Cleaning Crew Mortality

[trippclark]

After many months of what I must admit was neglect of my tank, about a month ago I purchased a 20-55 Reef Package from SWF.com and a percula and a yellow tang. The package included: 20 Scarlet Reef Hermits, 20 Blueleg Hermits, 20 Turbo/Astrea Snails, 1 Sally Lightfoot, 2 Brittle Stars, 1 Coral Banded Shrimp, 3 Emerald Crabs. The cleanup crew was needed because undesirable algae had gotten out of hand. Before this addition and still, my water quality appears quite good. Specific gravity is 1.022 – 1.023. Ph is at 8.3. Amonia and Nitrite are at 0. Nitrate is <= 0.2. Calcium is lower than desired at about 180. Temp is at 79 – 80 degrees. Before adding the crew and 2 fish, the only fish in the tank was a Royal Gramma that I had had for over 3 years.
All new inhabitants were acclimated with a slow drip as recommended by SWF.com. Both new fish are doing fine. The Royal Gramma died last week, but I attribute that to stress from the new tankmates (he started hiding more immediately after new fish were introduced) and maybe even old age. What seems odd to me is the unusually high mortality rate among the cleanup crew. In the one month since introduction, all 3 Emerald crabs have died as has the Sally Lightfoot. I am down to 14 snails (something seems to be eating them – the crabs?). Both stars are doing fine, although one lost about half of one tentacle over the weekend – unknown cause or culprit. What is especially puzzling is the hermits. It is tough to get a count because they are all in, under, and around the liverock, but having started at 40 total (20 each), the best inventory that I can take is about 15 blue legs and only 1 or maybe 2 scarlets. This seems to be an extraordinarily high mortality rate with my crabs, with the main survivors being the blue legs. Are these guys assassins!? Any ideas on what might cause such a horrible survival rate in the crew? What am I missing?
Tripp

 

[reefer44]

The blue leg hermits are propably eating the snails and stealing the shells....also mine seem to kill the scarlets sometimes and steal there shells...also they could be starving to death but that doesn't seem like to big of a clean up crew

 

[trippclark]

Thanks. Yes, I am inclined to think that the blue legs are killing the snails and maybe the scarlet hermits. The only think that dissuades me from this conclusion is the deaths of all three emerald crabs and the sally lightfoot. I can't imagine a little blue leg hermit killing one of these much larger crabs; and so I wonder what is causing them to die and if that same thing may be contributing to the scarlet hermit deaths. Whatever is going on; the blue legs are the only crabs doing well.

 

[bdhough]

Well. I personally think you had way to many hermits to begin with. While they are tiny they will war with eachother to a certain extent. I've heard that you only want one hermit of either type per 5 gallons. Hermits will eat snails to get their shells. If you didn't have alot of extras im sure they started killing. As far as the emeralds go i dont know. I bought one and a week later he just died. He moved around alot and was eating off of the rock so i don't know. Sound like yours? Your calcium may be a slight factor. There doesn't seem to be enough in the water for all of them. They do use the calcium to create the hard shells they all molt every now and again. Snails create their own shells. It may just be you added way to many inverts at once. In my tanks i've found that half the tank size should be the hermit population while the rest if filled out with a variety of snails, shrimp, crabs, etc....

 

[jarvis]

You said your Ca is at 180. It takes alot of neglect for it to drop that low without suplementing anything at all. Not saying that that is the culprit for the dieoff, But without doing waterchanges trace elements are depleted. You cant expect things to thrive in tankwater that has been neglected. Have you been doing any water changes?

 

[trippclark]

You are correct. After many months of all to infrequent water changes I am back on a steady routine and trying to raise back up Ca and trace elements. Ca has come up 30 from 150 about 3 weeks ago. I don't want to spike things too quickly, so I am changing 4-5 gallons once or twice weekly until Ca gets back up. That is the present plan anyway.

 

[hondo]

No question the blues will take out your snail population. the scarlets are probably down under and around your rocks and not readily visible. I know that's where mine always are as the tank has 25 in it but I'm lucky if I can see 3 unless I lift out some LR and there they are under the rock and along the crevices eating the detrious.