diy protein skimmer, help please

[draczka2]

i'm trying to build a counter current skimmer. it is 4" dia. and the reaction chamber is 36"tall. the problem is that i'm unsure on how many bubbles is to many. i read that 13% air to water is the most you can have without running the chamber dry. i made a airstone manifold i got off line, it has three stones on it. i feel i'm actually not getting enough air bubbles. i have a tetra 7.25 psi rated pump. i can only submerge the stones about half way before bubble production drops big time. my question is, is this pump to small,and if so what is a goodone to get?

 

[darknes]

IMO, the best air pump you can get is the Tetratec Deep Water air pump. They are a little more costly, but you'll see a huge difference. They are made to pump air through large heights of water.