I think therre are way to many factors to draw a line on do or don't. Size of the tank compared to the size of the filter would be the big one.
I am sure someone has had a very bad experience using two, and they will tell you the down side.
__________________ Trying to breed GBR (standard and high fin), Discus, Angels, and currently breeding 6 types of guppies, 5 types of swords, 2 types of mollies, and RCS. |