A pox upon my hermits?

[phuzzykins]

Folks,

I have a 34 gallon Solana which has been up for a little over five weeks now. My tank cycled in about two weeks, and I let it sit for two weeks after that with no critters.

Last week I added my cleanup crew, which consisted of 22 scarlet hermits (I ordered 15, and LiveAquaria overshipped a bit) 6 nassarius snails, and 10 banded trochus snails.

Since then, at least 5 of the hermits have died. No, I'm not just seeing molts, but thanks for asking. I say "at least 5" because that's how many empty shells I can count.

I've seen two of them die in front of me... they crawled out of the shell, lied on their backs, and looked pretty dead, with an occasional twitch. At this point I was actually excited, because it looked to me like they were about to molt. I even set up time lapse video on the first one.

Unfortunately, a couple of hours later, they were both nothing more than buffets for the nassarius snails.

So the questions are:

#1) Is it possible that these are molting crabs being killed and eaten by my snails? I was under the impression that nassarius snails were scavengers rather than predators.

#2) If not, what's likely to be killing the crabs? Does what I describe sound familiar to anyone?

The rest of the livestock (including the remaining crabs) are behaving normally, are very active, and are consuming my various algae blooms like pigs.

My parameters are:

SG: 1.026 (refractometer)
pH: 8.1 (night) 8.2 (day) (ACIII)
Temp: 77-79 (ACIII)
Ammonia: 0 (API)
Nitrite: 0 (API)
Nitrate: 5 or 10 (API)
Phosphate: 0 (API)
Cal: 400 (API)
Alk: 8 dKH (API)
Mag: 1350 (Salifert)

I use Reef Crystals mixed with 0 TDS RO/DI.

I have ~ 40lbs of live rock, and ~ 20lbs of sand.

Thanks in advance,
-Matt

 

[Bonneville08]

Hi,
Your thread is getting a little old and could use a bump anyway.
Everything you listed sounds good, sometimes you don't know why something went south. I would consdier extra shells for your hermits, they do need to move from time to time as they grow.
Hope someone a little smarter than me comes along.

 

[HornetMech242]

Yes, for the hermits you need empty shells. If not they will kill each other for shells. I came home once and one was out of his shell and on top of another. I knocked him off and put an empty shell by him and he crawled right in. So the empty shells will do some good.

 

[phuzzykins]

I did add a few empty shells at the same time as the hermits - nobody has shown any interest in them. A couple of the emptied shells have new owners now, but the crabs inside them were already dead.

So far I haven't seen any aggression between the crabs.

Since this is a new tank without much of a food source other than algae, and the nassarius snails are carnivores, I've also been feeding a small amount of formula one pellet. Hopefully that's cut down on any chances of aggression from them.

 

[WaterKeeper]

That's quite a crowd of hermits and the are not all that peaceful. It very possibly predation but I'd also check you current ammonia levels being you have a newly set-up tank.

Although they were always touted as part of the initial cleanup crew, hermits can play havoc with LS critters and I no longer recommend they be added to a tank. The snails are fine however and will live far longer if hermits are absent.

 

[phuzzykins]

Thanks, Tom. I do agree that the stocking level was too high - as I mentioned, I got significantly more hermits shipped than I ordered, and several of them were significantly larger than the size that was listed.

I checked my ammonia level the day after adding the cleanup crew, and twice since then. Undetectable all three times. I added a bag of carbon to handle anything I'm not testing for.

I did have quite a pronounced ammonia spike during the cycle, so I'm confident that my testing methodology is good.

At this point, it seems there's not much left to do other than hope the population stabilizes.

In the meantime, here's some 30x time lapse video of snails doing what snails do. Please enjoy my hair algae, bryopsis, and copious detritus as well. http://www.youtube.com/watch?v=s29lXgvE2lE

Thanks,
-Matt

 

[avel]

What is your tank temperature?

 

[phuzzykins]

avel,

The tank temperature is maintained between 77 and 79, with a target of 77.9. The ACIII graphs don't show any spikes or dips outside of that.

Cheers,
-Matt

 

[EllieSuz]

Ok, here's the good news. Of all the hermits, the Scarlets are the most benign, in my opinion. I'd find homes for a bunch of them, however. I have three in my 40 gallon and that's about right.