I cannot get rid of the algae in my pool ?

[Creativeps]

I had my pool put up in October 2016. Over the winter it got a little bit green. I went to the pool store and spent a bunch money. And they don't know how to get rid of it. They tell me my water chemistry is good and they don't know why it's green. I bought the TF 100 kit.

I had a pool for 15 years and I never had this problem. Please help I'm lost

FC. 3
CC 1
TC 4
CH 75
TA 130
CYA 70

 

[tim5055]

Welcome to TFP!!

It's easy, your chlorine is too low for the amount of CYA. The pool industry refuses to recognize the connection between CYA/Stabilizer and the ability of chlorine to do it's thing sanitizing the water. others here can give you the scientific details if you want, but lets just say CYA locks the ability of chlorine to sanitize. The more CYA you have the more chlorine you need to keep in the pool to keep algae at bay.

If you look at our [FC/CYA][/FC/CYA] you will see that for a CYA of 70 your FC should never be below 5, and you should target 8 - 10 to keep it above the minimum.

Now that you have algae yo need to follow a process we call a SLAM Process.

But a SLAM Process is easier to do when the CYA is about 30 (less chlorine is needed). To get the CYA down you will need to exchange a little over half of your water.

How much Pool School have you read? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool
Turning Your Green Swamp Back into a Sparkling Oasis

 

[Creativeps]

OK..... i'm in the process of emptying out better than 50% of my water. And then I will fill it back up and redo my chemical testing is this correct

 

[Akathisia]

Yes. CYA 30. PH 7.2-7.5 then start the SLAM. See links in tim5055's post.

 

[stodds]

Oooh. I like this one already. The person asking for help has obviously read up a bit, but is ready to take advice, and have the experts "check his math." This will be easy. Welcome to TFP

I've seen too many success stories myself to ignore advice from these great folks. I'm guessing you have too, Creative.