I read the reviews about low flow and volume and honestly, I'm not sure what the folks are asking for. This unit installed right to my Intex 18' above ground with the included sand filter. Installation took 5 mins (and I didn't even shut the pump down to do it).Depending on the bypass adjustment, I can put a 4' high waterfall down in the middle of the pool (9') without any issue. There is no increase in back pressure shown on the gauge. I rotate the bypass ring to create a circulation flow under the water to keep the water moving and put a nice cooling waterfall down about 5' to 6' out.There are 3 benefits.1. Its aesthetically pleasing and relaxing to hear the water.2. It does actually help cool the pool water. I've seen 5 to 8 degrees drop in pool temp. (pool is in Texas on a concrete slab... It will get to the point a hot bath is cooler...)3. It's a GREAT indicator of your filter condition. If you see the waterfall not going as high or as far, check your filter. A quick (and probably needed) backwash and your good to go.