Usually the membrane fine bubble diffusers have built-in check valves. Ask before buying. Keep in mind that as you split or divide the air volume each diffuser will receive less air and produce fewer bubbles which often means a smaller sized diffuser can be used for smaller air volumes. There becomes a point where the diffuser is too large for the amount of air it receives and it does not operate efficiently. No use buying a large diffuser if it will receive only a small amount of air. Just because the diffuser is large does not mean it will produce a large boil.
Last edited by Bill Cody; 05/18/12 04:11 PM.
