I was away from my pool for three weeks. I use the trouble-free method and never have any problems.
When I took the solar cover off upon returning home, the water looked fine, but there are several large light-gray or light-green blotches on the bottom of the pool, both in the shallow and deep ends.
The water tested:
TC and FC: 5
pH: 7.1 (it was 7.5 three weeks ago)
While away, I used a chlorine feeder to keep the chlorine up. I normally don't use the feeder. I like to keep the CYA down.
The pump was on 10 hours a day during the 3 weeks. We live by many trees, and there were a lot of leaves at the bottom of the pool - scattered everywhere.
Are the splotches algae? I didn't think it could form with the chlorine at 5 or above the whole time.
Thanks for any help.
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- 17,000 gallon in-ground
- Vinyl liner (new last year)
- DE filtering
- Sta-Rite pump