Hi. (This is all the info Ik and have. Can't supply much more till I am home) I'm away from home on vacation and so had my dad feeding my fish. Everything was fine water was crystal clear. It was all fine. My dad came here to vacation with us. On Friday the water was still clear but he just got home tonight (Sunday). And yes we had someone feed the fish Saturday but he just got home and apparently the water looks super green. Any ideas as to what this could be? I told him try rinsing off the filter cartridge (it's a Top fin Power 20) and I was hoping that would work? I also have a Plus Plex 400 I believe is the other one? Not too sure. I can check if needed. It's a 20 high with a juvenile Female Lavender Mbuna (yes she will be moved Ik the tank is too small). Thanks.