Fish Die, Snails and Crabs Fine

[toobs]

I have a 2 month old 55gal. tank. I put six fish in it when it was a month old. The fish looked o.k. for a week or so then they died. There was no signs of Ick, they just shook to death within a day of showing any symptoms. I've had snails in there the whole time and they are doing well. I recently tried another damsel and he died within the first day in the tank. So I then got a couple crabs and they seem to be fine. I test my water and all parameters are perfect. I can not figure out what could be wrong and I don't want to kill anymore fish? please Help.

 

[ocellaris_keeper]

once one dies the ammonia spikes. If your biofilter can't adjust and the hermits don't eat the thing before the spike, it causes a serious chain reaction.
the snails and hermits can survive durign a quick ammonia spike.

 

[dathem]

Hello,
You mentioned the fish shock till they died. That to me sounds like the fish were not real healthy when you bought them and they shock and stress of bringing them home was too much possibly. Did you slowly over a hour or longer let the bags floot in your tank and add very small amounts of your water to the bags over that hour? What is the temp of your tank water, did the water in the bags get cold by the time your reached home? Please give the specifics of your tank. Do you have any live rock or live sand? We need possibly more info to help you.

 

[marine fanatic]

Just a thought here but....the tank is 2 months old? Perhaps the cycle was at the ammonia spike stage and maybe in combination of unhealthy fish caused the deaths???? I lost 2 damsels in a 24 hour period right at the ammonia spike stage even though my hrmits and emeralds did fine. I am no expert here but in my own experience, the inverts I have are far more resistant to spikes than my fish, even the damsels.
Hope it helps