Question: SLAM for algae versus Stain Removal?

Gene1939

New member
May 22, 2022
3
Yorba Linda, California, 92886
Pool Size
23000
Surface
Plaster
Chlorine
Liquid Chlorine
Greetings, please bear with me, new at this.

TFB Membership
I joined TFB in May 2022. as Gene 1939
I followed various topics on TFB regarding pool issues that I was having at the time. (See my posting from May 22, 2022.)
However, I became very involved with family issues and had very limited time to maintain and solve pool problems. Until recently.
I am the sole maintainer of my 44 year old pool which I designed in 1980.

SLAM
I printed out and read the TFB SLAM instructions to address the continuing algae issues in my pool.

Brushing and Vacuuming
I vacuum and brush with a large nylon bristle brush and a 4” ss wire brush nearly every day. Problems: algae, stains, calcification.

TF Test Kits
For some time, the TF100 test kit was not available.
But recently, I ordered the kit with the slam option and tested the water on 8/24/24 with following results.:
  • FC <0.5
  • TC <0.5
  • pH 8.2
  • TA 200
  • CH 750
  • CYA 20
TFB Pool Math
The data above were inserted, as well as I could, into the TFB old pool math table with the results shown in the jpeg attached, hope it is easily read..

Pool Math says to apply chlorine, acid, and CYA. And to remove 20 % of the pool water. I have not yet acquired the CYA.

Metal Stains
In May 25, 2024, stains appeared on the walls and floor of the pool. I suspected they were copper stains. Occasionally I had applied ~ 3 oz of copper pentahydrate crystals to kill off algae at the recommendation of a water chemist.
At that time, I suspected the clarifier, and algae guard that I had been using and latent copper in the water had created the stains.
So, I recently tested two stain spots on the floor of the pool with vitamin C pills (ascorbic acid). In both instances the pills, once dissolved, lifted some of the stain.
I have since stopped using Algae Guard. Brushing with nylon bristle or wire brushes does not lift the stains. And the stains appear to be getting worse.

If the pool is treated with ascorbic acid , or other acids, ultimately the water must be removed to eliminate the copper ions in the water. Adding a sequestrant does not seem to be a good solution.

Calcification
Some of the observed algae is trapped under a layer of what appears to be calcification. This is seen at the tile water line. It is not removed easily with a wire brush, but can cleaned with a stone.

So my Question Is: SLAM for algae versus Stain Removal?
Continuing with algae reduction requires 20% of the water to be removed. On the other hand, all of the water would be removed to eliminate the copper. What is the best approach?
Additionally, would the stains be better removed with an MA wash? Calcification points?
I appreciate your comments, Thank you for your efforts.
Gene
 

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Gene, copper is a troublesome item to remove, and yes, if you can exchange water to remove the copper that is best. Keep in mind the only reason the Poolmath is recommending you to exchange water is because of the elevated CH level (scale). If you wanted to perform the SLAM now you could by increasing the CYA to 30 and maintaining the FC level of 12.

In the long run (ideally) you want to ensure there is no copper. Copper stains removal via a sulfamic acid treatment coupled with a huge water exchange would be best. Refer to the link below for more info about sulfamic acid.

Weather may be a factor. I was at Beale AFB for several years, are you from that Yuba City/Linda area? You might want to wait until the water temps drop to 60 degrees or lower before trying the stain treatments as they often require zero FC and you don't want to get algae. So you could get rid of the algae now via the SLAM Process, then treat for copper in the winter, but that's totally up to you.

As for your old profile, I'll ask @Leebo if they should be combined or just leave alone.

 
As for your old profile, I'll ask @Leebo if they should be combined or just leave alone.
He's still him. (y) This is his original post



Welcome back Gene !!!
 
Hello Texas Splash,
Thanks for your prompt response on the issues I posed and the link to sulfamic acid. I will enlighten myself on the chemistry of the article.
I live in Yorba Linda which is near Anaheim in SoCal. The temperatures here have been in the 90s this August, making the algae problem worse.
If in the end, I would have to dump a lot of water to rid the pool of the copper, I thought it might be best to do that right away. But your comment on a lower temp for the stain treatment delayed to winter is one that I wasn't aware of. More to think about.
Since I wrote my TFP posting I looked into other alternatives to the stains:
#1 Pool Sanding. You recall that my pool was built in 1980. And that it was re-plastered 15 to 20 years ago. The re-plastering was not done well. It is rough and bumpy.
It is in those places that the stains reside. Back in the late 80's, I hired a pool service to sand the original plaster as it was recommended back then. It worked well.
Did a search on pool sanding and didn't find people who offer that service. However DRP Tools makes sanding wheels for the purpose of pool plaster smoothing, and has a description of the process on the web page.
#2 Acid Wash. There are a number of companies in the area that will provide MA washing services. On the down side of that is the affect on the plaster if it is too old. Haven't got any quotes on acid washing but estimate it might be ~$700.
A few months ago I got a quote to have the pool re-plastered. With all the bells and whistle items he thought necessary, his estimate came in at ~$29K. Too expensive for us.
Don't expect to be using the pool so much anymore. Wife and I are both 85.

Any more thoughts or comments? (Attached is a photo of the pool and spa from 2021. Notice the tethered floater above the deep end for the stabilized 3" trichlor pucks. Gave up on those due to expense. )

Thanks again. Gene
 

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