So like I mentioned... I got an ASM G 1x protein skimmer with needle wheel impeller and thought it would be an upgrade to put a "larger" rated gph pump on it... not so!!! I returned the Sedra 3500 to the skimmer and for the upgrade, plumbed in a Sedra 2500 needle wheel for recirc... holy cow!!! No kidding... some major microbubbles are filling the skimmer body full and the movement is to the extreme.