I have a 10 gallon tank with around 7.2 ph, no nitrates or ammonia present (recently primed and checked), consistent water changes 25-30% once a week, and temp at 76 degrees. 4 guppies (1 female, 3 male which I know is not ideal but the females the tank bully which helps her) and one dalmatian molly. I noticed that one of my male guppies (black yingyang) in particular has gotten some fin rot, which might have spread to my other white ying yang guppy but not as bad. my baby cobra guppy seems fine, but my only female yellow tailed guppy is losing some serious color on her tail. Was wondering if this is an early sign of fin rot and some advice on what to do. Since suspecting it, I’ve changed around 30% of the water and have been putting melafix in once or twice a day. Any help diagnosing would be great.