Help please

[Caprishea]

Can anyone tell me what might be going on with my little guy??? He was perfectly fine, all my water parameters are good. I just lost my pufferfish the day before yesterday then last night my lion fish has a spot like this on both sides. I’ve already pulled him from the tank to QT. Is there anything I can do ??

 

[Timfish]

"Possibly" Uronema marinum. Do a search with tthat term to see all the simptomology and see how different people are treating it but antibiotics should help if that's what it is.

(FYI it does help to list all the parameters including water change frequency, lighting conditions and feeding.)