Also when you said you turned that valve and the water started coming out faster from the waste line, that would be your flush valve. Every couple of weeks or so open that valve to where the water is running faster to flush out the membrane. What it's actually doing is running water over the membrane at a fast rate to loosen up some of the larger particles and anything that can be removed in that manner, it helps the membrane last a little longer.

BTW just for your own reference, that valve is bypassing what is called the restrictor valve.