I'm NOT having fun

[Chaloupa]

Sounds like velvet to me...I had a very robust healthy Niger Trigger, Strawberry Pseudochromis, yellow wrasse, True Percula, all doing well, then I added a Kole Tang and a Valentini....well the Valentini met the powerhead and from there...I lost the Tang first, then the Pseudochromis, then finally the clown, the Trigger had been evac'd out and the yellow wrasse didn't become affected at all....Velvet hit my tank and hit it hard and suddenly...it sucked. Good luck to you...I know we took the clown out and tried to treat him with Copper but he just didn't make it...his chances were slim but ...UGH! we almost took the tank down...but put a UV on it for 2 weeks with the remaining wrasse, water changed lots...and now are adding fish again.