sick black fish

I’ve had this molly for around 8 months now and his mouth is incredibly swollen. I’ve tried different treatments including tonic salt and fungal medication with no luck, it only seems to be increasing in size. I don’t think it’s fungal as it doesn’t look fluffy, just very swollen. The tank he...

I had a sick tank 55 gal. Jacks started to turn black and dying, 5 died. I saved 3 by rehoming them. Amonia was high so i assumed it was an ammonia problem. Got ammonia down, nitrates are high but coming down. Getting the levels right in the tank.... So i was advised that the tank was...