Dying Shrimps And Crabs, But Not Snails Or Fish 7/29/10
Hello crew!
<Hi Jennifer>
I have a low light reef that has been up and running for over a year, but recently I've been slowly losing my cleaner shrimp and Emeralds Crabs. It's possible a few hermits have disappeared also but I'm not 100% sure.
My fish, corals and snails are all perfectly fine. I use IO salt kept @ 1.025-1.026, PH is fine and stable, no nitrates or ammonia, weekly water changes with treated and treated tap water, I haven't recently tested calcium, Mag or Alk but there is plenty of healthy coralline algae. The only think I can think of is the animals I'm losing are the type that molt and I don't recall seeing many molts lately. These poor creatures have been in the tank since the beginning and have now been slowly dying for about 3 months. They don't get mangled or eaten in any way, I find them looking sick or already dead. I've tried taking the sick ones out and setting up a separate tank, even trying RO water in the hospital tank instead of the tap water in the display. The only thing the same in both tanks is the salt. Is it possible there isn't enough iodine in IO's salt lately? That seems unlikely to me, but at the same time do you think that makes sense since only the molting animals seem to be dying? I've never seen an iodine test, perhaps it's time to look for one. Any help would be appreciated!
<Two things come to mind. Are the shrimp and crabs getting enough to eat?
And, lack of iodine can cause problems like this as iodine is necessary to ease the molting process. A test kit isn't necessary in my opinion, just follow directions on the iodine/iodide label. Do not depend on the iodine
level in the IO salt, and for that matter, calcium or magnesium as these elements are slowly depleted by the animals/algae that require this. These parameters should be tested regularly and supplemented when necessary.
If your fuel gauge didn't work in your car, would you always know how much fuel you have remaining, or would it be "I think I have enough left".
James (Salty Dog)>

Crustacean deaths... env.  - 6/21/08 Hello WWM Crew, Sorry in advance for the long letter, but if I cant find the problem, I will have to give up my reef tanks (and I don't want to do that). I have attempted to maintain a reef tank now in some form for the last 3 years but have been plagued by the same problem for almost the entire time. Crustacean death. I have posted on reef message boards several times but never seem to get any answers. Without the hermits, algae has become a big problem and eventually overtakes my corals and becomes a pain in the butt. I try to mitigate the contributing factors that lead to blooms, but it always happens eventually. The advice given in crustacean section on your site however has given me hope that maybe, just maybe, someone can help. I am currently running a system with a 65g display tank, a 29g display tank, 45g sump, and a 10g fuge all  plumbed together. I have an AquaC skimmer in the sump, CPR BakPak skimmer in the sump, 2x65w PC on the 29, Icecap 660 with 4x30w HO on the 65, 65w grow light over the fuge (always on), and 2 Ebo Jager heaters in the sump. The fuge has a 5? DSB of CaribSea "Seaflor special Grade Reef Sand", <Mmm... their oolithic, "fine" coral sand is much more preferable> and both display tanks have DSBs with plenums using the same aragonite sand as in the fuge. The basic theory I wanted to use was based on the technique used by the people at GARF.org (plenum use, lighting scheme, supplement additions, <What used here, with what testing?> etc. They call it their ?bullet proof reef? system.) <I would not use this description> I stick to their recommended supplement addition plan using SeaChem supplements (reef plus, complete, calcium, advantage calcium, and builder). <... Mmm... you should read re the actual use of the ingredients here... not all necessary...> My tank parameters are Nitrate 0, Nitrite 0, NH3/NH4 0, pH 8.1, Alk 3 meq/L, specific gravity 1.026, and salinity 34. <This last is a bit low> These measurements have been stable over the course of a year, remained constant throughout the entire day and night, and are the same when measured in each tank or the sump. I use an auto top off device from a reservoir of RO/DI water to maintain salinity and the Ca concentration has remained around 300 mg/L. <Also a bit low... I'd be reading re alkalinity, Calcium and Magnesium, eschewing the use of Calcium Chloride...> There is no trace of copper in the tank (measurements taken with 2 different tests with low limits of detection). The temperature does drop in each tank over the course of the night by around 2 degrees F but I didn't think that was a problem (Maybe I am wrong?). I have checked for stray voltage with a voltmeter and got nothing. The hermits (blue legs mostly) die within the first 24-48 hours. Some seem fine at first while some remain still upon addition (drip acclimatizing method used). Over the course of the next week or 2, I find many bodies and the remaining crabs remain for the most part non-active. Additionally, amphipods, copepods, and any kind of shrimp or crabs seem to always die within a few weeks. <Almost assuredly due to a chemical anomaly...> I have set up several ?experiments? to try and find the source of the death. First, I set up a 20g tank outside my looped system using water from my sump and added some live rock. This tank, along with a separate 20g tank that was already set up in a different area of the house, will serve as my control tanks. Next, I checked all the tanks to make sure there were no live hermits remaining from previous additions and that there was an ample amount of shells in each tank to help rule out competition. Then I added 20 blue leg hermits to the 65g and 29g display tanks, 10 hermits to each 20g control tanks, and 5 to a separated partition of my sump. After 24 hours, I counted 12 live (but non-active) in the 29g, all 10 in each 20g tank, all 5 in the sump, and only 2 in the 65g. After 48H, all were dead in the 65, the 29 went down to 4, but the 2 20g tanks and the sump still had all their starting hermits. The remaining crabs in the 29 died off by day 30. The water parameters remained at the constant level previously mentioned above for the entire experiment. This experiment was repeated a month later with new hermit crabs from a different store with very similar results. Considering that the only difference between the display tanks and the other areas that hermits were added (the 2 20g tanks and the sump) was the use of a DSB with a plenum, the only solution for the death that I can think of would be the plenum. Could it be producing something toxic to crustaceans?... <Possibly... but more likely an interaction or lack thereof with your supplementation, salt mix properties> Or, am I overlooking some other factor that may be the culprit? <What brand salt mix do you use?> If nothing else can be identified as a potential source for the deaths, I will start the process of removing the plenums (even though it means completely taking down my tanks). Thanks for any help. <Again... Please read re the actual ingredients in the supplements you're using... and seek to maintain Ca in the 400-450 mg/l, ppm. range or so, Mg about three times this in conc. and Alk. in the 8-10 dKH range... I do think the supplementation is your source of trouble here. Bob Fenner>
Re: Crustacean death   6/22/08 Hello again, Thanks for the quick reply! So I have to say, before finding your site I thought (maybe even naively) that the method described by GARF was awesome? and thus the method I wanted to use. As time went on and my problems with crustacean death drove further and further towards the cliffs of insanity, I still defended their method in my head (and from my less and less fish tank supporting wife) and thought there must be something else causing the problems. But now, after testing every hypothesis I have had?. And searching your site for opinions on GARF, I feel? well... kind of stupid. If the supplements that I ruled out as a cause (because its what GARF said to do and that CANT be wrong) are the problem, then great? at least I can get back to having great reefs instead of algae blobs of death. I could use some advice though on what I should do about fixing the supplement usage. <Much posted re on WWM, elsewhere. I would definitely do away with any use of Calcium Chloride> After searching the site for supplement usage and views on SeaChem products (like the ones I am currently using) I found mixed opinions. I actually found some advice that recommends the exact products and doses that I am currently using?. ?Treat tank with Sea Chem - Reef Plus TM. Reef Complete TM, and Reef Calcium TM - 2 times usual dose three times a week - These are liquids are added to the reef water. <I understand, and these are fine products, miscible to degrees... I just would not use all, and not at more than measured results dosages> Use Sea Chem Reef Builder in make up water every other time you add make up water. We use two teaspoons per gallon. Use Sea Chem Reef Advantage in make up water every other time you add make up water. We use two teaspoons per gallon.? <... do you understand the simpler interactions twixt and among the components of these products? The testing for same? It is NOT recommended to blindly mix in and add...> To answer a question you asked, I use Instant ocean salt mix (and have been slacking on the water changes for a while? its hard to want to work on the tanks when they are a source of such pain, frustration, and failure?. No excuse though). <Ahh, understood> Anyways, I can't reiterate enough how thankful I am for your attention and help. There was a dream that was my reef tank. You could only whisper it. Anything more than a whisper and it would vanish, it was so fragile?. <Mmm, need not be so... either a whisper, or dream> There was a dream that was my reef tanks. It shall be realized (with the help of the awesome WWM staff). These are the wishes of Marcus Aurelius. (Sorry, its late Saturday night and I have had a few beers?). Thanks again! <Ahh, one of the great Roman Emperors... will our time ever see such leadership in the U.S.? I do hope so. Cheers, Bob Fenner>

Mysterious Crustacean Deaths - 01/26/07 Hello Bob and Crew, <<Greetings JP...Eric here>> I have pined over previously answered questions and faq sections but I still have a mystery.  I have a 20-gallon long "soon-to-be" reef that was set up four months ago.  It currently houses... 1 Kupang Damsel 1 Allen's Damsel 1 Blackcap Basslet 1 Fire Saddle Clown 1 Pink Tip Green Bubble Tip Anemone 1 Green Bar Goby 1 Candy Striped Pistol Shrimp <<Wow, an aggressive selection of fishes for this small tank...not much room to establish/defend territories.  Also, this tank is about half the "minimum" size it needs to be to house the anemone.  Add to that the fact that you will soon be adding sessile invertebrates and you have a ticking bomb on your hands.  Please do read our articles/FAQs re anemone systems/care/et al by starting here and following the associated links in blue: http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/bubbletipanemones.htm>> I also had a Horseshoe Crab, Cleaner Shrimp, and a Pom Pom Crab. <<The Horseshoe Crab is also inappropriate (many are from "temperate" waters and sold as "tropical" animals) and grows too large for this tank>> All was well in paradise until I did a water change a week ago. <<uh-oh>> The Cleaner Shrimp died the next morning, the Horseshoe Crab died two days later.  The Pom Pom Crab never reappeared after an apparent molt about 5 days ago.  Ammonia is 0, Nitrite 0, Nitrate shows a little (due to the maxed out fish load certainly), Temp is avg 81-82 degrees, and Salinity is .0124. <<Hmm...it is possible these events are coincidental...a result of building toxicity or depletion of essential bio-mineral content in this overstocked system...or even caused by a rapid change in pH and/or salinity during the water change>> Now 9 days past the water change, I added another Cleaner Shrimp and he died almost instantly.  I floated him for 15 minutes then added some tank water to the bag, waited another 5 minutes and released him into the tank. <<This is not an appropriate acclimation procedure for these crustaceans.  Shrimp/crabs are very susceptible to small changes in pH and salinity and are often "lost" to improper acclimation.  A slow drip in to an open container is the best way to acclimate these creatures...can be easily accomplished with a bit of airline tubing and valve.  Try a Google search re "drip acclimation" for more detail>> From previous info I see possible culprits as this: 1) I have a dog that is given Flea medication that could have been on my hands, although I made virtually no contact with the Shrimp when adding him. <<But what about the water/containers?>> 2) The pH of my tank, which measures at 8.1, is far different than that of my LFS. <<Ahh, a very likely culprit (would also suspect salinity to be quite different)...demonstrating the need for proper acclimation>> 3)  I started the tank with uncured rock many months ago and some type of parasitic life form came in on that rock (which I left alone for two weeks before adding the cycling fish). <<I think this to be unlikely>> The third is my major concern because the first Cleaner Shrimp was great and then all of the sudden showed a white patch that I later learned from a biologist friend was probably a nematode.  This patch appeared after I added him to the tank. <<Mmm, maybe...may also have been from some physical trauma...or a secondary environmental condition from out-of-balance water chemistry>> I really want to have inverts in this tank and Bubble Tip Anemone is doing wonderful, as are all the fish.  What do you folks think is going on? <<Honestly mate, unless there's something about your water change routine you haven't explained, I think it is a combination of an overstocked tank and improper acclimation process>> Thanks, JP in SC <<Happy to share.  EricR...also in SC>> Re: Mysterious crustacean deaths   2/12/07 See info in bold, I usually change the water one a month.  Water density is usually 1.023 or 1.022.  Thanks for hypothesizing. M <What is "normal"?> > Invert Deaths....more info > Good Afternoon, > I suspect that you are not going to like some aspects of my system but I am hoping that you may see something I don't. I have a death issue. I have > had a red crab, emerald crab, peppermint shrimp, camel back shrimp, sally lightfoot crab, and Hawaiian pom-pom crab die over the past 5 months for > no reason.  Usually little bits of them are floating at the top of the tank one random morning, but never the next day. I have a *55 gallon tank* with a > yellow tang, coral beauty, flame angel, fire fish goby, percula clown, yellow headed watchman goby, scooter blenny, and mandarin goby (unrelated > issue: not doing so well - I didn't read your article first). There are a few polyps and a few mushrooms, lots of snails, pods, various worms, etc. > The tank also has about 60 lbs of live rock. Filtration: Magnum 350, Skilter 250, and an Aquaclear 30/60. Lighting: 110w high output compact and 80w > fluorescent blue actinic.   A handful of peppermint shrimp, small hermit crab, and one large cleaner shrimp are apparently doing pretty well, > because every so often I have a tank full of larvae-looking things, not sure who from but they look different every time. *Water parameters are > all normal*. I thought I might have had a mantis, but haven't seen anything, and the snails and hermits are doing fine.  Of all the fish, I suspect the > yellow tang, but everyone at the LFS's scoff at the very suggestion. I bought a coral banded shrimp last night, in the hopes that a more robust > crustacean would "make it" vs. whatever is doing them in. So far so good. Any thoughts? > <Before I "hypothesize" would you mid re-sending this email along with tank parameters? Nitrates, nitrites, ammonias....etc? I also did not see the > tank size...water change regime....more info please?> > Thanks for your time, you guys have a great website, it has prevented me from making many mistakes. > Marshall > <Adam J.>

Alkalinity and hermit crabs... I'll say! Not even trying to read   8/23/06 Greetings, I recently have had a horrible experience losing about 40 scarlet hermit crabs on two separate occasions.  The hermits were added just after cycling the tank. <This could do it>   The symptoms before loss was extremely unusual -- complete stillness for a period of time, and then crawling out of their shells with no apparent signs of distress, <! Crawling out of shells, stillness are apparent signs...> climbing around (usually upward) for a time, and eventually dying without ever going back into their shells.  The first time I had a huge loss I found out that my water had an unexplained nitrite spike.  (Unexplained because there was no ammonia spike before that -- I had been testing daily). <...>   I believe that the new saltwater I'd been mixing up is the problem (as it tested at .5 in ammonia upon mixing), and changed salt mixes.  But a few days later I had a second die-off.  After testing my water quality, the ONLY thing wrong with the tank is that the alkalinity was outrageous. <Also toxic...> Like someone who didn't know better, I'd been trying to combat my continuously dropping ph by adding buffer about every other day. <How?> I'm told that this caused me to have a high alkalinity.  Is this fatal to hermits? <... yes> I also lost my peppermint shrimp on the second occasion I lost a bunch of hermits, but the ghost shrimp in the tank were not affected.  Do the symptoms I mention re the hermits sound familiar? <Oh yes... as you would know had you followed directions before writing us and read what is already posted...> I'm told it is extremely rare for them to leave their shells. I have stopped using buffer and am still battling a low pH, which remains about 7.9 to 8 no matter what time of the day I test (morning and night).   My substrate is aragonite ("live") from Petco.  Right after doing water changes without buffer to decrease the alkalinity, the few crabs I have remaining got more active and are doing fine, despite the lower pH.  Did I read on here that new substrate can affect pH in a negative way? Thanks for your help! Emilie <Have just skipped down. Please start reading here: http://www.wetwebmedia.com/hermitdisfaqs.htm and the linked files above... "But wait, there's more!"... Keep reading re the other issues you have questions re above... the search tool, indices... BobF> - Help, Crabs Dying - Help! We have a 72 gal bowfront that has been going for 8 weeks now, it has DSB 4-5" of .5 - 1.0 Aragonite (LS from LFS to seed it), 50 lbs LR and a 20 gal refugium. We never saw it cycle that we could see, thought it was due to LR (was in another set-up before we got it, then it spent 4 weeks at LFS while we figured out the refugium!). We slowly added about 13 hermit crabs, 2 Elec. blue, 3 Scarlets, 3 dark ones, 5 light brown with striped legs, a few snails, 1 light foot Sally or something like that (pics on your site look more like a different one), 2 emerald green crabs, 1 brittle star, 1 sand sifter and 1 serpent. All was going well, so we added 2 small ocellaris (1 died trying to hide in the overflow, the other is doing well after healing from a wound also trying to hide in the overflow box). We then added a Coral Beauty - that was 2 weeks ago. When we bought the Coral Beauty we also picked up 1 piece of LR with a cave in it as the LFS said the Coral will want to hide. We (shame on us - also didn't think of it at the moment) didn't quarantine the LR and we have seen the hermit crabs and the Light Foot on it, all just 1 - 2 days before they died. Could there be something on the LR that died or is dying that they ate that killed them?  <I doubt it...>  The Coral LOVES the cave in the rock and hides there at night and when she wants to rest, should we take it out anyway?  <Whatever damage that would be done has been done... I'd leave the rock in and advise you to not do this in the future. If the coral beauty is doing well, then generally speaking your tank should be fine. These fish qualify as the proverbial canary in a coal mine and will show the affects of water quality issues long before hermit crabs will.> Now we think we have lost (I am not sure if they were dead or could be molted parts I found) about 4 of the hermit crabs and the light foot Sally in the last 2 days.  <Molted is very possible.>  I have checked the water many times and cannot find anything wrong with it, even took some to a LFS to have them double check, they said O.K. as well.  I found some razor Caulerpa in the refugium (must have come in with the feather Caulerpa I was seeking and the Prolifera) that might have been going sexual - tips were turning white. I pulled as much of it out as I could find and put in a PolyFilter, although I had a tough time getting the PolyFilter so that no water was going around it. I had also found some hair algae starting on the LR 3 weeks ago, took out that rock, scrubbed it and bought a filtration unit that is not a R/O D/I, but I tested the water it put out and it took out all phosphates and silicates (are there other things that the R/O D/I will remove that could be the problem?).  <Sometimes silicates, but most often problem algae is actually helped along by the aquarist - over feeding, long light periods, poor circulation, etc. Please read here: http://www.wetwebmedia.com/algaeconMar.htm >  This was put together by a LFS/Reefer that works for the water department here in Portland, OR.  Now I am seeing a little bubble algae, and what may be some red Cyano algae (maroon in color, but not hairy, more flat like the coralline algae), but I have Scarlet hermits left and the 2 emerald green crabs, I thought they would take care of these.  <There are desirable algae that look like this... unless it looks like a very thin, almost transparent layer, I'd leave it be.>  I also have a Aiptasia Anemone that is growing slowly, but I just read how to get rid of it, so I will try before it spreads. I have a CPR PRO 20 gal refugium below the tank with a 5" DSB and 6 pieces of LR, 36 watt light 10K PC, running it opposite times as the main tank lights.  <If you are using Caulerpa, I'd suggest you run the light on the refugium 24/7.> I have been reading on the site for days and it seems like there could be many things killing the crabs, but it is hard to narrow it down. The fish seem to be doing fine, as are the star fish and snails and there are other types of feather duster type things and 3 mussels on the LR that seem to be open most of the time - so I am confused!  <Hermit crabs die... I wouldn't make a big deal out of it or continually try to find a cause. They are combative and often displace each other for their homes. No worries.> Any help in narrowing down the culprits would be greatly appreciated!  <Could be no culprit at all... hermit crabs are collected in massive lots and there's no way for you the hobbyist to know what kind of condition they are in. Again, given that your Coral Beauty is doing well, I wouldn't worry too much about the crabs.>  The refugium did come with a protein skimmer and I am trying to adjust it correctly (not exactly sure what that is for a newer system), sometimes I get lots of green water - it has an overflow to a jar - with some dry stuff on the sides of the cup and other times it is mostly dry stuff with very little water - is this out of whack?  <I personally go for the drier stuff, but either one is good.>  Not doing a good job?  <Doing a fine job.>  Not a big enough skimmer?  <Probably not in the long haul, but good for now.>  Started it too soon?  <Not at all.> I have not put any additives in the tank as far as Ca or Iodine, etc. and the crabs do NOT have access to air (didn't find that part out when reading about them originally, only saw that comment after I had problems).  <Hmm... again, wouldn't be too concerned.> Not sure what else to ask or say, would appreciate help quick - since we did not have this problem up until 2 days ago, we purchased an anemone and some soft corals, but left them at the LFS for what we thought would be only a few days until we got our canopy done for the lights (we are putting up 2 - 250 W MH, and 2 - 4 ft 110 W VHO Actinics), but now I am not sure what to do?  <Take a deep breath and relax... take your time, do not rush.>  Do I ask the LFS to keep holding them since we are having a problem, for how long would be reasonable?  <I'd wait a full six months before adding the anemone. Your tank is very new and needs more time to mature before you tackle the more difficult marine life. I'm sure the LFS would say different but honestly, they are just trying to sell you something. Likewise, corals should wait another couple of weeks. In the mean time, enjoy what you have and don't sweat the hermit crabs. Good things come to those who wait. Or as someone I know says, nothing "good" happens fast in a marine tank.> The rest of the hermit crabs seem to be moving around well, etc. and we have lots of extra shells for them to change into (several have changed already).  Thanks, sorry for the long post.  Anne & Rick P.S. Water tests as 0 ammonia, O nitrites, 0 nitrates, pH 8.2, SG 1.024, don't have an alkalinity test kit yet (trying to research which type we want first), but at LFS, they said it was good (forgot to ask what that was), also don't have a calcium test kit - shopping for one of those as well. <No worries. Cheers, J -- >

- Help, Crabs Dying, Follow-up - Hello, I e-mailed last night (early this morning) about dying hermit crabs and 1 light foot sally -MIRACLE - the light foot sally is still there (I guess it molted?) - also, some of the other hermits I thought died seem to be back as well - I was confused as all the water parameters seemed to be very good and muscles, etc. are all still open 90% of the time... Sorry for the panic, but I did notice that the "body" of the lightfoot didn't smell (probably because it was just the shell?).  <Yes, the molts look just like a dead crab, but as you mention don't smell like a dead crab...> I guess I will now be more experienced about jumping to conclusions when I find a crab "body" - Thanks for listening and any suggestions made from the previous post will be appreciated anyway, as I had some other "telling" factors that could show a problem. <Yes... is the reason I suggest you take a deep breath and relax... no worries.> Thanks!  Anne & Rick <Cheers, J -- >

Dying Hermit Crabs and dead Cleaner Shrimp Hi, <Hello there> I recently bought some hermit crabs and they are seem to be dying, not dead yet. First few days they were doing fine, feasting on the algae. But today I can't seem to find the small dwarf hermits and the bigger red leg hermits are not moving, may be moving just slightly. Just a few weeks ago, I also lost a cleaner shrimp. I had it for almost a year and for some reason one day it started to fall off of the rocks all by itself and few days later it eventually died. <Something's wrong here> All my water parameters are fine. Zero copper and nitrate and phosphate are undetectable and ammonia and nitrite are zeros and also 410 mg/l Calcium, 5 mg/l Strontium, 1400 Magnesium, 3.5meq/l Alkalinity, 0.04 mg/l iodine and 8.2 PH. Salinity is at 1.024. <Mmmm... your alkalinity is way off. Please see here: http://ozreef.org/content/view/87/2/> My 29 Gallon tank has Eheim Classic Canister filter, Teco Micro Chiller, UV Sterilizer, 96 watt of Tek 4 24" T5HO lights, and Aqua C Remora Pro Skimmer which is an over kill for my tank. I use for chemical filter media SeaChem's Matrix Carbon, Phos Guard, and Purigen. And for biological filter media Eheim's Substrate Pro. I started my tank year ago and I used SeaChem's Cupramine twice because of my yellow tang's white spot disease. But eventually the tang was cured with SeaChem's Para Guard in a separate 10 gallon hospital tank. The two times I used the copper I moved the cleaner shrimp to separate tank and put it back after copper readings were zero for at least a month and I never had any problems with the cleaner shrimp and it was healthy. Recently I started to use the Tap Water Filter that I bought from Dr. Foster and Smith online because of silicate in our tap water. Our tap water has so much silicate that I run the water through two Tap Water Filters simultaneously to get zero silicate level.  I don't have RO/DI and we are planning to move soon so I did not want to purchase one, yet. Also, I've been adding SeaChem's Calcium, Strontium and Reef Buffer for about six months to get some coralline algae to grow in my tank plus I wanted to turn my tank into mini reef some time in the future. <This may have been the beginning of your alkaline earth/alkalinity imbalance> My tank is fish and base rocks only tank for now. I've ordered some live rocks from Florida but because on the hurricanes last year it has been delayed. I don't know what could be the cause for the death of inverts in my tank. I'm guessing that it could be poisonous diatom algae or my strontium and/or iodine level is off the scale and my test kits are wrong. But then the fishes should be affected too, right? <Likely yes> I don't have a clue to what has happened to my tank. Why the inverts are dying in my tank. Please help, I really like to figure this problem out soon before whatever gets to my fishes also. Thanks in advance for reading through the story of my tank. Hans <Good record keeping, and relating of your system, circumstances... I do think that a dearth of alkaline reserve is at play here. You can read re such developments on WetWebMedia.com and how folks go about curing them... you may even get by through simple additions of baking soda. Please start reading here: http://www.wetwebmedia.com/hermitdisfaqs.htm and here: http://www.wetwebmedia.com/shrimpdisfaqs.htm then here: http://www.wetwebmedia.com/calcalkmar.htm then on to the Related FAQs where they lead you. What do you think? Bob Fenner>

Re: Dying Hermit Crabs and dead Cleaner Shrimp Hi, <Hello> I don't understand about the alkalinity. I read that alkalinity of 2.9 - 4.5 meq/l is safe and that I should only worry if it goes down to 2.8 meq/l. As for my dKH it is 9.8. <For these animals this is so> I read some of the hermit crab deaths but mostly it was mysterious deaths. <Mmm> Right after writing the email I used lot of carbon in my filter and some how the hermit crabs came to life after a day. They started to move around and now they are all ok except for one which died in a fight with each other. <Ahh, a clue> I haven't used carbon in a while because I switched to SeaChem's Purigen a while ago, but I was thinking to myself that it might be some sort of toxins in the water that is killing the invert that did not get removed by Purigen and that's when I used the carbon in the filter. I used fresh carbon and I put in fresh carbon again week after and now the hermits are ok. I'm even ready to try another cleaner shrimp. <I agree> I think as we do water changes and do other sorts, some how there is a build up of toxins in the water and I realized how valuable carbon is to the water. From now on I'm going to use carbon at least once a month and Purigen at other times. Thank you, Hans <Sounds good. Bob Fenner> Losing crabs Hello Out tank is 110 gallons new a few months.  two power-heads canister filter protein skimmer.  Life consists of currently 1 yellow tang, 4 Chromis, hermit crabs, snails, and a pair of peppermint shrimp over 100 lbs of live rock. I am having a recent crisis.  After a sizable 40-45 % water change we lost an arrow crab  and a few days later both cleaner shrimp.  The cleaner shrimp, after the water change, both shed their shell/skin and one died two days after water change and one three days after, and was unable to swim away from the power-head. I tested the tank before the water change and all levels great.  The PH was a point or so low so I added marine buffer to the new water.<< I would be careful doing this.  Make sure you test the new water before adding it. >> I thought the change in the PH was too much for them because once the water cleared up (cloudy from sand siphoning)<< I wouldn't recommend sand siphoning. I think a simple water change is a better way to go.  Now that you said this, I would suspect an ammonia/nitrite issue to have been the cause of the problems. >> the arrow crab was deceased, but when I tested the tank again the PH was only a half a point different .  After the water change there is now traces of ammonia which never happens usually. What could I have done wrong? << I would recommend only doing a 10% water change.  Remember to never disturb your sand bed.  If you vacuum it or stir it up you can really damage your biological filtration. >> Did I change too much water? Is there anything now i can do what should I do different next time?  How long does the salt water need to be aged? << I let my water mix in a bucket with a powerhead for 24 hours. >> Another problem, we had 11 blue green Chromis now we have 4 they were getting sucked into the power head intake.  I thought this was because they were weak or dead already but one night i saw one trapped and reversed the flow of the power head and caught the Chromis in my hand and he swam away and has been fine ever since.  So I followed some advice to put a sponge in the intake part and it seems to be fine could this cause any problems like reduce the water flow to a detrimental level?  or anything I am not anticipating. << I had this exact same thing happen.  I was losing Chromis and didn't know why, then one day I just happened to be watching when one of them swam by a powerhead and was sucked up.  I now have sponges on all my powerheads, and recommend you do the same. >> Thank you very much for your advice. << Hope that helps. >> <<  Adam B.  >>

Shrimp and Crabs.... Can't Keep Them Alive To whom it may concern: I have a 55 gal. salt tank with live rock, feather dusters, 2 black finned clowns, 2 bar gobies,1 fire Goby, 1 green mandarin, 3 candy striped gobies, 1 palette tang, 1 African flame back angel and 1 cleaner wrasse.  I have no problems with the fish I have had all of them from several months to a 1 1/2 years. <good to hear> The problem I am having is trying to introduce any kind of snail, shrimp or crab.  I have tried acclimating them in several ways, adding a little water over 45 min..<I would test your water for copper> I put them in the tank and they either die immediately or within an hour or so.<huh, doesn't sound good, are these shrimp and crabs healthy when you purchase them?> I just did a 20% water change 3 days ago.  My ph was a little low but everything else is where it should be. Could you tell me if there is something I should be looking for in my water tests that would keep me from being able to keep shrimp, snails or crabs in my tank.<check your water for copper> I have a wet/dry filtration system, 3 powerheads, a protein skimmer that I faithfully maintain.<ok> Any help would be appreciated. <The only 2 things I can think of is there could be copper in your water, or you are getting livestock that aren't healthy, Good Luck, IanB>