I have a forktail blenny. Its very active and likes to attach itself to the wall to sleep. Generally, it eats like a pig. Five days ago, it stopped eating. The next day, it could not attach itself to the wall and became weak. I moved it to a qt tank when it couldnt resist the pull of my wavemaker. Besides not being able to stick to the wall, it developed a vertical black band on its tail. I treated with prazipro. It appeared dead several times, but would start swimming when i tried to get it. It still isnt eating, but is now swimming better and the black band is gone. The fish seems less stressed( breathing better). It hasn’t tried to stick to the wall. My question is what might have happened? All other fish are fine. No new fish for two months(all qt). I did add some snails and a fireshrimp that were quarantined by dr reef. My first thought was flukes. Parameter wise, my phosphates are high at 0.08. Salinity 1.024, nitrates 5, ammonia 0.