I have no idea how to open my sand filter. And I recently had surgery on my dominant arm which I am not able to use much at this time. So I’m at a loss. Balancing my chemicals and getting my chlorine level appropriate Will do me no good in a pool that is poop colored from rust. I have a filter on my hose so when I am adding water hopefully I am filtering out most of the iron therefore not adding as much to the pool as I am taking out with each Backlash