Im switching over to a air filtration system. Im gonna be running 6 sponges on a 80, 40L, and 20L. Im running 2 top fin air - 8000 right now. Seems to be doing ok but i know i need more.
Looking at the following
http://www.roguehydro.com/elemental-o2-commercial-air-pump-951-gph/
Or
Pondmaster...