Hi, my husband got an aquarium for Christmas, but after discovering 2 surprise fry while cleaning it, it started to become my new hobby. I learned how to sex the fish, and realized we’d been given 3 male and 1 female. The female was unfortunately sucked up into the filter intake (as we later realized, the box had been opened, and it was missing instructions and the cover for the filter intake). I wanted to get more female, but Petsmart didn’t have any at the time. So—I ordered some blue MM Platy and a guppy pair from a website. 3 of the Platy that arrived were female, and 3 male. After a day, I began to notice that the male Platy didn’t seem to look very healthy, and were having trouble swimming. The tiny “peaceful” male guppy was chasing them relentlessly, and it seems some bottom fins were even torn off, so I separated the aggressor. I noticed one fish had two white patches on his tail fin, and when I looked at him from an angle, he appears to have a large white patch on one side of his body that appears raised. He’s been isolated for a week, and hasn’t changed or died. Now I’m noticing the same patch on two of the same kind of fish, and a raised area around one’s eye. The orange Platy, guppies, and mollies seem fine. It looks nothing like Ich, and looks kind of cotton-y or like a dull area. What is this, and what should I do? My babies are in a separate tank so they don’t become a snack. It’s hard to get pictures of these white patches. I was wondering if they might be injuries from the aggressive guppy, or something infecting my tank. And does this guppy look like she’s close to dropping fry? I put her in a breeder for the night just in case, and am upgrading her to a separate tank tomorrow.