Ive had great experiences with these air diffusers. Generation II Sweetwater Diffusers, 2
I pump a sonic pro 2.9 psi air pump through one of the sweetwater 9 inch airstones in a 10 gallon rez. Under a 1000 hortilux, a big bushy girl fed with good nutes,67 degree root zone, and that many bubbles, 2 inch massive colas are the result. Make sure to get the elbow MNPT fittings and Heavy set weighted air tubing doesnt hurt either. Peace