Just purchased a house with an IG vinyl pool. Getting a handle on water chemistry with BBB program but not sure how to do filter maintenance. When we moved in a week ago the filter system was running 22 psi but today it was at 29 psi. I think this indicates a need to backflush the sand filter but not real comfortable doing this the first time. Also not sure when the filter medium was last changed, I know the pool was left open this past winter. I am more of a visual learner and although I have read the procedure for backflushing just nervous about not setting something correctly and messing up majorily. Thanks for any help. Steve.