Hi everyone! I'm Jason, long time fan, first time poster.
Problem: While backwashing filter flow starts full, then within seconds, slowly starts to reduce until water flow coming out is about 1/2 to 1/3 of normal during backwashing (which typically maintains the same high flow throughout the backwashing process). Flow does NOT reduce when running in RINSE mode or in WASTE mode. Only happens in BACKWASH and starts off high and reduces quickly. Haven't backwashed in about a week or two, never happened prior to today. Pressure before backwash wasn't not very high (just touching yellow area, forgot the PSI exactly), but lower than when I usually backwash, but since flow seemed low as evidenced by my skimmer not skimming due to lack of sufficient suction, after first checking all grids and lines, figured it must be the filter needing backwashing. It's skimming now, but not impressively so, but clearly backwash helped a little at least on that end.
Pool: Intex 22' UltraFrame above ground pool
Filter: Intex Krystal Clear Sand Filter Pump for Above Ground Pools, 3000 GPH Pump Flow Rate, 110-120V with GFCI
SWG: Intex 120V Krystal Clear Saltwater System CG-28669 with E.C.O. (Electrocatalytic Oxidation) for Above Ground Pools
Skimmer: Intex Deluxe Wall Mount Surface Skimmer
*Amazon links provided for equipment clarity for the same of specificity.
Skimmer basket and inlet lines and filter grids are all clean. Considering that RINSE and WASTE water flows are fine, I'm guessing pump and lines up to the filter are all good. After backwashing, PSI only dropped 1 or 2 psi after, still remains kinda high... (just below the border between the green and yellow areas on the gague). It morally sits around half way into the green after backwashing.
I played around switching between backwash, rinse, recirculate, waste, etc.... but to no avail.
Pool and pump is 1 year old, filter is about 8 months old (but not run for 5 months during winter). SWG is about 1 month old.
Thank you for any help!