I'm guessing I have about a 50/50 mix of male and females. Although only about 15 or 20 percent clearly look like males. Probably because they are too young yet. My nitrites were at zero. I changed all of the old water from the pool into the new pool and all of the filters. I washed the new liner with dawn and rinsed it but I could still smell a little plastic though it may have been coming from the outside, which I didn't wash. I don't think water quality was the problem. The belly of one of them was a little swollen and I wondered if she was full of eggs but she wasn't. The tail was a little chewed up on the other one and it's scales were a little chewed. I didn't pay attention to behind the gill area but now that you mention it I think it was a little lighter color and may have been chewed up. I could see the big males were clearly doing the aggression. I have seen them kissing before but yesterday they were going nuts. I am convinced it has to do with temperature. The pond is down to 75 degrees this morning but was almost 90 when all the aggression was going on and the two fish died. That's quite a fluctuation of temperature. I think that and the fact that there's not enough places for the small fish to hide is also a problem.
I'm planning on buying some 2 and 3 inch pvc pipe and cutting it into 8 inch lengths. This will give all the smaller fish a place to hide. The big fish have taken the flower pots and chase fish as they swim by. Is there anything else I can do to lower aggression? I am considering shade cloth to lower the temperature. But only as a last resort. I'm also trying to think of something to throw in the water to give them more places to hide. 3 inch pvc isn't cheap and it seems like such a waste to cut up good pipe. Metal would probably be bad for the water or I would start saving tin cans. What about drain pipe? It's 4 inches but it's cheap. What about tree branches? Would that mess up water quality?
