

Please help me save my fish
My strongest fish has been unable to swim normally for the past few days ever since the power went out because of a storm. I thought that may have had something to do with it but im now seeing a grey fuzzy thing or unusual grey texture or scrape that’s on her side. Does anybody know what that could be and if that’s whats making it difficult for her to swim horizontally. she’s trying her hardest so I’m really sad that she’s struggling.
the tank size is medium-ish and normal ph. I have to ask my parents. They are extremely diligent about the water quality and tank care.