Death of Lucy and Ethel

Question
Hi Chris,
I recently bought a betta and 2 emerald green cory cats.  I have a 5 gallon tank, completely cycled.  I introduced all to the new tank slowly and all appeared well for 24 hrs.  Then, both Lucy and Ethel (the catfish) went belly up at about the same time.   I immediately checked all levels...ammonia, nitrate,nitrites were all absent. The pH was 7.0, temp 79 degrees. The betta is doing fine.  Do you have any idea what may have happened?
Thanks,
Becky

Answer
Hi Becky;

Sometimes new fish die and there seems to be no obvious reason for it. I would try again. They may have gone into shock or perhaps they were sick when you got them and you didn't know it. Sometimes stores sell fish that just arrived from the wholesaler. They need a couple of days to make sure they are okay but many stores don't bother to do that. They transport already stressed fish out to a new place again - your house. Look at the same fish in the same tank at the store where yours came from to see how they are doing. If they had trouble too, then you know. Ask them for replacements from a different tank where the cory cats are doing well and are swimming around and eating when they put food in.

Acclimate the new ones by floating the transport bag on top of the tank water for about 15 minutes. Unless your tank water is far different in pH or other chemistry there really is no value to floating any longer than that. It is important that the fish are not in the bags for a total of any more than about one-and-a-half to two hours after the bags are sealed at the store. Unless the fish store puts some pure oxygen in the hags with new fish there isn't enough oxygen to safely sustain them longer than that. Sometimes fish die right away from oxygen deprivation, sometimes it takes them a day or two or even more. During the floating time, add a little tank water to the bag a couple of times. Be sure to reseal it and leave an air bubble in the top. Cory cats breathe like the betta does and need a gulp of air from the top every so often. Once they have been floating for about 15 minutes, gently net them from the bag and release the fish into the tank. Throw away the transport water. The transport water has waste and stress hormones in it that you don't want in your tank.

Good Luck...

At Your Service;
Chris Robbins