Haha, it's glad to know someone has had the same obsession.
Thank you for your suggestions! My temperature is in the right range now, but maybe the problem before was because the temperature wasn't high enough. I didn't have a heater in the tank. I've also reduced the filter GPH. I had one small one that actually go stuck to the intake. I immediately pulled the power from the filter and found that he was still alive! He was so mutilated, and I felt so bad for him... I put him in a isolation box inside the tank, and he actually recovered! He's now doing very well
