Question about Black Algae and Dirt

[Guest]

Re Black Algae:

Will scrubbing the spots with a Chlorine Tab really help? Just got back from vacation and black algae that was there a month ago is still there. Treated with algaecide just before we left but obviously didn't help.

CYA 151
Total Chlorine 0.5
Free Chlorine 0.5
pH 7.7

Added 3 bags of shock this afternoon and have been brushing every hour but not sure if the scrubbing with a tab does anything?

Also there is still an abundance of dirt at the bottom of the pool. Was vacuuming, brushing, backwashing etc for several weeks before we left and couldn't shift it and problem is still there. Why does dirt gather at the bottom? We have a pop up system that has never worked great but it's never been this bad. Replaced the cog system before we left and it doesn't appear blocked but it seems to just get jammed on one station every time. Pump is new and the pressure is great but I just can't shift the dirt.

Any tips would be awesome!

(We live in Arizona so it is dusty but like I said it's never been this bad!)

 

[TizMe]

Your CYA is way to high! Your ideal level for CYA should be 30- 50 ppm. If your using powdered shock it will make your CYA increase. You should be using liquid chlorine. In order to get your CYA level to a manageble level you should do a partial drain and refill of your water
What are you testing your water with? What type of pool do you have vinyl, gunite, fiber glass?
Also what are your TA and CH levels?

Read our section on Pool School to see how to clear up your pool.

 

[Casey]

Hi and Welcome~

Your CYA is toooooo high. It should really be 30-50.

Your FC is reaaaaaaaally low. ale:

What I would suggest is doing partial drain refills to get the CYA down.

What is your main source of chlorine?
Did you test the water yourself? What kind of test kit do you use or did you have it tested at the pool store?

Sorry for so many questions... You beat me TizMe!

 

[TizMe]

LOL ! Casey ...

Sorry, dogs had to go potty earlier today !

 

[frustratedpoolmom]

Re Black Algae:

Will scrubbing the spots with a Chlorine Tab really help? Just got back from vacation and black algae that was there a month ago is still there. Treated with algaecide just before we left but obviously didn't help.

CYA 151
Total Chlorine 0.5
Free Chlorine 0.5
pH 7.7

Added 3 bags of shock this afternoon and have been brushing every hour but not sure if the scrubbing with a tab does anything?

Also there is still an abundance of dirt at the bottom of the pool. Was vacuuming, brushing, backwashing etc for several weeks before we left and couldn't shift it and problem is still there. Why does dirt gather at the bottom? We have a pop up system that has never worked great but it's never been this bad. Replaced the cog system before we left and it doesn't appear blocked but it seems to just get jammed on one station every time. Pump is new and the pressure is great but I just can't shift the dirt.

Any tips would be awesome!

(We live in Arizona so it is dusty but like I said it's never been this bad!)

Hi there,
Welcome to the forum!
It would be helpful if you could add your pool specs and equipment into your signature. Go to User Control Panel (top left) and then Profile, and then Edit Signature.

Having a full set of test results and your equipment will help us give you better advice. Living in AZ you can probably get by with a CYA of 60-70 even. Do you have an SWG?

I would read the articles in Pool School, while you are draining off some of your water. Don't drain your whole pool all at once, that could cause problems.

Then I would order a good test kit, like the TF100. That will help you take control of your pool.

 

[Guest]

Black algae doesn't happen overnight. It happens over a long period of improper water balance. In your case, a long period of not enough chlorine and too much CYA. Algaecide does not kill black algae. High chlorine levels and a lot of scrubbing with a brush over time does. If you have a plaster pool you want to use a metal algae brush. First you need to lower your CYA and STOP using trichlor pucks. The only way to lower the CYA is to drain out water and replace it with fresh water.