Remove stains from plaster pool

TurboMatt

Member
Apr 11, 2019
21
Frederick Maryland
After several weeks, my pool water is finally looking good! All of the water chemical levels are excellent, per my test results and the local pool supply. Anyway, I'm now left with stains all over the plaster floor and part of the walls. What are my best options to help alleviate some of the staining without draining the pool? I would like to put off draining the pool until fall, if possible.

This is what I started with.

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This is how things look as of this morning.
 

TurboMatt

Member
Apr 11, 2019
21
Frederick Maryland
Thanks for the link. I recently purchased the house and can only assume they are organic. I removed 4-5 wheel barrow full of leaves, sticks, etc from the pool when I initially opened it. So that had been sitting at the bottom of the pool for several years.
 

TurboMatt

Member
Apr 11, 2019
21
Frederick Maryland
How high is 'elevated'?

I've also read about lowering PH levels for a week or so will help to "acid wash". The water would obviously be un-swimmable but is that a suitable option?

 

Mr Bruce

TFP Guide
Mar 24, 2014
2,338
Greenville, SC
Somewhere between the top of your target FC and SLAM FC.

I would not recommend holding the pH artificially low for a week. Just raise the FC and they will go away. Pool Owner Patience! :)

If there are particularly "bad" spots you can put a puck on them for 15-30 minutes and it will go faster.
 

TurboMatt

Member
Apr 11, 2019
21
Frederick Maryland
I am completely fine with it taking time. My concern is basically the best way to alleviate them. So if shock is around 10-12 ppm, should I plan to keep the CL around 6-8 ppm?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
6,700
Northern NJ
I am completely fine with it taking time. My concern is basically the best way to alleviate them. So if shock is around 10-12 ppm, should I plan to keep the CL around 6-8 ppm?
I would go 6-9 ppm. You want to keep FC below 10 ppm as pH test becomes unreliable after 10 ppm.
 

Mr Bruce

TFP Guide
Mar 24, 2014
2,338
Greenville, SC
Vitamin C tablets are for metal stains, puck/elevated FC are for organic stains. Seeing that TurboMatt posted that there was leaf debris on the bottom of the pool and looking at the video, it's very very likely organic staining. Vit-C won't hurt anything to try, but I'll bet it's not going to do anything.
 

jimim

Bronze Supporter
Jun 20, 2016
2,299
NE/Pa
If that worked I would do as others r saying and sit back and relax. If u leave the puck on too long u can hurt the plaster also. I would just raise the fc level. At least that way u are also keeping the pool water clean also.