If your PSI gauge is working decently, assuming the sand filter is in good working order, after a good backwash check to see what your PSI is and call that your start PSI. Once it goes up 25% from that, it's backwash time again. So if your PSI gauge showed 10psi after a backwash, you could backwash when it hits 12.5 PSI. (Note: after the pool is all clear you may see your post-backwash psi be even lower than it is now. Use the lower PSI as your start value from there on out)
Also, when you backwash, be sure to turn off the pump first, adjust setting to backwash, turn back on, let it backwash until it runs clear no matter how long it takes whether 20-30 seconds or even if minutes, pump off, change setting to RINSE, pump on, run 15-30 seconds if always clear, pump off, change setting back to backwash (again) run 15-30 seconds, pump off, change setting back to RINSE (again) pump on run 15-30 seconds, then you're good to turn it off, change to filter/recirc whatever you're needing, then back on. (any of those times should be extended if water isn't clear yet, always end each step with clear water coming out)
I didn't know about the Rinse or the repeating the backwash/rinse when I started at my swamp. If you already knew, congrats!
Also, if you do end up having to drain any water at any time, I highly suggest trying to siphon vac from the bottom of the pool...it takes water out, but also algae sludge and leaves and needles and pollen. Just that alone took my pool from dark brown to dark green!!! Just be sure to check your local water prices before going too crazy with it. Bleach might be cheaper than water for you. You have some great people giving you advice! No need to every shy away from asking questions. No worries about just one more question, they love people like you that ask and do what they suggest.
Also, when you backwash, be sure to turn off the pump first, adjust setting to backwash, turn back on, let it backwash until it runs clear no matter how long it takes whether 20-30 seconds or even if minutes, pump off, change setting to RINSE, pump on, run 15-30 seconds if always clear, pump off, change setting back to backwash (again) run 15-30 seconds, pump off, change setting back to RINSE (again) pump on run 15-30 seconds, then you're good to turn it off, change to filter/recirc whatever you're needing, then back on. (any of those times should be extended if water isn't clear yet, always end each step with clear water coming out)
I didn't know about the Rinse or the repeating the backwash/rinse when I started at my swamp. If you already knew, congrats!
Also, if you do end up having to drain any water at any time, I highly suggest trying to siphon vac from the bottom of the pool...it takes water out, but also algae sludge and leaves and needles and pollen. Just that alone took my pool from dark brown to dark green!!! Just be sure to check your local water prices before going too crazy with it. Bleach might be cheaper than water for you. You have some great people giving you advice! No need to every shy away from asking questions. No worries about just one more question, they love people like you that ask and do what they suggest.