Mini Brittle Star Mass Die Off

[daniella3d]

Do you have sand? is it old sand or new sand?

I have used epsom salt before to try to cure a popeye on my trigger fish and I went a bit overboard and put quite a bit directly to my nano tank and it did not kill any starfish that I could see...nothing seamed to be affected from what I remember.

I would be more worried of some anaerobic area in the sand if there is sand and if the old sand was kept and moved.

Beside that, they are pretty tough little guys so this is not a good sign. I never saw one die unless it was killed by a fish or by mistake while handling frag. I even put a few in peroxyde dip without realizing it and after a few seconds in the dip they went right back into the tank and survived.

I would recommand also doing a copper test, just in case.

Do you use a well calibrated refractometer to mesure salinity or an hydrometer?

Originally Posted by ScubaSteve

The tank was swapped 1.5 months ago to the new system. Something went weird in the transfer and it cycled. Hard. I lost all but a handful of my SPS (expensive frags went to a friend's tank). So I don't know if these weird happenings are part of the ensuing aftermath of the tank swap or if there is something seriously bad about to happen. I'm waiting for a small cycle if these brittle stars are dead.

[ScubaSteve]

I use the refractometer in my lab to do checks and I've also calibrated my swing arm hydrometer against the lab refractometer (repeatability is excellent) for doing quick check ups. The lab refractometer is calibrated daily.

I did a copper test earlier in the week with my HPLC. Aside from a little signal noise, it was undetectable. I actually use the HPLC for an elemental analysis to save on having a bunch of test kits. Waaaaay cheaper. Well, way cheaper when you have free unlimited access to a $100K HPLC

My new sand bed is a mix of new sand (actually old sand that was dried out and rinsed like no tomorrow) and a few scoops of sand from the old tank to help seed it. I can say with almost certainly that there is no excess of anaerobic activity. I have other critters that are far more sensitive to H2S and they are happy as clams (er... sorry for the pun).

Magnesium sulphate is used as a muscle relaxant for snails to anesthetize them before dissection, I don't know if it has the same effect on brittle stars though. I don't think this is the cause though because my strawberry top snail was acting funny before this.

[Delphinus]

I don't know if it's the cause but 1.028 is way too high. That's something I've never really understood. Mg obviously affects SG but so do a lot of things so 1.025 from a salt mix and then whatever Mg added to bring Mg in check to that brings up SG, but if it was say 1.025 plus Mg to get 1.028 is that equivalent to simply mixing more salt to get 1.028? More than likely not. So I can't even speculate if that's the cause here. Maybe??

The few things I can think of on top of what you have already looked for:

- copper (take a sample to an LFS maybe and ask them to do it)
- temperature swing
- O2 deprivation (likely not -- usually fish will go first if that were the case -- but, something to think about nonetheless)
- some other kind of toxicity to the tank. Detergent, soap, ..

Or it could just be a small enough ammonia cycle and the test kit just didn't catch it (it happens)..

Good luck sorting it out!!

[Xenoch88]

ANOTHER CHEMIST!!! YAY!!!!!

[ScubaSteve]

Originally Posted by Xenoch88

ANOTHER CHEMIST!!! YAY!!!!!

Sssshhhhhh! Those aren't the things you admit in public Actually, chemical engineer, but close enough.

[AquaticFinatic]

I just set my tank up around a month ago and did a small amount of rock transfer from my holding tank. After the rock was in I started to notice my brittle stars coming out the rock and falling to the sand dead. I had done a cycle and all was normal. The only thing that I think it might have been was when I glued my plumbing together I didn't leave it long enough to dry before I put water through them. Have you done anything like this?