I have a fishing pond back of my house stocked with cat fish, bream and large mouth bass. I had over 50 cat fish die that were about 8 pounds. I still have enough and they give me a battle. The bream are bigger than your hand. Lots of good fishing. Lots of friends bring their kids and grand kids out to fish.
I have some nice size catfish about 7 to 9 pounds and starting this past spring I have lost about 52 of these fish. When I think it is all over I will lose one more. I went about 2 weeks this time and maybe more before losing another cat fish. The smaller catfish are not bothered just the larger ones. The larger cat fish when harvested have a very firm meat in fact it is tough. We tried different methods of cooking and they were still tough. At least 2 1/2 acres , aerated with a depth of about 6 feet. The fish eat very good from 2 automatic feeders.
No idea.. I do know they have some pond forums that deal with building ponds, etc. One of those type place may have an idea of what is causing the problem. My first thought was oxygen levels, but you said it was aerated and would think the bass and gills would be more susceptible to that then the cats. Good luck let us know what you find out.
I did go on the pond boss forum and they had a few ideas. Just lately the catfish dieing and floating has almost dropped to zero. I still plan on getting some pictures to post, it is all nice but not terribly outstanding. I say it is the best I have ever had as I did not have anything similar. I do not use the building like I should.
deaner you have a pm
GET IN, SIT DOWN, HOLD ON, AND BE VEWY VEWY QUITE!!!!!
may be bad fish food