Finally happened, help

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
So I have had water in the pool for 11 months never an issue, now I have been really bad about brushing. So I am out brushing today, lol, and noticed a little green algae in one of the coves behind the spa, gets shade, light green on the pool wall, not a lot, brushed it off. So now what?

Tested the water
Cya-55
FC- 5ppm
Cc- 1, maybe could not tell if the water turned pink, maybe just a tad?
Ph-7.7
TA-80
ch-250

So, do I need to now slam the water??
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Darn I really have to slam it, the water is crystal clear. What would cause a small amount algae with cya and FC at correct amounts? I guess if is the only way, it is what it is, just curious as to how it happened, FC has dropped to 3.5-4ppm. But I adjusted the salt cel get to 5ppm
 

AimeeH

LifeTime Supporter
TFP Guide
Apr 2, 2012
2,028
Columbia SC
See this chart Chlorine/CYA Chart

You dropped below minimum FC for your CYA. If my CYA were 55, I'd be shooting for 6FC with my SWG. I have struggled myself dialing in my SWG and suffered small outbreaks just like you've described. Take my words from experience, if you DON'T SLAM you'll constantly be chasing recurring algae......probably in the same spot.

Now you know also, to brushe that area more often too ;)

I've learned the same lesson. Trust me.
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Got it, thanks. I will start the slam today. So do I need to worry about plaster that's 11months old? Also, any concerns about coping and paver deck with FC @ 24ppm?

Also since my cya is at 55, do use 20 or 24 ppm for the FC target? Assume I don't want to complicate things by adding more cya now? This summer I get this all dialed in.
 

AimeeH

LifeTime Supporter
TFP Guide
Apr 2, 2012
2,028
Columbia SC
After 11 months, I'd think you're fine.....based on my reading. But, I don't have plaster so maybe someone will chime in with confirmation.
 

AimeeH

LifeTime Supporter
TFP Guide
Apr 2, 2012
2,028
Columbia SC
I'd shoot for the FC for CYA of 60. We advise rounding up to the next 10 on the CYA test since it's such a subjective test anyway.
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Ok, will wait for comments on the plaster, we filled the pool on 7/29 of last year, I am assuming slamming will not cause any issues, but just want to make sure.

So reading the SLAM directions, I need to bring FC to 24ppm��, turn off the SAlt cell and keep it at 24 ppm until the overnight test is less than 1 ppm drop and cc is less than .5? Wow I might need more chlorine, only have 3 gallons on hand now. Will also drop ph to 7.2.

The chlorine test will be fun, 48 drops for each test, looks like I will need to order more chemicals.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
43,235
Tallahassee, FL
Aimee has you well covered with the SLAM (THANKS Aimee! :hug:)

I am going to address the why it might have happened.....I am going to bet the area has low circulation and you talk about the shade, both of which will equal what you just saw. Throw in the not brushing and FC a tad below where it should be and there you go-algae.

Fit in some more brushing, make sure to hit that area often and keep an eye on the FC and you should be good.

Your plaster should be fine. All of the TFP levels are safe. The CYA acts as a buffer for the FC. The chart is the guide to follow to keep your pool and surrounding area "safe".

Kim:kim:
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Aimee has you well covered with the SLAM (THANKS Aimee! :hug:)

I am going to address the why it might have happened.....I am going to bet the area has low circulation and you talk about the shade, both of which will equal what you just saw. Throw in the not brushing and FC a tad below where it should be and there you go-algae.

Fit in some more brushing, make sure to hit that area often and keep an eye on the FC and you should be good.

Your plaster should be fine. All of the TFP levels are safe. The CYA acts as a buffer for the FC. The chart is the guide to follow to keep your pool and surrounding area "safe".

Kim:kim:
Kim, you nailed it, low circulation area and shade, lol. To be honest, I have not brushed the pool in months, I mean 5-6 months, I know. I figured my water is crystal clear, chemistry was perfect, well during the winter and spring. Once it started heating up to 78-82, and we started getting hot summer sun, my FC was dropping to 3.5 ppm and my cya was still at 40. I believe this is how that algae got me. I am still trying to adjust my salt cell output to pump run time to keep the pool at 5ppm. Again, only a tiny area, but I learned a lesson.

Been slamming since 5pm last night. Will pick up more cya and get that up from 55 to 70. Will be brushing weekly.

Thanks folks. Will let you know the outcome, hoping to be done with this in a couple days.

Last overnight FC dropped 2 ppm. I was not able to test this morning until about 7:30 am, its overcast today was that to late to test in the morning? Do I need to test when it's still dark?
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
43,235
Tallahassee, FL
Does not have to be dark but the sun should not be on the pool yet for the OCLT.

Lessons learned and others can learn from it as well! Brushing is a good thing! LOL

Kim:kim:
 

AimeeH

LifeTime Supporter
TFP Guide
Apr 2, 2012
2,028
Columbia SC
I wouldn't raise CYA until you're done with SLAM as that will increase the required FC but as soon as you've passed all three criteria for completing SLAM then go ahead and raise CYA keeping in mind what your minimum FC will need to be at higher CYA :) you've got this
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Update, looking good, last night at 8:30pm when the sun went down I tested the water FC at 26ppm. This morning at 5:45am it tested at 25.5ppm, might have been 26ppm, so close. The CC level was .5 or less, again, so hard to see the pink color. I did not add chlorine this morning as I am still just over shock level. Will let this go another 24 hours and I think I have it handled.
 

Titan7

LifeTime Supporter
May 9, 2015
663
Fullerton, CA
Okay, here is a curve ball. So I get home and test the FC at 7 pm and it's 15ppm? It dropped from 25.5 to 15 from 5:30 am to 7pm? Now it was in full sun all day. Odd?

So I brushed the pool and put a gallon of chlorine in to bring it to 24ppm. Will confirm at 8pm and do another overnight test.