Okay so I made one of those filters with a plastic three tier drawer. What I want to know is if these are any good at filtration, mechanically and biologically. I currently have it full with nylon scrubbies, pot scourers, some sponges I bought at the dollar store and then I have these three filter circles from a pressurized filter that have small, medium, and larger holes. Is this good enough? Prior to making that filter I wanted to make a filter out of a 110 gallon poly tub I have for holding fish in. What I WAS going to do was place it higher then the pond, basically an opposite version of a skippy filter. Which would be better?