I have read countless threads on how to maintain my pool, and I have learned a great deal.
Unfortunately, I am still at odds as to what is happening in my pool.
What I am seeing is after 2 to 3 days, I continually get a return of something on the vinyl liner. When I brush it, the appearance is a greenish smokey cloud.
I have been keeping my FC at or above target value for my CYA level. The pool water looks great, has good clarity, doesn't smell, taste, or otherwise look bad. I vacuum with a manual vac only as needed (maybe 1x every 2 weeks based on weather)
I backwash my sand filter more than necessary.
Can anyone tell me what's happening? How can I have algae with no CC showing? (I use the FAS/DPD test, daily)
I just got off a round of shocking about a week ago, for pretty much the same thing...only it was worse since I was not home for a few days.
My pool is:
18,000 gal inground vinyl liner
300 lb sand filter with bottom drain, aqua genie side skimmer, and 5 additional returns.
The filter runs on a timer for a total of 9 hrs per day
Tonights numbers (before brushing and adding bleach)
FC - 5.5
CC - 0
PH - 7.4
TA - 80
CYA - 40-50 (someone find me a better test than the black dot!)
Temp - 90
Any help is greatly appreciated!
Thanks in advance!