I have 2 comets in a tub waiting for transfer into a pond. In the tub which is about 30 gallons, they are inactive and just stay at the bottom. I change 25% of the water every two days and feed them once a day. Is there are reason for their inactivity? I treated them with PIMAFIX just in case and the only time they really move is when I approach and they get scared. One reason might be that the tank is only 10" deep, as it was originally used to contain clothes (Rubbermaid tubs). Could the relatively shallowness of the water be the reason?