Quote Originally Posted by bell7272
great.

This is very helpful.

What psi should I look for when it's clean and at what psi should I backwash.


Thanks.
Depending on plumbing and pump size the pressure can be anywhere from ~8 - 20+ psi when clean. The way to determine when to backwash is to make note of the starting pressure when you know the unit to be clean and freshly de coated, when you see an 8 psi increase, it's time to backwash (I was going to ask why you'd backwashed @ 13 psi, but forgot to), in the past, I have used a grease pencil to mark the pressure gauge to show the 'backwash psi'. As a note, don't be alarmed if the filter's starting pressure rises 1 -2 psi from year to year, it's just a sign that the grids themselves are getting a little clogged and need a little chemical soaking. Glad to have been able to help!