Last night, my halfbeak developed the bend in the spinewhich means he isn't going to recover. I shoudn't of switched its tanks. The tank with all of the sick fish recovered this morning. He was one of my favorite fish, and I hoped that if I moved him to the brackish tank he would be happy like my other one who is living there right now. I was an idiot for thinking that. the halfbeak was fine immediatly, but the 2 were fighting now, so I had to move it back. This is how it got the bend in its spine.