I didn't know that otos couldn't have salt too. Acutally... I wasn't even thinking about them. One of my discus has been rubbing on plants, not all the time, but enough to make me worry a little. So I decided to salt the tank just in case its flukes and just keep a close eye. Well I salted what was recommended (1 tbsp per 5 gallons) A little bit later one of my otos seemed to just drop dead. 
The other two seem ok, but I'm removing them to the other tank for the time being.
The other two seem ok, but I'm removing them to the other tank for the time being.
