i have six tiger barbs and one of them is missing. it had a bad tail fin and i don't know if it's dead or not.if it is dead do you think it could contaminate the water and kill all my fish? and if it does how long do you think i have to find it?
If it has died, it will be releasing ammonia into the tank water, which, if the filter bacteria can't cope with extra bioload, could potentially kill your other fish, yes. You need to try and find it.