Hello to all in the known how.
First time poster, long time reader. Bought a house a few years back and maintaned a trouble free above ground, vinyl liner, 21" pool for those few years. This year upon opening the pool after our winter, everything was reconnected as usual and water was balanced as per pool store recommendations and water was crystal clear and balanced with in 48 hrs. Since opening the pool, over time little dark cloudy dust forms in patches around the pool, it appears to form in the direction of the water flow from the return line. I've since vacuumed it on drain and clean once again. Although this dust reappears over time. At first it's in very little patches of dusty dark spots, sometimes greyish white, once brushed, the seem to dissipate but I'm not sure if they go away or just fall right back on the ground. At first I thought ok, sand in filter change. That was done and manifold was carefully inspected and appears to be in good shape. No water leaks anywhere and pressure gage works adequately. Still, this sandy stuff still reappears. Since opening the pool, vacuuming to waste has become a weekly event now (kind of a drag!) and if I dont vacuum, the entire floor will fill with this slimy dusty stuff, in patches in circular direction. Back washing every week now after every vacuum even though pressure gage isn't above 15, the clear bubble indicator shows alot of stuff getting backwashed. I backwas for 5 minuts and rinse for about 2 minuts. This was also done when the sand was changed (the right amount was used).
Any help or advice would be greatly appreciated. I've even considered replacing the filter to a cartridge system, because I don't know how old the filter is, but I'm sure it's still in good condition.