be enough for circulation for Arowanas?  Because as of now, I am having the DAS system return the water at 600 gph plus the 300 gph the magnum is returning, is this to much for black Arowanas? <no> is to much circulation bad? <no> should I lower the water return on my DAS? <no>   <I would add a HOB filter, like an Aquaclear 500 to act as mechanical & extra biological filtration.  I like to stack them: (bottom to top) sponge, 1" filter floss (polishes water) & Bio Blox.  I rinse the sponge & floss at every water change, leaving the Blox & canister to do the biological thing.> My last question is regarding the black Arowana itself.  At what pH level should I have it live in? is 7.5-8.0 ok?  <Not really a concern> and are there any special concerns I need to know about keeping them?  Please advise... <As you know, they need lots of horizontal swimming room & a good sturdy cover, as they are excellent jumpers.  Try not to feed them feeder goldfish, as they are usually starved & very crowded in holding which causes them to be diseased & not very nutritious.> Thank you <You're welcome & good luck--Pufferpunk> Thank you.

Arowana tank: Crushed coral substrate? No substrate? (11/10/03) Hi crew of WWM, thank you for having so much resources to learn from. <Hi! Ananda here tonight...I'm going to answer both of your emails in this message.> No doubt in a year or two the tropical fish business will bloom more than it already has in part because of you guys. <Hmmm, likely to keep going, anyway, but not necessarily due to us...> Well today I just have one quick question that I can't seem to find any where else.  I plan to care for two silver Arowanas in a 100 freshwater tank and I wonder if I can use crush coral substrate because I have a lot left after setting up my 180 gallon marine tank.   <Two problems with this. One, a 100g tank is too small, long-term, for most Arowanas, some of which can get up to 40" long. Even the "small" ones can reach 28". Either way, they deserve a full-blown indoor pond. The second problem is that these fish prefer slightly acidic conditions, and crushed coral is going to raise the pH to something quite alkaline.> Will it effect the water hardness to suit the Arowanas' life?  What about other fishes? Can I have other fishes with crush coral substrate? <While definitely not suitable for Arowanas, there are fish that will happily accept crushed coral as a substrate. African cichlids and most brackish fish come to mind.> Thank you very much for your assistance <On to part 2> Hi, I have a really quick question today.  I plan to have two silver Arowanas in a 180 gallon tank and I wonder if it's best I don't use any substrate?   <Hmmm... Even in a 180, I wouldn't want to keep one Arowana, let alone two. It's akin to living your entire life in something the size of a jail cell.> Would having a bare bottom better than having gravel?   <It might be, and you get a mirror effect from the bottom glass.> Will that effect that biological filtration of any kind?   <Maybe, but you're going to need a lot of filtration for Arowanas anyhow... think pond-level filtration for an indoor pond.> Because I hear that having a deep substrate produce nitrifying bacteria which is beneficial. <Well, the substrate itself doesn't produce bacteria; rather, it can be a place for bacteria to live.> But I also hear that having bare bottom will be easier to clean the water.   <Definitely easier to clean the tank when it has a bare bottom.> What is the best way to go?  Please advise.   <I vote for an indoor pond of one to several thousand gallons.> Thank you very much. -PHT- <You're welcome. --Ananda>

Arowana Problem Greetings! We have an Arowana.  He has been swimming real low to the bottom of the tank and he is not eating.  We have cleaned out the tank, done water treatments with Ick disease medicine.  Some days he is more active than others, but he is still not eating.   What can we do?  Please respond as soon as you can.  Much Appreciation, Lisa <<Dear Lisa; How long have you had him? I recommend putting the carbon back into your filter to remove any leftover medication for the time being. Because unless he actually has external parasites (which you will see as small white spots that look like salt on his body) you are just stressing him for no reason, meds can be very hard on sensitive fish like Arowanas. Also, you will need to take a sample of your tank water to your local pet store and have them test it for ammonia, nitrite, and nitrates. Make sure they test all three, and make sure they explain what the results mean...your Arowana is probably needing more frequent partial water changes. What are you feeding him? Perhaps you can try an alternate food, like dried bloodworms, Tubifex, or anything else that floats. Some Arows can be trained to take floating pellets. Make sure he gets a varied diet for the best health, but avoid feeder goldfish. -Gwen>>
Arowana Problem Our Arowana had cotton mouth disease. We got medication for it and followed all instructions.   He always eats feeder fish, but lately since the cotton mouth disease he has stopped eating.  What should we do?  Please respond. <<Hello. Exactly which medication are you using? What is the name of it? You said you were treating with an ich medication,  this will not cure your fish of cottonmouth disease! You need a good antibiotic for Mouth rot. Go to your local fish store and ask for one. While you are there, is there any way you can get your water tested? Please test your water and email me the results for the following: ammonia, nitrite, and nitrates. Thank you. Also please note that "cleaning out the tank" can cause more problems than regular PARTIAL water changes done weekly, which is what you should be doing. -Gwen>>
Arowana Problem III Thank you so much for your immediate response.  The medicine we gave Barnabas, our Arowana, was FURAN 2.  FURAN 2 for the treatment of cotton mouth disease.  Today he is swimming around more and this weekend we will try some dried worms or some of the other foods you suggested.  Thankfully, he is appearing to be more active.  Do you have any more suggestions?  Are they're drops we can put in the water that will give him some nutrients until his appetite comes back?  What about vitamins?  Please respond.  Once again, THANK YOU for all of your help.   Lisa Sanchez <<Hi Lisa; yes, there are vitamins you can add to the food he is eating, you can find Selcon at your local fish store, also VitaChem will do the trick. Just follow directions on the packaging. The Furan 2 should help as well, just remember to test your water! Sounds like things are looking better! :) Good luck, -Gwen>>

Arowana Setup Hi There, I already have a 125 gallon fish tank for my 6 inch Australian Arowana (jardinei). I have 2 emperor 400 power filter, two 250 watt titanium heaters, and two 15 inch bubble wand at each end of the fish tank. I replaced the activated carbon of the cartridges...with Marineland's diamond crystal for removal of ammonia and the extra cartridges now contain SeaChem's matrix bio. The heaters are set at 85 degrees Fahrenheit. <Loose the white diamond and allow a natural bio filtration to become established on those four big bio-wheels. That's what they're for. Far more effective and no need to replace. Do water changes to correct spikes until you are cycled. You are testing, I hope. If not, please start> My questions are: 1.) Any comments with my set-up?  All the stuff I mentioned adequate enough for a healthy and safe environment of my baby Arowana? <Will be OK while he's a baby and alone in the tank> 2.) Are the power filters enough? Or I need to add another emperor 400? Because I read an article that the flow of the filters should have a total of 10 times the amount of gallons of the aquarium per hour?  Since I have 125 gallons....I need to have around 12000 of water flowing thru my power filters?  Is two enough right now. since only one fish is in the tank. and it is still small? <Fine for now> 3.)  Does those water agitation on the surface caused by the power filter will be bad for the Arowana ....since supposed to be on the surface of the water all the time......and the water agitation might annoy my Arowana? <He might get blown around a little. But IMO he can handle it> 4.)  if changing water, ...can I use tap water...and go straight to my tank....then I add salt, and Amquel plus , and NovAqua.....safe?  or do I need to age my water first?  I am just worried about the chlorine that goes to my tank........they might harm my Arowana.....before the Amquel plus and NovAqua.....gets the chance to completely eliminate them.   What do you recommend to my problem? thanks, Antonio <Hi Antonio, Don here. For my water changes I use only dechlorinator. I have several 5 gallons bucket which are each treated, but not aged any longer than it takes to draw out the old water. But then I'm blessed with soft, pH 7.0 water. And I stocked with fish that like, or can adapt, to my conditions. I would suggest the same for you. The more your conditions are chemically dependant, the more chance for mistakes/problems. BTW, all this is based on your Arowana being only six inches. He's going to end up over 3 feet long. At some point he will need a bigger tank and a lot more filtration. Do not give him feeders! At some point you will introduce Ick, at least. This tank/fish will be a "bear" to treat>  

Cramped Aussie Hi there, this will be my set-up in a month: 1 golden jardinei (five inches) 1 Pleco (four inches) 30 gallon tank (36 inches long) bare bottom air pump 8 inch air bubble band 250 watt digital titanium heater w/ thermometer emperor 400 power filter do I still need the following to have a healthier tank? 1.) UV sterilizer 2.) protein skimmer 3.) power head what are pros and cons of these? thanks, Antonio >>>Antonio, Are we talking Scleropages jardinei here? This fish gets to be 3 feet long, and REQUIRES a tank of *AT LEAST* 135 gallons. Forget UV sterilizers and protein skimmers (the latter of which we don't use on freshwater tanks anyway) you need to get rid of the fish, or get a MUCH larger tank. If you mean a different species, please clarify. Jim<<<

Cramped Aussie - part 2 Hi there, thanks for your reply. yes....it is a Scleropages jardinei.   It is still very small (5 inches). I am just wondering why you were suggesting that I should get rid of my fish???  It is my pet...and I love him. Anyways.....I really don't think that putting a 5 inch Arowana....into a 135 gallon at the moment is wise.  A small Arowana will not be very comfortable when placed into a very big container.  Maybe once the Arowana becomes 12 inches.....is a better time to transfer to a 135 gallon. sincerely, Antonio >>>Antonio, Most of the time when someone puts a fish such as this in a small tank, it's because they are completely ignorant of the fish's needs, either now or down the road.  This fish grows fairly fast, so unless you plan on providing larger quarters VERY SOON, then you will need to get rid of him. There are lots of "loved" pets that are abused, neglected and by extension killed every day. I hope you plan on providing him with the home he needs. Keeping him in such a tank too long will stunt his growth. Also, an Arowana will NOT be uncomfortable in a large tank, this is silly. They don't occur naturally in small glass boxes, but in spacious rivers much larger than 135 gallons. Best of luck to you with your fish! Regards Jim<<<

Red Algae, DIY skimmer, and Beautiful black Arowana Hi,
<Hi back, MikeD here>
I am some what new to this site but I really enjoy it so far.  Couple questions if you can help.  I have a 75 gallon reef tank and just lately its starting to get over taken by the bad bubbly red algae I think it is.  Any suggestions on how to get rid of it quickly?<IMO "quickly" is always a red flag trouble word. There are many things that will make it go away including 1)increased circulation, 2) RO/DI water,3) increased partial water changes, 4) eliminating "oily" foods and 5) siphoning it off while doing partial water changes. There ARE products available to kill it as well, but use with caution as each has a definite disadvantage to be considered.>  I have had it set up about a year.  Also I have 2 aggressive salt water fish I am moving to a smaller tank anything you can suggest or a site I can look at for a DIY skimmer that's cheap since I only have 2 fish in the tank?
<sure...check the DIY forum here or at Reefcentral.com>  
One last question, in the 125 gallon I am getting a large black Arowana and a white Oscar not sure what else if anything, (dorado (doratto? catfish, sting ray) anything you can suggest?
<Arowanas grow to almost 3 ft and are huge PLUS they are acrobatic jumpers. One will fill a 125 by itself and they commonly kill themselves leaping into the hood/lid....they can jump almost 3' straight up after insects, small frogs and even small birds. their mouth has been compared to a landing barge and their genus name, Osteoglossum, means teeth on the tongue and they consume HUGE amounts of food as they grow.>.  
These fish are paternal mouth brooders would the bright red gravel take away from his beautiful look or what can you suggest for his aquarium to be set up as.
<Almost anything you'd like. The black Arowanas end up silver and almost identical to the silvers. Tankmates can be tricky do to their large size and gaping maws, so I'd suggest caution here....I kept my last one with a Tiger shovelnosed catfish as a tank buddy, that way anything that dodged one was eaten by the other, with NEITHER up nor down safe.>  
I would rather not have it plain.  Thank you in advance for your help.  Tim and Kim.
<Hope this helps. Use caution if you get a little one and raise it. I lost a small baby by feeding it a live spider. The head shaking was evident that it had been bit inside the mouth and it gradually wasted away from the venom over a period of 10 days or so. This IS rare, but it CAN happen, with most spiders cheerfully just considered more food.>

Arowana fish Hullo Robert, This is Ingrid Again!!!! Could you give me the details about Arowana Fish e.g.:- Tank temp.    Vicious/docile ?? <Can be, is a bit of both... More like Sid when hungry/feeding, most of the time passive... easily picked on by more aggressive tankmates> What type of water do they like PH??? <Prefer softer, more acidic, but can/do tolerate wide conditions> What do they eat? <Most meaty foods, offered near, on the surface> Can you put other fish with them? <Yes> How big can they grow? <Two to four feet or so...> How do they breed.? and are they good parents.? <Mouthbrooders... yes> Could you tell me the same for the African Knife Fish? <Please see WWM and fishbase.org re> A million thanks for your time! Best Wishes. Ingrid Armstrong -      -------------[wanted to purchase these fish on Wednesday-[ SA time] if you could reply soonest! <Do read on WWM... Bob Fenner>

Silver Arowana tank size? My LFS has a very active and nice looking 6" Silver Arowana. The biggest tank they can get for me is a 180 gallon measuring 72"x24"x24". They have assured me that a 180 would be big enough to house this single fish when fully grown, is this true? >> When it is fully grown, no. The fish will grow to 60" in length. But in a tank of 180 gallons it will grow only to a somewhat smaller size, and it could be ok to live in a tank that size for a good while. At its full size Arowanas are really fish for the public aquarium. Both Black, Australian and African Arowanas are smaller fish and would be better suited to live in a tank that size. Good Luck, Oliver

Compatibility questions & miscellany... Mainly Aruanas... sys.  - 06/30/06 Hey there, thank you for the reply last time, it was really helpful. <Welcome> Bob had previously helped me identify my Knifefish as Sternarchella schotti, which seemed dead on correct. However, he has continued to grow past the 8" mark; he's about 11" now... is there perhaps another species that he could possibly be, or is he just an abnormally large example? <Could be... either possibility> We also used to feed him various foods, ranging from bloodworms to shrimp and everything in between. However, I've been busy this year (blahh, junior year of high school is evillll) <Correction my young friend. Only certain acts are evil... not individuals, school time frames... Though...> , and my father's rather lax about fancy feeding... <Careful here...> so we hadn't given him live food in ages. When we did start putting in live food again, he showed no interest at all... is there any way we can get him to start again? <Mix some in with the prepared foods... over time...> My father also purchased an Arowana (silver) while I was away at school. Since they both like softer, slightly lower pHs, so I left them together; they haven't fought once. The Arowana is about 13" now. What are the chances of him bullying the Knifefish, or vice versa? <Very small... Perhaps if/when the Arowana is large enough to ingest the knife...> We also have a gold Gourami and Pleco in the tank, both about 5" long or so. <Oh, the Gourami will be inhaled first> Recently, the Gourami's been somewhat subdued and injured... Nothing serious, but there's missing scales and slight dents along his back. <Oh, it's time is coming> Somehow, an Arowana attack doesn't seem like it would leave those marks, and neither does a Pleco or Knifefish. The water conditions are the same as always (pH about 6.5, soft water, well planted and shady), and are holding steady. We have a few cichlids in another tank that are about 5" now, and were wondering if they could get along with the Arowana/Knifefish. <... depends on species, the size of the tank...> I think (though I'm not sure) that the salinity and pH and everything are quite different though; would they be able to coexist healthily/peacefully? <See above> Our Arowana has a few unfortunate things, though. He's been blinded in one eye (which has made him more docile but slightly jumpier) after smacking into the floor before we learned to clamp down the top. <... happens... all the time> He doesn't swim noticeably different, but most of the time when he lunges for food, he'll just barely catch it or miss. He hasn't lost condition though... he's still a fat and constantly hungry pig. But...How should we help him compensate for this, if at all? <Mmm, bigger/est tank, careful feeding of cut foods offered on/with a dedicated "feeding stick"... good maintenance otherwise> The other thing is that the person who sold us the fish told my dad that he would grow to fit his tank. <... uh... no> Disillusioned, my dad thought he'd be fine to stick in a 46gallon tank for the rest of his life, <Not a very good or long one...> especially since he was only about 6" long when he bought him. However... I'd like to know my options for him, just in case. We don't really have the resources for a larger tank, maybe 60g at the most. <... needs hundreds of gallons minimum...> I'd be willing to try and sell him back, or send him to another place, but I'm not sure if his eye will affect his ability to do well there, and I've grown somewhat attached. ^^" If we need to send him elsewhere, are there facilities that we can do so? <Maybe> Are there Arowana species that would be able to fit in a 46 gallon tank comfortably? <No. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/osteoglossiforms.htm and the linked files above. Bob Fenner> Thank youuuu, Christina
Re: Compatibility questions & miscellany  - 06/30/06 Eep! I'm sorry, for the 2nd to last question... I live in NJ, USA, if that helps at all. I'm not aware of any public aquariums or NON-commercial pet stores around here, though I'd be more then willing to drive a bit more for him, heh. <Mmm, give the large/r stores and Service Companies in the "Aquarium" section of your local Yellow Pages a ring re... perhaps they'll know someone with facilities, interest. Bob Fenner>