That's odd. It could just be stress of coming into a new habitat. He's aclimated, so it couldn't be from a change in anything as he should be used to your parameters now. I really don't know why your fish would just drop off like that unless they are old, and died of natural causes. One good question is how much salt are you using? This could be a problem if you are using too much. Also what is the temperature of your tank?

You should never treat for things that are not occuring. The only treatment that is safe to use on possibly ill fish would be mela or pima fix and stress coat or zyme. Others could do more damage than good.

He should start to come around. I don't see any problems from your first post that would indicate a disease/illness. Let me know about the salt, and temperature, and we'll go from there.
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Phishie
Site Coordinator

"An ounce of prevention is worth a pound of cure."