sick damsel

So, I was given a damsel and some inverts from a family who didn't have the means to continue to care for it. It seems to swim very well, though it does prefer to hide, and show some signs of significant aggression. Since I got the fish last week I took some of the sand with some new sand that...

Hi all, this yellowtail damsel is two days new into the tank. Initially, he swam around fine, and then found a hiding spot in a rock. But today, I found him on the sand bed on his side, gasping for air. I don’t have an established quarantine tank, so I put a strainer at the top of the tank and...

I got to act pretty fast here. So I have 8 Fiji blue devils in a 10 gallon QT. One (the one in the video) has bruising pretty bad but all the others seem to be alright. How do I treat this guy for the best outcome? Second day in QT I used 50% display tank water and the rest new. Salinity is at...