I have a 30000 gallon below ground pool. I am pretty new at this but am learning as I go. We get ALOT of very small debris on the top of the pool and when I feel on the return pipe on the skimmer, there is very little suction. The vacuum works great and is on its own return line and I am not sure about the bottom drain. At the pump, there are two return pipes and one has a turn valve. When I open it up all the way the suction at the skimmer basket returns but it is weak. Two main questions, is my pipe from the skimmer clogged? and should I open that valve all the way?