Water getting algae after a few days. Not sure what I should try.

[Cloneman315]

My pool is a vinyl approx 15360 gallons. Water is very clear but after several days we get green spots and when you brush small green clouds. Last year I installed a ic20 it is currently running 60 percent and showing good salt levels. Today is the first warm day and water is about 79deg. My tests are as follows

Ta 80
Ch 100
Cya 35
Cc 0
FC 2.5
Ph 7.7
Salt 2330 per strips but ic20 says in the good range? Which I think is 3000 to 4200

So it appears to me FC is a little low. Do I add more salt and if so should I believe the strips or the ic20 for results? Pump runs a total of 10 hours a day as the automation handles that. Or should I just turn my ic20 up to 80 percent?

Thanks
Brian

 

[Richard320]

Cloudy water and algae on the walls means it's time to SLAM. Even on max, the SWG won't be able to keep up with the demand. You need to kill that algae faster than it can reproduce until every bit of it is gone. Then raise CYA up to about 70 and maintain FC above 3 at all times. If the SWG is happy with the salt level, I would be, too. Worry about that later. Kill that algae!

 

[Cloneman315]

I also added the pentair de which I am totally amazed with the difference over the sand. I will head to walmart tonight and shock. Cya to 70? Wow that seems high? Care to explain?

Thanks!

- - - Updated - - -

Also having algae why do I not see any cc?

 

[Richard320]

I also added the pentair de which I am totally amazed with the difference over the sand. I will head to walmart tonight and shock. Cya to 70? Wow that seems high? Care to explain?

Thanks!

- - - Updated - - -

Also having algae why do I not see any cc?

You're running a SWG. Check your owner's manual. (page 14) Check Pool School. You can run a higher CYA because you have a slow steady addition of FC. So a higher CYA and a lower minimum FC than you would in a bleach pool.

DO NOT raise the CYA until AFTER the SLAM process is completed. Until you have passed all three criteria, consider yours a bleach pool.

You won't always see CC if it's just algae being killed off. And what CC does get created probably dissipates in the UV rays from the sun so you never read it. Hence, three absolute tests to consider the SLAM done. CC alone is not a surefire test.

 

[Cloneman315]

Makes sense with the swg. That and the de was well worth it. Will shock this evening