Hi all, recently starting today, one of my platies has a curved spine is staying vertically. She seems to have trouble swimming, but I'm not sure what the issue is. We've had the platies since February. Parameters are 0/0/30ish. 75 gallon tank, Fluval 307 + Seachem Tidal 75. Stocking is 10 cardinal tetra, 5 platies (2 male 3 female), 6 julii cory and 1 bristlenose pleco. This stocking has stayed consistent for a few months, but around two weeks ago I upgraded from a 37 gallon to this 75 gallon. Just weird that it started two weeks later, besides that the tank is cycled since I'm using the same filter. Thanks in advance! Just trying to see if it's something that can be treated or if I should euthanize. And if so, if I should treat the rest of the tank with anything. I have a quarantine tank with boesemani rainbows that I would hate to bring into this tank if there's disease.