I've noticed that if I locate the diffuser higher in the tank I get smaller bubbles. Has anyone else seen this or are my eyes playing tricks on me?


Also, I found that if I locate the diffuser near the intake of my Penguin hang-on-back filter it sucks almost all the bubbles into the intake.

Is it a good idea to do that or will I loose most of the CO2 in the filter return to the tank?