Hello, I'm new to the forum and have a question. I just installed a Pentair Intelliflo VS-3050 and a Pentair Clean & Clear 520 cartridge filter. I have a 20x40 inground that is 35K gallons. I have the pump scheduled and it runs great. However, it pulls very week from my skimmer when I have the valve set on drain and skimmer. If I move the valve to just skimmer, it throw a code to "Clear the drain", which I've seen on here several times. All my lines are clear (I can prime off just the skimmer and it pulls in tons of water) or if I switch to just drain, it does the same thing. I can obviously run the pump on both, but how do I vacuum? I used to switch to just skimmer to get maximum suction, but I can't with tripping the code. Suggestions? Thx