I think my fish has ammonia poisoning, he has trouble getting up from the substrate and is very lethargic. When he does get up to swim, he can only do so for short periods and swims in a loopy, erratic motion. The ammonia has been stuck at 0.25 ppm for days now, despite the fact I have done large, daily water changes as well as gravel cleaning the substrate. I have also cleaned the filter in tank water. Also, the pH is 8.2.