Chiller, on FW, planted tank? Maybe...  -- 10/26/09
Greetings:
<Salutations>
I have recently built a new sump (working with acrylic is a very handy and cost-saving skill) and coupled it with a Coralife 790P pump to my 72g bowfront tank. Pressure pump is needed to run a Venturi (Mazzei) for CO2 injection.
<CO2? For plants? Better to low-pressure bubble this in through an appropriate baffle>
End flow through is roughly 150-200GPH (throttled for Venturi effectiveness) I have 4x 65w CF lights, said pump, no heater. Ambient room temperature is about 77-78. tank is not exposed to direct (or really any)
sunlight. Temp hovers around 86 w/ glass lids. I since removed lids, directed A/C ceiling vent at water surface, temperature is now 82.5.
<Mmm>
Tank is planted, fish are mostly Tetra. That's the tank.
My questions are as follows:
Does a temperature this high hinder plant growth?
<For some plants, yes; but not all>
I am in the position to buy a PCI CL-650 chiller, 5 years old, at a reasonable price. Is this too old?
<Not if kept in good condition, no>
Even at a good price, would I be able to expect a good amount of life remaining (the internals are spotlessly clean)?
<Yes>
I've looked, and this chiller can pull down 100g 30 degrees. I'm pretty sure my need of only 10 or so degrees (if chiller was bought, lids go back on, so 75-77) would equate to the chiller being on-off-on-off frequently, thus wearing it out faster, but I just wanted to confirm it. Possibly a bad investment?
<Mmm, maybe not needed at all... Depends on the livestock... what are you going to, are you keeping here?>
Should I bother at all with a chiller, provided the tank goes no higher than 82.5?
<I'd try some simple fans blowing air across the top of this tank, and place a heater (or two) and set them for your lower temp.... as you may well find it cooler at night...>
I want to be sure my plants are healthy (I also EI dose), but don't want to invest more money and electricity is not need be. Thank you in advance for all of your help!
-Brandon
<There are a few ways to mediate temperature... Please read here:
http://wetwebmedia.com/chilfansfaqs.htm
And send along your stocking list. Bob Fenner>

Re: Chiller -- 10/26/09
Well, Bob, by directing the AC vent at water's surface, and removing just the plastic lip from the glass tops (thus leaving a 2" running gap along the back), the temperature is hovering right around 80.5. Don't feel a chiller is necessary, since the temp is stable.
<I agree>
Heater is in place to ensure no drastic drop occurs when lights go out.
<Good>
The Mazzei injector is wonderfully efficient; it has a 0.1 pH pull down in roughly 5 minutes (although great
care need be taken d/t this extreme efficiency). My AM1000 reactor just wasn't doing the trick, burned through CO2 too quickly.
<Also understood...>
As for livestock, the fish are tetras, two Boesemanni rainbows, an SAE, Pleco (very juvenile, not enough to ravage plants - yet)
<Which species? There are some that are very appropriate, and others... in->
, and scissortail Rasboras. None of the fish show stress; colors are vibrant (Scissortails actually have a hint of
yellow before the black in the tail fin), no gasping, etc. Plant-wise, I have crypts, swords, and am looking to get perhaps some Microsword or Sagittaria to create a carpet effect.
<Mmm... do check on the species of Sagittaria, Echinodorus... even Cryptocoryne... re their needs. Some are more tropical than others>
Really, I just wanted to make sure I was not going to cook my fish, or plants, but I feel 80 or so is adaptable for most plants, and almost all fish, given it stays stable. Thoughts?
<S/b fine. BobF>

Plant Tanks, Heating Cables, and Heart Attacks - 10/19/2006 <<Hi, Arthur. Tom here.>> Hopefully you can help ease my mind. I am setting up a freshwater planted aquarium and intend to use heating cables submerged in the substrate. Is there any way whatsoever I could be harmed by the following: The cables are powered by a step down isolation transformer with 115 VAC input and drawing 2.46 amps on the input side with a max load of 270 watts protected by a 4.0 amp super time - Lag TT fuse. The transformer powers a heavy duty submerged silicone cable manufactured by Dupla at 48 volts and 6.43 amps on the output side. The statistics I have read indicate the skin give between 2000-50000 ohms of resistance, but a inside the skin only provides 500 ohms. It seems to me that should the cable become cut and exposed, and I happened to stick my arm in with a cut, I would potentially be able to run 96 milliamps through my body (48 volts / 500 ohms)? I have heard that 30 milliamps through the heart can cause cardiac arrest. Does this seem like sound reasoning? The product in question guarantees absolute safety, but I would appreciate opinions by those with more electrical knowledge. Finally, I do use a GFCI, but as I mentioned, this is an isolation transformer. I also will be using a titanium grounding probe. Also, the company is a niche German aquarium company, and I am unable to get any useful information from them. <<Arthur, this strikes me as more than mere concern. Frankly, I'm in less of a position to assure your absolute safety than the manufacturer would be but, based on product stat's you've provided, I would suggest that a potentially dangerous situation while using this product is remote at best. Three options I would suggest would be, first, unplug the heater any time you need to place your hand/arm in the tank. Second, if you do place your hand/arm in the tank with the heater on, keep your other hand/arm out of the tank. Electricity cannot pass through your heart unless there exists a complete circuit through your body. Third, don't use this product, which is the only fool-proof way not to get 'zapped' by it. Tom>>

Using Reptile Heaters  To Heat An Aquarium  - 09/13/06 Hi WWM crew. First of all, thanks to Chuck for his input and cautions. The advice was much appreciated, and I'm now revising my stocking list accordingly. I was reading a number of FAQs on WWM (and other sites) regarding the issue of substrate heating in FW plant tanks. And was debating whether or not it was worth it. However, the one thing that kept popping up was people discussing how annoying they are to deal with. At first this seemed strange to me until I realized that most of the heat cable devices are designed to go IN the substrate. Yikes! This was not my intention when I first read/heard about the idea. I have a number of heating devices (heat pads, terrestrial heat cables, etc.) left over from keeping various reptiles, and my intention was to attach whichever one fit best on the outside of the tank (underneath the substrate) using silicone or electrical tape. I then planned on hooking it up to a rheostat (also left over from reptile keeping) and tinkering with that until the substrate surface at 1.5" read 78 degrees. These numbers are based on a water temp. of 76 degrees and a total substrate depth of 3". Do you see anything horribly wrong with this plan? All the devices in question are safe for use in high humidity and the tank's stand has an open top for use with overflows and such. So the safety issues should be covered. I'm still deciding whether or not it's worth another outlet, but wanted to check to see if this method would be acceptable for reaping the "benefits" of a heated substrate or if you have to have the cables IN the substrate. If that's the case... I might leave that idea by the roadside. Thank you all again for your time and dedication. -Tyler < Check with the manufacturers of the products to see if they can be used for this purpose. If one of these products caused a hot spot under the aquarium it could break or crack the glass if there is too big a temperature differential. Who is then responsible for the damage? If it was heating the water then warmer water would rise in the tank and be replaced with cooler water. Under the gravel you have restricted water flow and the circulation may not be enough to cool the glass. It would not be worth it for me and I would purchase a high quality heater.-Chuck>

HEATING COILS IN A FRESHWATER PLANT TANK I am setting up a 30 gallon fresh water planted tank.  I just finished installing an under gravel heater made by Hydor. I am fairly certain that their heater cable is just for warming the gravel to improve water flow around the plant roots and not to heat the entire water column. I was also going to install at least one standard 100W Jager water heater. The heater cable is connected to a temperature probe that mounts in the water column and controls a thermostat powering the cable. My question is what temperature should I set the cable thermostat to? If I set it at the same temp as the Jager water heater will the gravel heater ever come on (i.e., since the water column is always at that temp)? <Depending on how thick the gravel layer and the porosity of the substrate you could have a significant temperature differential between the substrate and the ambient tank water. Place a sinking thermometer at the bottom of the tank buried in the sand and another floating thermometer at the top of the tank. Read the difference. In order for water to flow from the gravel up to the tank it needs to be warmer than the existing tank temperature to rise up through the sand and create a flow. I would set the water temp at 78 degrees and the cable at 80 and monitor the temps.> If I set the gravel heater a few degrees higher won't the gravel heater always be on until the water reaches the temp set on the gravel heater? <If the tank water temp is higher then you are wasting your time and money on these cables.> The instructions with the cable are obviously lacking any help. Thanks if you can help with this problem. Also would a small UV sterilizer be valuable in keeping my investment disease free? I will be running an Eheim canister filter.  John Malenchek < A UV sterilizer helps but there are no guarantees. I would invest in a quarantine tank myself and be a little patient.-Chuck>

Substrate heating  Hello Robert, The argument for substrate heating in FW planted tanks is that the slow H2O column exchange within (as the bottom is typically 1-2degrees warmer than the column itself) will help the gravel "sweet" for a longer time than without it. There are other arguments for it as well (though they focus on the needs of the plants themselves). <Yes> I know that some people will try to heat the whole tank with the cables, though I have had good luck using them for warming the substrate only. I am convinced that my 5 inch "deep sand bed" is providing denitrifying benefits in my planted discus tank, though I have no #'s to substantiate this (what do you think?). <I think you are probably correct... I would do the same.> Since the the substrate depths between a typical planted tank/reef tank are roughly similiar, in your opinion why don't we see cables used?  <Mostly the expense involved... along with basic ignorance... folks don't know... it took me decades of "campaigning" to help raise skimmer, cyanide... issues. The "founder effect" in the hobby is greatly slowed by its huge "turnover" rate... most folks don't last a year as aquarists> Maybe we could use DSB's in our display tanks this way, not having to worry about anaerobic conditions so much? Have cables been used in the past? <Yes and yes. Not that uncommon in Western Europe for instance> Thank You, Erik Nelson P.S. BTW, for the occasional hydrogen sulfide pockets that do appear (mostly around a dead rhizome), I think my pair of Golden Dojo Loaches actually like the smell! They remind me of a couple of naughty dogs in the garbage can! <Again, agreed! You should memorialize your keen observations, have them published at least as feature articles in the hobby magazines. Do consider this. Bob Fenner>

substrate cables again (note: add link) Hi Bob, Sorry---I forgot one thing in my last E-mail to you. In the substrate section of the plants section of your site, under "Further Reading" could you please list a ref. to "www.thekrib.com"? This is THE website for planted aquaria!!! <Ahh, will do so on the moving about of your message here. Do have this site listed on our "Links Pages"... a real winner. Bob Fenner>

Re: Temperature Dear Robert, My son-in-law likes to keep the temperature at about 72 f. He claims that tropical fish like warm water. I maintain that such high temperature breeds bacteria, nitrite, ammonia etc. I contend that he should lower the temperature. <Mmm, a tough general question...> Could you please advise us what is the ideal temperature for tropical fish? <Depends on species, gear involved, the aquarists wishes (more rapid growth, but more money for filtration, aeration, lighting...)... but something in the mid to upper seventies F. is "about right" for the broad mix of "tropical" fishes offered in our interest. Lower temperatures (lower seventies, upper sixties F.) are tolerable to many species identified as "tropical", and keeping temperatures lower is more "safe" in terms of induced metabolic rates, dissolved gas concentrations, higher stocking densities, costs of operation... but most folks would rather see their fishes, invertebrates moving about more briskly, more colorful, growing faster, reproducing... most often tied in with warmer water. If, where in doubt, by species, you can find useful information on temperature range of many species (in the wild) posted on www.Fishbase.org Bob Fenner> Thank you, and best regards Joe Carabott

Is the tank too tall ? My girlfriend is planning out a freshwater tank (55 gal.) to be used for freshwater plants. She is planning to put various sword plants, grassy plants, some slender spike rush. The tank is 23 in. tall. Will she be alright with 3 40w. fluorescent bulbs or should she go with a 220watt power compact system because of the depth of the tank? Also, do you think underwater heating pads are a necessity or are they just a pain in the *&#@? >> Wow, a plan, and such planning! Sounds like you two are candidates for my "favorite types of fellow hobbyists". I would definitely go with the compact fluorescents if this were my tank... and maybe build it and the canopy to house it as something that can be raised/lowered over the top of this tank...  Heating the substrates of planted systems does have its advantages... especially in cold room settings, with very tropical plants... but for your application, I'd look into using a slow-circulated undergravel plate arrangement with a heater for the tank at one end... enclosed by a riser... and a simple, slow air-lift at the other... pulling the warm water gently under the plants, substrate. This and other heating strategies for planted tanks can be found archived at the URL:www.wetwebmedia.com Bob Fenner