Sunday - Cloudy pool. Added chemicals and got numbers right, Tuesday GREEN pool - Please help

[stokercw]

21x21x52 agp. (11,500 gals)
Three weeks ago, I started off with a cloudy pool, which then turned green.
I did a lot of reading in the forums and bought the K-2006 test kit.
Zero FC.., PH was good at 7.4
Shocked the pool by adding two gallons of bleach (6%)

Green cleared but still cloudy. Shocking pool raised my PH so I used PH minus to lower PH.

Sunday - very slight algae - still some cloudiness
PH 7.3
FC 1.5
CYA 40
Added 36 oz of bleach
Monday (could not check)
Tuesday - Green pool again!!

Please help!!

 

[mknauss]

Welcome to the forum!
You need to follow the SLAM Process.
The liquid chlorine only raises pH very temporarily. Never test pH right after adding liquid chlorine.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[stokercw]

Thank you,
So based on this chart and my CYA of 40, using the calculator I should add 3 gallons of 6% bleach.
I should also mention that yes, I was testing my PH IMEDIATELY AFTER adding bleach

CYA (Stabilizer)	Minimum FC	Target FC	SLAM FC
20*	2	3-5	10
30	2	4-6	12
40	3	5-7	16

 

[mknauss]

That is the correct amount of 6%. Watch out for household bleach, really hard to find it without scent, splashless, Cloromax, etc. Clorox bleach is not a good source.
Best is to find 10% at Walmart, Home Depot, etc.

Once you raise your FC to 16 ppm, pump is to run 24/7 until the SLAM is over. Test your FC as often as possible (at least 3-4 times per day) and add liquid chlorine to raise your FC back to 16 ppm each time. Brush as often as possible.

 

[Richard320]

Thank you,
So based on this chart and my CYA of 40, using the calculator I should add 3 gallons of 6% bleach.
I should also mention that yes, I was testing my PH IMEDIATELY AFTER adding bleach

Whatever it takes to get to 16 FC. But remember, this is a process, not a one-time megadose. SLAM means Shock Level And Maintain. So a couple hours after you've added all that bleach, you'll need to test and add some more bleach. Again and again and again until you pass all three tests. And "the water is clear" means even after brushing. It means you can toss a quarter into the deep end and at least see it. Ideally, you'll be able to call heads or tails....