Got new pool installed, need to do a vacuum and pool company is coming back during week to explain but I can't wait any longer. It's a cartridge Hayward filter. There is a little cap that goes over filter he in both skimmers. I obviously plug one to get max suction and then attach vacuum into skimmer other end on vac head. Is there anything else I do on valve side where plumbing is?? Bottom is very sandy due to paver install and want to clean this up ASAP. Thanks!!