one of my harlequin rasboras seems to have become the victim of bullying in the tank and is now missing nearly all his tail. He has been stuck to the side of the filter for im guessing most of the day (unfortuantly i was in bed as ive been on nights so hadnt noticed until now). He is still trying to swim around but i dont want to put him but in the tank, my krib had a similar problem before and i managed to get its tail to fully grow back. the problem is i have another tank but i dont have another filter that i can set up, is there anyway that i can isolate him in the tank without using a breeding net or anything? i dont have anything like that in the house just a small net for catching the fish, is there any other items i can use to put him in?