HCA: Hermit Crab Association

My previous tank incarnation had both its successes and failures.My plan to prevent mold by not having any organics in contact with the substrate worked. There was no mold in the tank after 8 months (except a small amount under the large cork tunnel, but it hadn't spread anywhere, and food falls under there a lot). It wasn't like before with with submerged wicker baskets where every part of them under the substrate was completely covered in mold and the mold was spreading throughout the sand. The other cork that was in the substrate didn't mold at all.The wicker platforms did get pretty dirty with eco-earth and poos all over. They liked to sit and eat them, so one of them was so eaten up I just threw it. The other one was OK for another go-around. I'd cleaned them a couple of times during the 8-month tank stature as well.The eco-earth/sand mixture did a good job of absorbing the poos. I never had to clean them up.The TropicAire humidifiers did a good job of keeping the air clean and humidity high. The tank never in all 8 months got that musty smell that I always got within a month in my previous tanks.The moonglo (two 25watts) lights provided good head. Up to the low 80's near the top of the tank (top platform), while the bottom stayed in the mid 70's. I also added a fluorescent light that turned on just during the day (using a timer) which added 15w.The crabs dumped the temperature gauge in the water and the inside filled up with water and now it doesn't work anymore, so I need to get a new one of those. I'm not entirely sure the humidity gauge is working right either, because when I had the tank open and empty for cleaning, it still read 60%, and I doubted the house air was that high. So I'm thinking I might need to get another set.And again the major success was with main-tank molts. Nearly every crab in the tank and sharp fresh-molter toenails on them. They all must have molted since the last cleaning, some more than once.I also pulled several crabs from the very bottom of the tank. One was a very fresh molter, but he was done enough to go with the rest of the crabs (didn't need to ISO him). He was pretty pale yet, but hardened and active. I tossed in some extra dried shrimp in the temporary staging grounds to act as bait just incase someone got a hankerin' for some exo. I didn't have any problems at all though. No aggression towards him at all.I want to reiterate again that I think this is the reason I warn against using under-tank heaters. Crabs like to dig all the way down and rest against the bottom glass. If there's a heater there, it could harm them. Also, it causes bricking of sand which they might not be able to dig through.Now for the bad parts.I started getting a bunch of crab deaths with the larger crabs. I lost 6 large and jumboish crabs rather suddenly in the last month. And then the flies started coming around the house, and my wife traced them all to the crabitat. So we definitely knew it was time for full deep-clean TODAY.As I removed the stuff from the tank, I quickly discovered the source of the flies. There was a large dead crabs in the bonsai. It was covered in maggots and mostly eaten away. And of course the maggots grew up to be those flies. The problem was that for the last incarnation, I'd turned the bonsai so the entrance was facing in towards the tank, because that's the only way it fit. So I could never see inside the bonsai to check on the crabs. And I missed his death, probably because he died at the same time as some others, and I noticed that smell and cleaned that up, and then the smell lessened after I removed them, and I didn't realize there was another dead crab yet.I think that the problem was partly I was overdue for a deep-clean. I knew I should do it every 6 months, but I was waiting to save up enough money for 100$ I knew it would cost to get my full filtered-pond setup and other supplies. Plus it was hard to figure out which filter to get, since there's so many and none are exactly what you want. I lost only 1 crab for the first 7 months, and then a bunch in the 8th month. So I definitely know now that 6 months is a prime time for a deep clean.The main cause of the problems I believe though was the water. My attempt at having cycled water without using a filter failed in my opinion. I had waterfalls in each pond to provide circulation and aeration. And I had crushed shells and coral in them for good bacteria to grow on. But that couldn’t stop the Eco-earth beast. Once they started piling that eco-earth up into the ponds, they just wouldn't stay clean. The debris kept getting stuck in the pumps clogging them up so they wouldn't work anymore, hindering the circulation and aeration. And they mucked up the water so dark I doubt any good bacteria could grow. I'd clean it but it would just get full and dirty again. And it would smell like turtle water. It was hard with the large bowls and the fountain to get them fully clean regularly.That's why I have to recommend that you either take one extreme or the other. Either use smaller manageable simple bowls that you completely replace the water every day or two. Or you try what I'm trying this time (well i guess I can't really recommend it until a few months from now assuming it works). I bought 3-stage filters (mechanical/chemical/biological) for each pond, with constant surface aeration from the spout. At the moment the waters are still crystal clear and sparkling. And I also have the ponds up 3/4in above the substrate to minimize them dumping substrate into the ponds. And I have only pure sand on the side of the tank with the ponds to minimize that eco-earth from getting in there and clogging everything up.I also found 3 crabs who had died while molting deep under the substrate. I lost 10 total crabs (3 while molting, 6 on the surface in the last month, and one earlier on).And again I lost a crab! Argh. The last time i lost a large Indo... I really don't know how the heck that happened. I'm hoping it's just a bookkeeping error. This time I lost a teeny E.When I go through the substrate, I take it one handful at a time and sift through it with my fingers as I dump it into a double paper bag. This way I don't miss any buried crabs, and I also get to pull out all the bonsai leaves and stuff that's been dumped into the substrate (including the suction cups for the humidifier tubes which I'd lost some of). After I realized I was missing one, I still went through all the bagged substrate again and still couldn't find him.Oh, another thing I don't recommend. Last time i lined the bottom of the tank with small pebbles. I thought it would aid in water runoff filtering or something. But the crabs just ended up mixing it all in with the substrate with their digging anyway. The problem is that some of the larger sized pebbles are nearly the size of the teeny crab shells. So it's really hard to make sure that every rock was really a rock. So I'm hoping I didn't miss a crab that way. So I didn't do that again this time. I don't think I'd seem him surface for 5+ months, so if he was down there he probably died molting and maybe disintegrated.I'd noticed that the crabs that had died molting were partially disintegrated, I think it's from the eco-earth being more bio-active, there must be bacteria breaking down the matter.Well, I hope you learned something along with me! And I hope my next tank incarnation fares much much better!I've still got 33 crabs left. And all my cavs, rugs, and indos are still with me. And what's really surprising is how much more friendly and outgoing the cavs and indos are now after being in good conditions and molting. They were extremely shy when I first got them, and now they'll come right out in my hand.

Thanks for sharing!Dito on what you said about EE being bio-active. I have lost a crab a while ago and there was nothing left of him when I re-arranged the crabitat and sifted through the substrate, not even the big pincher.

I should say it probably doesn't have to be a complete extreme of a small water dish changed every day.I still advocate always using a big enough bowl that your largest crab can bathe himself (doesn't have to be submerged, just deep enough so that he can dunk his shell in and scoop water through the inside of his shell). But it should be a type of pool that's easy to clean regularly.I used to have shallower (1.5inch) plastic bowls that I could easily clean out every week. I didn't do it every day either, but I did do it every week (wiped clean with paper towels and replenished all the water). And I didn't have a single crab death for 7 months when I did that. So I can say it worked.But then when I upgraded to the larger fountains and their ponds, they were deeply embedded in the substrate (and I don't like to disturbe the substrate since crabs are buried right next to the basins under there), and the fountains themselves are very difficult and time consuming to clean.So my warning is to just be careful of the scale of your water. Make sure it's big enough for self bathing (so that you don't need to stress our your crabs with weekly baths), but make sure it's manageable enough for at least weekly cleanings (changing all water).I'm not an expert on water quality, but I'd read from other posters that water will get an ammonia spike after 1 or 2 days (if organics like food or poos enter the water), which is why the water should technically be changed every day if not filtered.

I just wanted to say thanks for your deep clean posts. They are always so informative, and they often echo my own experiences, although I do not take quite the care with detail that you do.I also wanted to back your 6 month cleaning deadline. I'm on roughly the same deep cleaning schedule as you are, and I have also had significantly more deaths in the past few weeks than is typical with 3 of them being straws during their first molts with me (I got them last Oct). Definitly a lesson learned the hard way.Amber