We have a 15 x 30 pool with 54" walls... our pool store says this is 10,000 gallons, but we use 14,000 in for our math based on volume equations we've found online.
CYA = 30
FC range is therefore 2-4
We aim FC for 6, test multiple times each day, and have never fallen below 2.
Brush every other day, vacuum weekly, vacuum to waste every other week
CC = 0
Water is crystal clear
Tons of activity and splashing in the pool on a daily basis
We use the BBB method taught here
We use the test kit recommended here
Entire pool gets full sun all the time
Overnight loss tests for the last week are all much less than 1 each night.
We've tried aiming the inlet a few different directions.
We have a greyish sediment across the entire pool bottom. If you touch it, it poofs away. Kids splashing, poofs it away. Nothing on the walls. Ladder is clean. Around the skimmer and inlet is clean. Pool toys not left in.
We vacuumed to waste yesterday, backwashed the filter, and covered the pool overnight (unusually cool night). No sediment at all when we went to bed. First thing this morning before any sun is out, the sediment is back. Overnight loss was about .4. Water still crystal clear. FC still at 6 (above the 2-4 required range). CC still at 0.
I feel like we're checking everything and are OK - just pollen or similar, not algae - but wanted to gut check with you all to see if there's anything else we should consider. I remember some recommending adding DE to the skimmer basket to help capture fine sediment. Maybe that's all we need to do?