Help! We have a 10 gallon tank that had a dwarf gourami, 2 platys, and 3 mollies. Our power filter (which was rated for a 10 gal tank) has suctioned the platys to it and killed them. The bigger fish do OK, and our baby mollies seem to do well, even though they are smaller than the platys were. Is there a modification that we can make to our filter, or a new one that would not cause this problem? What about an undergravel filter? We are afraid to buy any small fish and have this happen again. Thanks for any input!