plz help! My Betta Stephen who i've had for about 2.5 months has been lethargic for about 2 weeks now and at first I got the water tested and I had a nitrite problem but I fixed that within a few days and now the tests show no water parameter problems at all but no improvement for him. He has been staying at the bottom and struggling to get up for air and then going right back down again. his water temperature is always consistent at 79-81 degrees, and I have done 3 water changes in the last two weeks and tried rinsing the filter once. Some people have said it could be swim bladder disorder, but he hasn't eaten properly in like a week and he's not bloated and two days ago he pooped white meaning it was only mucus because there was no food inside him. he seems hungry, but when I try to feed him he either ignores it or tries to eat it but spits it out a minute later even though it's what he's always eaten before. He was in a 10 gallon with 2 minnows but a separator in between and the minnows have since been moved and I just now moved him into quarantine in a glass bowl with a thermometer, a piece of almond leaf, and his moss ball. He keeps looking worse and more tired.... PLEASE HELP!!!