FAC at 19.9 and TC at 20.7, green yellow, what happened ?

[Lou-AZ]

Leslie Pool Test says pool water is @ 19.9 FAC and @ 20.7 TC . . . and has been green for 10 days. PH 7.2, Tot alka 120, Cal Hard 593, Cya Acid 77, Phosp 334, TDS 3425.
Pool "service" is bi-weekly. They shocked it again week ago Tues., and typically put 6-8 tabs in float. I vacumed 3 days ago and yesterday, when i took water test to Lesley. Backwashed but never reall got "dirty" water . . . started and remained pretty clear. Pool "service" (Spli-Spla) says filter media should be changed. It was done last year with 6 or 8 sacks (can't remember exactly, looking for receipt) of new Pool Sand. Have run filter 16 hrs a day for a week ! Nothing has improved. I'm thinking it is a CHEMICAL issue, not Filter Media issue. What happened ? Thanks for responding ! Lou in Aridzona

 

[mknauss]

Welcome to the forum!
You need to follow the SLAM Process. To do that, you need a proper test kit. I suggest the TF-100 or Taylor K2006C. A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.

While you are waiting on your test kit, add 5 ppm FC worth of liquid chlorine / plain bleach to your pool each evening with the pump running. This will replenish the FC lost each day to the sun and also inhibit any algae in the water from growing further.
I suggest you read ABC's of Pool Water Chemistry.

 

[Msch99]

Correct on not a filter issue. Filters remove particles but do not help kill algae.
The reason a proper test kit is recommended is because pool store tests are notoriously inaccurate, as are test strips.

Guessing the pool service uses tabs for chlorine? If so, I would bet your cya is much higher than 77 which would tie up your FC.

A minor investment in a proper test kit will save you time and money very quickly, and will give the experts here the information they need to help you have a sparkling pool!
After they get it cleared up and if you follow their protocols, you will spend more time swimming and less time taking care of it! (And do away with the bi weekly pool care.) Thinking about taking care of it is more intimidating than the actual process!

 

[YippeeSkippy]

With your size pool I would suggest one gallon a day of chlorine and brushing the pool daily to disrupt the algae, while you're waiting for a good test kit to arrive.

As for test kits I would recommend the TF-100 or Pro model. It has the most reagents for what you'll be needing, and you must get a FAS-DPD tester for FC and CC (up to 50ppm)

You seriously would benefit from a Salt Water Chlorine Generator. (...and ditching the pool guys and do it yourself easily )

Maddie