Tiny bit of algae

[bpdunlv]

I’ve been having a small amount of yellow algae pop up here and there the past few weeks. In the shaded areas. I brush and it goes away easily. So I figured the best solution is a slam to kill it off. I have been having a tough time maintaining my FC levels. They have been dropping down to about 1.5 regularly but I am thinking that may be because my salt cell keeps getting buildup on it very easily and it’s not making enough chlorine.
Anyway I have clear water and no overnight chlorine loss. So should I shock ? And for how should I slaml if I already pass the requirements to finish a slam.
FC 1.5
CC 0-0.5
TA 130
CYA 65-70
Ch 550
Ph 8

I’ve already added MA to lower the PH that is something I have to do 2x per week normally.
And I’m going to add chlorine to get up to 5fc. I had been adding CYA the last couple weeks to get it up. Should I add more?

 

[mknauss]

If you see algae, the best thing to do is raise to SLAM level (28 ppm). If the system is not overwhelmed with algae, it should go quick.

You need to drive down your TA to 80 or so. That and keeping your pH at 7.6 or under will keep your SWCG clean of scale and operating.

 

[bpdunlv]

Thank you fellow Nevadan. So I should just raise it to 28 once and that should be good enough? Should t take the vacuum out of the pool to do it?

 

[mknauss]

No, you need to raise it and maintain it at that level. Once you pass the three criteria, which should be quick, you are done.
Not sure what vacuum you have, but it should be fine.

 

[JJ_Tex]

And after the SLAM (which will take days), make sure you are keeping your chlorine at the appropriate levels.

The chart is in my signature, but 1.5 is wowefully low for a CYA of 70, and even you raising it up to 5 is the bare minimum. You really should be maintaining it at 8-10 on a daily basis.

 

[bpdunlv]

that’s what I was confused about. I already pass the three requirements of being done with a slam before I have started the process. So I wasn’t sure if there was a minimum time that I should do it

 

[mknauss]

that’s what I was confused about. I already pass the three requirements

I’ve been having a small amount of yellow algae pop up here and there the past few weeks.

 

[bpdunlv]

Should I be upping my salt cell output too? This is what the pool installer set it at 3 years ago and I hadn’t had any problems until now.

 

[mknauss]

What SWCG do you have? You should be creating at least 4 ppm FC per day. I am currently set at 4.5 ppm FC per day.

 

[bpdunlv]

The pentair intelichlor i40 It is 3 years old and change

 

[mknauss]

This time of year you should have your SWCG set at 60% generation with 24 hour operation. That equates to 4.6 ppm FC.

 

[bpdunlv]

You run your pool pump 24/7?

 

[mknauss]

Nope. I have an IC40 with a 6000 gallon pool.

You can run the SWCG at a higher % generation if you do not want to run the pump 24 hours per day.

 

[bpdunlv]

Nope. I have an IC40 with a 6000 gallon pool.

You can run the SWCG at a higher % generation if you do not want to run the pump 24 hours per day.

Ok silly question. How do you know how much FC your salt cell produces each day? Or is this just your average FC each day when you tear your water?

 

[mknauss]

PoolMath
A salt cell can create so much chlorine gas per day depending on its design. The IC40 creates 1.4 lbs of chlorine gas in 24 hours at 100%. In Poolmath, Effects of Adding Chemicals, you enter your pool volume, select your SWCG, and then can vary the run time and % generation to result in how much FC is added to the pool based on those settings.

Pools, on average, lose about 2-4 ppm FC per day during summer to the sun. In our area, we are on the high side due to the strength of our sun (few clouds and low humidity). I find I am losing about 4.5 ppm FC with 70 CYA right now. That is why I suggested the starting point for your SWCG settings, to create at least 4.5 ppm FC in your pool volume.