Ok, i'm a little confused as to the normal behaviour of my Otos. I originally bought four, but lost one the next day. He wasn't doing too good when I brought him home. Then out of the remaining three, there was one that swam constantly moving between the plants and glass eating everything. The other two just kind of hang out on my amazon sword leaves most of the day. I thought the energetic one was behaving normally, then yesterday he up and dies for no reason. I checked the water params and ammonia=0 nitrites=0 and nitrates=10. So are the other two behaving normally? Or will i prob. lose them too?