I feel like a terrible fish mommy. All three of my betta fish have black gills, and from what I have read it's bad, but none of them have trouble breathing and swim just fine. Any ideas? I've been having a challenge keeping the tanks clean with limited money and living in a pretty humid basement. I do have a whisper filter in each tank, and all three are 1.5 gallons. As of this weekend I'm buying new filters and a gravel vacuum. I am currently treating them for fin rot and will be doing water changes in a few more days. Any tips for keeping the tank clean and happy fish?