You'll find that a wavemaker is a total waste of money and time ("gasp! Dear God did he really say that!!!") when you have a couple mods pushing flow toward each other or directed at a wall either tangent ot perpendicular. The flow starts at 2" dia. low pressure and I'd guess in the 700 GPH range (no discernable difference in 900-1200) and runs out in a cone out to about 12" dia at 18" or so from the pump. The flow is diffused somewhat but one creates enough flow to rock my corals on the opposite side of my 48" tank. 2 in my 120 generate random flow all over with the bulk of surge being in the direct stream path. When they converge or are disrupted by LR work the flow is excellent. Because of the widening path of flow it;s really not necessary to Keep them low in the tank and I actually think the fish appreciate some eddy areas down low because they spend alot of time dodging the flow when it's heavy. I randomly turn off one pump for a day or 2 then the other, and both for picture day.... Ya, the low instance Stack-O-wavemaker... LOL