Need help, fish died

[jang]

I have a 5 gallon nano tank which has been up and running for about 8 weeks. I had 5 blue legged crab, 2 peppermint shrimp, 2 snails, 1 Narcissus and 1 Turbo and 2 blue damsels. I'd had the damsels for about 1 week. They seemed to eat well and looked healthy.
I bought a 29 gallon yesterday as I planned on moving everything over to it once it is fully cycled.
Yesterday morning, I got up and 1 of the damsels was dead and the second was dead this morning. In fact, they had turned white and the crabs were having them for breakfast.
I've checked and re-checked everything and can't figure out what went wrong. They didn't have any ick or disease that I could see and seemed fine the night before. Also, one of the shrimp is gone.
My paremeters are as of this morning:
PH 8.2
Nitrite 0
Ammonia 0
Nitrate <10
Salinity 1.021
temp 80
Does anyone have any ideas? I'm at a loss. Thanks much.

 

[some1fishy]

dumb response: has you tank cycled? Any live rock in there?
Parameters look fine... power outage? Do you use tap water to change or start your tank? stray voltage maybe, but damsels are pretty hardy. Your inverts are okay? could be just the fish....
hope the change over bodes well.

 

[sagxman]

Sounds a bit overstocked to me. I wouldn't put more than one fish in a 5gal. Maybe one shirp and about 5 cleaners. How long was all that livestock in your tank? Some people aren't even through the cycle in 8 weeks.

 

[jang]

The tank had fully cycled and I realize I had too many fish in there which is why I bought the larger tank. Actually, the fish hadn't been there a week yet.
I do have about 10 lbs of LR and LS. I use RO water for top offs and re-fills.
I'm really confused.

 

[sagxman]

If your tank had fully cycled and you put that much in about a week ago, it could have easily been too much bioload for your system. Levels may seem fine now, but I bet they shot up for a bit.