Black algae ??

[G-Honey]

How to treat what I think is black algae ? I have raised my FC to 7.5 but how long should it be raised to be effective ?

Pool size: 13,000 gallons
inground gunite
Hayward pumps 2 hp two speed
280 polaris cleaner
sand filter

 

[mknauss]

Black Algae

This guide provides a step by step procedure for eliminating black algae in your concrete or gunite pool. Read full post here.

www.troublefreepool.com

What test kit do you use for pool water chemistry testing?

 

[jimbethesda]

Here’s some reading for you:

Algae Archives

www.troublefreepool.com

7.5 is likely too low, but you’ll need to know your CYA level.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

How are you testing your water?

 

[YippeeSkippy]

How did you arrive at 7.5ppm FC being the magic cure? How high is your CYA?

Maddie

 

[G-Honey]

I’m using a Taylor K-2006c kit. I just ordered a stainless steel brush so that I can brush the spots. I don’t have many, but I don’t want it to go crazy. I want to nip this in the bud. My cya is 40. I also have a pebbled gunite finish, so it’s not a smooth finish. I wonder if this finish is more likely to get black algae to grow. I try to brush weekly. By reading, I need to brush spots multiple times a day plus raise my FC between 7 and 16 for a week. But i need a strong brush which I have ordered. If anyone has any more ideas , please help me. Thanks

 

[mknauss]

Great on having a quality test kit. Can you put that information in your signature?

Follow the guide I posted and brush the spots. It may take longer than a week of elevated FC. Do it until the black algae is gone plus several days.

 

[YippeeSkippy]

Find some old shorts and a tee shirt you can get wet in. Getting in may help you scrub better.

 

[JamesW]

Do you have any pictures?