I recently bought this house and now I have my first pool! After reading and searching a bunch of threads, I have identified all of my pipes, but seem to be having a problem with my main drain. I have been able to accurately manipulate all of my levers with accurate results, but when I open my main and close everything else, I get some water, but no where near the flow of the skimmer or the spa drain. I have also tried all possible combos of main/spa/skimmer with the same results that include bubbles out of the jets. I can see some wather coming into pump basket, but not a lot, so I am thinking a blockage of some sort. When I got the pool, a service was taking care of it and they just had it set at full skimmer, and it must have been that way for some time because the sun has bleached the lever positions in position. What is the best way to diagnose main drain problems? Scuba gear and a snake?? Of course there could be some other setting/ issue with my set up I am not aware of that is causing my issue, another reason why i'm posting!! two pics attached for info. Currently waiting for my test kit, been going to Leslie's in the meantime. The pool is estimated at 16x32 avg 5 ft deep =19200. Leslie's has me estimated at 15500, which is why im having other issues, but that's another thread. Thanks for the help!