Hi everyone, we have rain for the next 2 days (3-4 inches) and my pool is already very full. I wanted to drain the pool a couple of inches as it does not look like there is any overflow basin built into the pool. From my limited knowledge I think I can switch the port on the sand filter to "waste" and than turn on the pump.
My questions is two parts, firstly when I switch the port from Filter to Waste without the pump being on I can hear water rushing ( I assume to the drain), so I am not sure if the pump really needs to be running? Second question I have is that the valve that controls the backwash and I assume waste port is the same pipe. So does this pipe valve need to be closed when the port is switched to filter or can it remain open. I do not hear any water running with the pipe valve being open and in filter mode (with pump off) but as soon as it is in waste mode water rushes out to the drain. I have attached some pictures for reference. One is for my spa (orange valve) and the one with the blue valve is for the pool.
P.S My PSI is normally around 20 when in filter mode and in waste mode it is 30. I am not sure if this is an area of concern.