Backyard Aquaponics
A place to discuss aquaponics

http://www.monsterfishkeepers.com/forum ... (1-Viewing) - Yes it works for fresh water tanks too.

This is a DIY method of keeping a culture of algae to control the Nitrate and Phosphate's in a tank. I plan on giving it a try on my tank but mostly for the purpose of feeding the fish. It may also work to increase oxygen in the fish tank if you keep the screen(s) at an angle over a covered tank rather then in a seperate container.