Trying to solve a problem I’ve had every year of pool operation. I get a Brown/gray sediment with a hint of yellow that settles into “lines” on the bottom of the pool. It seems to be “seasonal” and periodic. I’ll deal with it now and again in late August. If I had to guess I’d say some kind of powdery substance is in suspension and when the water calms down it settles out in these lines. Vacuums rather easily but seems to return pretty quickly.
When I go to the pool store they say “Mustard algae!” and I leave with a ton of chemicals which seem not to help much. I’ve been reading up on mustard algae, it says, “a yellow slime on the walls” and “tends to cling to the walls” both of which I’ve seen neither of.
. . . sparkling beautiful blue water.