My ozone was set up like DDboys minus the check valve because it was above the water. I used a Luftpump by coralife and no T. This air pump is adjustable and no T made my skimmer silent. No sucking noise. W/O an air pump you are really restricting the air to your skimmer, the suction of a KSP9000 is okay, but not enough to pull air throiugh an air dryer, OZ unit, check (valve if installed), and all the extra tubing. If you do a T and don't have an air pump it will pull more air from the free side of the T because that is the path of least resistance - IMO.