Please visit our Sponsors
FAQs about Marine Scavenger Losses/Troubleshooting

Related FAQs: Marine Scavengers 1, Marine Scavengers 2, Marine Scavengers 3, Sand Sifters, Sea CucumbersShrimp Gobies, Sifter Gobies Marine Algae EatersHermit Crabs, & FAQs on Scavenger: Rationale, CompatibilitySpecimen Selection, Clean Up "Crews"Worms As  Scavengers, Snail Scavengers, Shrimp Scavengers, Hermit Scavengers, Crab Scavengers, Cucumber Scavengers, Sea Urchin Scavengers, Serpent Star Scavengers, Seastar Scavengers, Fish/Groups as Scavengers,

Related Articles: Scavengers/Clean-up Crews for Marine Aquariums, by Bob Fenner, Some Fishes Are Good For More Than Just Looking At, by James Fatherree, Genus Valenciennea GobiesHermit Crabs,  


My Sand Dwellers Keep Dying Hi Bob, <Hello Darrin> I have a problem that I just cant seem to figure out. Everything that seems to touch the substrate/sand in my tank seems to die. I have a Tang, Blenny, 4 Mithrax Crabs and 2 hermit crabs that have been thriving in my tank for the past 3 months but everything else just keeps on dying and I don't know why. I have lost one anemone (which was the first death), 6 starfish, 4 sea cucumbers, 4 Astrea snails and one abalone most of which died within 2 days of being introduced to my tank (I did not enter all of them at once). My tank specs are as follows: <Mmm, some good clues here> 60 gal Aqua system w/built in wet/dry (bio media removed) Remora Pro plus protein skimmer Fluval 404 canister filter (bio media removed) 90lbs live Fiji rock approximately 4" of live sand (purchased from LFS not sure or origin) Excellent lighting system Nitrate, Nitrite, PH, ammonia, alkalinity and water salinity all have normal readings but I just cant seem to figure out what is causing the deaths. <Could be a lack of circulation/dissolved oxygen... or perhaps a biological source... something growing in/on the surface substrate> I do have an algae problem though. There seems to be what looks like little greenish pellets that appear on my substrate that I have to clean constantly. These "pellets" look similar to the rabbit food one can find in pet stores. <I see> I'm sure I'm acclimating my new inhabitants properly by immersing the bags in my tank and every 10 to 15 minutes I pour some of the water they were shipped in out and replace with my tank water until eventually, they are in 75% to 100% of my tank water before they are released to the tank. <Would be better to utilize another system for quarantine/acclimation... newcomers may be getting beat up and already in bad shape from being new> What do you think are causing all of my deaths? I'm very frustrated and am considering stripping the tank down and starting all over again. Please help. Darrin <I concur with your suggestion... at the least I encourage you to siphon out (with a large diameter hose) the existing substrate and rinse/wash it thoroughly (with fresh water)... and replace it in the system once clean... you should have enough beneficial microbes in the tank to keep biological filtration going... Do make up enough stored new seawater to replace that which you remove. Bob Fenner>

Clean up crew Thanks for the help with the FW dip.  Now I have another.  The tank I purchased was from an LFS.  It is a 25 gallon with an IFS.  I already read the article pertaining to small bubbles in the tank on a previous tip you advised another, but my question is should I downgrade my water pump, is it too strong, it's a RIO 1400? <It's rated for 375 gph right? I'm sorry but I don't have all the info that I need. Is this a pump used as a powerhead, submerged in the display tank? If yes then I suspect it may be too powerful. Is it a pump that is moving water from a sump, through the plumbing, returning to the tank? If yes then the pump may or may not be too strong. Does the tank look like a whirl pool or is there a brisk but reasonable current? Can the fish in a seemingly normal fashion? If yes the no worries>   Another question, I may be freaking out with my  Angler and all, but I really don't want to lose it (Gus). <Me neither> I have two other fish in the tank and they have no problems at all.  One is a 4 stripe damsel <This guy will be history soon. The scorpion will eat him...very soon> and the other is a scorpion.  Both have been in the tank for over three months with no troubling signs. <In the long term this tank is small for a scorpion and/or angler> My problem may be with the amount of cleaners in my tank.  I have about ten Scarlets, eight blue legs, two Mithrax, one sand sifter star, one fighting conch, and a serpent star plus a minimum of 12 assorted types of snails (Astrea and Trochus with at least two baby snails somewhere on the sand that I have seen).  Is that too much? <Seems like a lot but that alone won't cause a disease problem...if that's what you are asking. In fact, if the little critters can't find enough to eat they will die off soon any way> Could that be the case, too many critters, too little Oxygen? <Not IMO> Thanks, <You're welcome1 David Dowless> Jamie

Dying cleanup crew I have a 45 gal. tank and recently I purchased a cleaning crew to keep the tank active yet ready for fish. Lately I noticed that most of the  of the cleaning crew is dying. I have live rock, a clown with an anemone, some flower anemone, urchin, 1coral banded shrimp some snails, crabs. most are still alive but the Nudibranch died. <It would be more of a surprise if the Nudibranch survived. These creatures have a miserable record in aquaria. Replacing it would be a waste of time and money> I supplement with strontium, calcium and iodide, and I also use ChromaPlex, but they are dying off. I have a small glass anemone I noticed in the tank, could it be that they are eating the anemone and poisoning themselves? <I don't see this as a possibility.  What are your water parameters (ammonia, nitrite, nitrate, pH, and salinity)? Did you acclimate these critters over an extended period of time? A drastic change in salinity will kill these animals quite easily. David Dowless>

- Snails and Hermit Crabs Dying - Hi: <Hi, JasonC here...> I have had my system up and running for almost a year now with no major problems. However within the last 2 months my snails and hermit crabs have been dying. I have enough algae growing on the Live Rock to keep them busy. My Ammonia and Nitrates are zero and the PH is 8.4. Any ideas on what could be wrong? <Probably nothing - most likely a form of natural selection at work, and none of these live forever... I wouldn't be too concerned.> Thanks, Aram <Cheers, J -- >

- Re: Snails and Hermit Crabs Dying - Hi Jason: <Hello again...> Thanks for getting back to me. I checked my Ca level last night and it's down to 200, Could this be causing the dye off. <I doubt it.> Also my ALK is really high about 800 mg/l. <Egads, that is high, and would explain the low calcium.> I add 2 teaspoons of KENT Super Buffer once a week to maintain my PH, could this be a problem also. <Potentially... could be your water is already pretty 'hard' and doesn't need supplementation - stop adding the Kent product and test your source water.> Thanks, Aram <Cheers, J -- >

Cleaning Crew Run-Down Ryan, thanks for taking the time to answer my question. <surely!>  I have read the FAQs re: sand sifters and decided against the sand sifting star. <You'll be glad, believe me.> This time around I would like to let the animals do most of the clean up work.  When I stated in the previous email "an assortment of snails", I was thinking about Nassarius, Cerith, Bumble Bee, Turbo, Trochus, and Astrea snails.  <Nice assortment, but you may starve this many snails without a heck of a lot of algae.  Turbo and Trochus seem to be the most productive in my tanks.  My bumblebees are a bunch of freeloaders!> I've read that these guys should help with the detritus and algae. <Yes, to an extent.>  Just how many do I need for a 125g tank?  <25-35 max.  Start with 15, add them as your tank matures.> Also, I've had a problem with Blue Leg Hermits eating my Astrea snails (not for their shells), and don't want this type of hermit again.  <Most hermits are opportunistic by nature.> My Scarlet reefers have never bothered any of my snails, and I like them a lot. Would about 50 of these guys be sufficient or should there be a mix of hermit species? <50 is way too many.  Try 20 to start, and see how this works.>  I was also thinking of a sleeper goby, but don't want to have him starve. <Skip it.  Not sure what kind of aquatic life you plan on keeping, but many fishes will take care of algae growth better than a sleeper goby.>  What would you suggest re: a clean up crew for a 125g?  <My "dream team," first off, would include a refugium.  Prevent the algae from growing by diminishing the available nutrients.  The snails and hermits sounds fine.  Look into opisthobranchs, commonly known as Sea Bunnies.  A great algae eater for bigger setups.  Also consider Cypraea annulus.  What I've found with grazers is that diversity is the key.  Each of these animals occupies a different niche in nature, and therefore in your tank.  The more diversity you add you cleanup crew, the less you'll have to intervene.  Talk to you soon! Ryan> Thanks again for your help and patience with my questions.

My hermits are becoming reclusive!  07/23/03 <Hi Chris, PF here with you tonight> I picked up 9 "zebra hermits" (although I swear they're blue-legged hermits by visual identification) at the LFS for some hair algae control, as well as 4 Astrea snails. For the first few days, the hermits chewed away happily at the algae, and tended to congregate in small meetings. It's been a week, and all the hermits have seemed to crawl into crevices in the LR. They all have their antennae (?) wiggling about on their faces, but they remain in there at leisure. Are these creatures nocturnal? I'm somehow doubting that. I know any aquarium won't live up to what my ideal 'bustling with life' scene might look like, but I was hoping for a little more action out of these guys. Should I be looking towards water quality issues? Everyone deciding to molt simultaneously?  The Astreas seem to be faring well, happily chewing away at the algae. 3 seem to be doing fine. The last one is quite lethargic, moving at a snail's pace, as it were.. I will be doing ammonia/nitrate tests in a few minutes.  pH is hovering at 8.2; s.g. at 1.024; temp ~82F. P.S. Since I last wrote to WWM a couple of months ago, my so-called "hard cure" has long since become quite rewarding, and I could not imagine ever wanting to buy "fully cured" LR! Tons of creatures lurk in the depths of my tank, including strange translucent tentacles (approx 1mm in diameter) that shoot out of tiny holes in the LR and suck in detritus with their vacuum-cleaner like tips (any ideas on what that might be btw)?  Thank you for providing this wonderful service WWM crew!  Enjoying this hobby, even if I am making all the beginner mistakes one at a time, - Chris <Well Chris, they could be blue legs in zebra snail shells. A rose by any other name... As for their behavior, remember, they don't read the same books we do. I've certainly seen my animals doing things that they're not supposed.  The critters on the rocks, are probably some sort of worm, maybe the spaghetti worm, check here for more: http:// www.wetwebmedia.com/polychaetes.htm   Mistakes, well, I try not to make beginner mistakes myself, but all new ones. ; ) At least it was one at a time, and not all at once.  Have a nice night, PF>

Cleaning crew aggression and not so mysterious deaths - 10/10/03 Hi guys, my question is regarding the compatibility of some of my invertebrates. <Hi. Paul in today. Sorry for the delay>  The animals in question are 3 peppermint shrimp, 1 coral banded shrimp, 2 Brittlestars, 1 sally lightfoot crab, 20 blue legs hermits, 20 scarlet hermits, 3 emerald crabs, 1 porcelain crab, 1 orange Linckia starfish, and 20 turbo snails. <That is waaaaaayyyyyyyy too many inverts in such a small tank. My goodness!>  I have a 29 gallon tank <unbelievable......> and feed small amounts of brine shrimp and flake food 3 times a day. <Do you have fish as well?? That is a lot of food>  The problem is that it seems one of these guys is killing off the others one by one almost daily. <I am not surprised one bit. Firstly, Do you check water quality? Secondly, these animals are mostly if not all omnivorous. They are opportunists for sure. They will eat most anything. They usually come to you lean and mean so that they may "go to town" in your tank and prove their worth to you. There is no way this tank will support 2 brittle stars (forget the Linckia) the shrimp are in trouble (brittle stars have been linked to their disappearance at times) Crabs are fairly aggressive eaters and turn to other "things" when they feel they are not getting enough of what they like. Hermits will eat each other when in cramped quarters even with enough food, and there could not be enough algal matter to support all of those snails let alone all of the others who will rely on it for sustenance. Lastly, I wouldn't be surprised if you are having water chemistry issues. Feeding three times a day, plus the very large bio load all in a 29 gallon tank. Did these all come in at one time? (I will assume they did)> 3 days ago it was one of the emerald crabs, then the sally lightfoot, then a Brittlestar.  The Brittlestar had the most noticeable damage thus far. <Again, I am not surprised>  I awoke to find it missing two legs and having lacerations across it's central disk from where one of the legs was attached.<Again, I will assume that these came in a package deal. Which may mean that you acclimated them and added them all at once within 24 hours or so. How long after their addition did you notice the issues being described above??>  Once I got back from lunch it was even more injured than before.  I haven't seen the porcelain crab for a while either. <Could be a goner>  This has just started in the past couple of days <How long after they were introduced?> - who do you think is the culprit <I am leaning towards you, mate> and what can I do to stop my animals from getting killed? <Well.......................do research you inhabitants and their environmental needs before purchasing. Seek advice before change, then make the best decision. A lot can be found on various websites, books, and clubs. I am sorry for my lack of tact here, but sometimes and aquarist needs to be saved from oneself as well as the animals in his charge. I can't stress enough to read about your animals before purchase. There is usually some detail as to how many per gallon or per tank size listed and in some cases even info for compatibility. If there isn't, find a reference for it, or ask someone. My only advice on this manner is to maintain water quality, hand feed when possible, and either give away, sell (maybe), or move (to another tank) some of your dudes. Under normal circumstances these animals sometimes have some mortality in shipment stress (nothing you can do about it) but a lot of mortality comes from acclimation. We have much on our site (not only on a per animal basis but also an actual general acclimation site as well. Quarantine is another good idea. You might even already do this, I don't know. Read through our site a bit. There is hope for you and your animals. The ever winding path of learning! Let me know if there is anything more I can do -Paul>  Thanks, James

Clean Up Crews Hello again Bob. Thanks to your quick response on my last question. I recently purchased a 75 gallon clean-up crew (90 different snails & hermits) for my 75 gallon tank from Flying Fish. I was amazed at how quickly and efficiently they cleaned up the tank. They just had a feast, which brings me to my concern. Now that they have had their turkey dinner, will there be enough food available for them to continue to survive? I understand algae will continue to grow in my tank, but is there enough for the many creatures. Is there something additional I should be feeding them? <Only experience can tell here... this is a large number of "cleaner uppers" for a 75 gallon system... if it starts to look a bit threadbare, I might try adding some strips of Nori algae first... removing some of the animals if they are obviously w/o much to scavenge. Bob Fenner>

Re: Clean Up Crews Thanks for the advice! Should the snails/hermits be removed if they die? <Yes... if you can tell they are dead...> Will they cause ammonia spikes? <Possibly... if there are too many, too soon, in too small a volume, inadequate filtration/circulation...> How do you tell if they are dead, since they don't move all the time and can hide in shell?  <Usually can't... unless outright "hanging out" from shells... > I also thought that was a lot of creatures, but trusted flying fish who I have been happy with. Package below BN-30202 "Classic" Cleanup"¢ Crew 75 Gallons 15 Scarlet Reef Hermits 30 Turbo / Margarita Snails (mix determined by availability) 45 Red Leg / Left-Handed Hermits (mix determined by availability) Package deal saves you $76 March Special - 10% off + Free Emerald Crab <Yes, I know about these package deals... still consider this a bunch myself... Bob Fenner>

Gammarus attacking snails 8/19/04 Dear reefers,  My quarantine tank has been "idle" for some time  -  i.e. no new acquisitions during the summer holiday period - and a large population of small amphipods has developed, presumably a Gammarus species. While observing the inhabitants ( I use surgeon's goggles and can see small creatures well) I noticed 2 Gammarus shrimps "worrying" a Cerith snail. They were picking at its flesh, and at one point extended a "string" of attached flesh.  <Hmmm... These critters are often carnivorous on dead things, but few are predatory.> The snail did not seem too concerned and carried on feeding, but I do not think that the attention was doing the snail any good. I have had a couple of snail deaths in this tank over the last 2 months, and in each case there were Gammarus in the shell when I removed it. Is it my imagination or do Gammarus nibble at snail flesh if hungry? <As above, it is no surprise that the 'pods would eat an already dead animal, but it is very unlikely that they killed it.  The shells also make an outstanding home! I suspect that if they were doing harm to the snail, it would retract into it's shell.  A simple solution that will prevent this problem (if it is a problem) is to add some food for the 'pods.  Some fish food or crumbles of meaty sea food will work very well.> Would it be a good idea to add a Rainford's Goby to the quarantine tank - no fish in there otherwise - to reduce the Gammarus population, or will the Rainford's eat my baby Cerith ( Dove ) snails which breed in the tank? The baby snails range from only 2 millimetres long. The adults are only 1/2 inch long.  <A Scooter blenny, Mandarin fish or six line wrasse are all much better choices to reduce the 'pod population  the scooter and mandarin are low risk to your snails, the wrasse is moderate risk.> Best wishes, and thank you for all your help in establishing a successful skimmerless tank - a year old now. Eric Brightwell FZS  <Best Regards!  Adam>

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: