an interesting idea you might want to try would be to use a large and tall pvc
pipe (like 4" by 5') as a mechanical filter. Have the water headed out of your tanks drop into the top of this with some kind of easy to get to large particle strainer at the top so you can easily clean this, then stuff the rest with bio balls or filter fiber or ceramics, or really anything. Then have the bottom of the pipe sit in your tank. It's over kill in one of the grandest senses, but hey, nothing TOO wrong with over kill.