Light greenish stains on walls at deep end of pool

[goober71]

Hi All,
We've had our pool for a couple of years now. Everything has been going well so far. This season, i'm seeing some green stains on the sides of the pool in the deep end (6ft). I've been pretty thorough with keeping the chlorine level up and brushing. Brushing will lighten the stains, but they don't disappear completely. Any way to get rid of these? Is it just stubborn algae? or something else?
Any help will be greatly appreciated.
Thanks.

G

 

[splashpad]

Can you post a full set of test results?

 

[goober71]

Hi,
Sorry for the delay. Here are the results from this morning:
FC 6, TC 6, PH 7.4, TA 70, CH 260, CYA 80.
I shocked it a couple of days back. The algae brushes away when i brush it, but the light greenish stains remain at the deep end, on the walls. I'll try to post a pic as well.
Any help will be greatly appreciated.
Thanks.

G

 

[mknauss]

Can you let us know what test kit you are using? Also, how do you chlorinate?

If you have active algae you need to follow the SLAM Process process.

Take care.

 

[goober71]

i use the Taylor K-2005 test kit. I use 3 inch tabs to chlorinate with an in-line chlorinator. Also shock the pool every 7-10 days with Leslie's bagged shock.
The pool looks nice and clear blue, except for these stains. Is a SLAM still needed? Will the bagged shock not take care of it?
Thanks.

G

 

[goober71]

 

[JamesW]

What is the original color of the plaster?

 

[mknauss]

Your K2005 can be upgraded to a proper test kit by purchasing a FAS-DPD test kit. TFTestkits.net sells them.

Do the pucks you use have copper in them?

Your regimen is not conducive to long term success.

Read
Pool School - ABCs of Pool Water Chemistry
Pool School - Chlorine / CYA Chart
Pool School - Recommended Pool Chemicals
Pool School - How to Chlorinate Your Pool
Pool School - SLAM - Shock Level And Maintain

To properly complete a SLAM you will need to upgrade your test kit and use liquid chlorine. Your CYA is also quite high and will pose difficulty in completing a SLAM.

Take care.

 

[goober71]

The original color of the plaster is white, with the 30% blue quartz addition, which makes it look blue. No issues with it, except for these sections that seem to have the greenish stains.
Will algae stick to the walls, such that it leaves a light green stain-like layer even when brushed?
I'll order the FAS-DPD kit and then complete the SLAM when i have it. What changes should i make to the treatment regimen? Switch to liquid chlorine? The issue i have with that is having to add it daily or every two days. Any way around that?
Thanks.

G

 

[funandsun]

Hi,
Sorry for the delay. Here are the results from this morning:
FC 6
CYA 80
G

Is this a saltwater pool?

What are the ingredients listed on the bag of leslies shock you are adding every 7-10 days?

 

[splashpad]

i use the Taylor K-2005 test kit. I use 3 inch tabs to chlorinate with an in-line chlorinator. Also shock the pool every 7-10 days with Leslie's bagged shock.
The pool looks nice and clear blue, except for these stains. Is a SLAM still needed? Will the bagged shock not take care of it?
Thanks.

G

So you only use solid forms of chlorine?

Can you share pics/specifics of the tabs and bag shock you are using?
One or both could be significantly raising your CYA level and possibly adding copper (random guesses without specifics)

 

[goober71]

Hi,
I have been using Clorox Pool and Spa Xtra Blue 3" tabs this year. The tabs and the shock packets did not seem to be having an effect on the algae stains.

So, as recommended earlier on this thread, I did a SLAM process with Liquid Chlorine (10%) from Walmart. That completely removed the greenish stains and completely cleared the pool water. This was about 3 weeks back and it has stayed clear since then. I've been brushing once a week and supplementing the chlorine tabs with liquid chlorine as needed to maintain the FC level. I leave the dial on the inline chlorinator about midway.

How often do i need to do a SLAM/Shock? Is it only when i see algae? Any downside to raising the chlorine level that high, even for a day or two? Will it eat away at the plaster or anything like that?

Thanks.

G