No drain acid wash

Maddie

Active member
Feb 18, 2010
39
South Alabama
Pool Size
11000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
A pool service tech is telling me the stains on my 12 year old pool plaster is scaling and an acid wash using muriatic acid would help! Is there step by step instructions on here somewhere? I just want to double check what he’s telling me is correct! He said put 7 gallons of muriatic acid to my (11,000 gal) pool and a bottle of metal out. Keep the filter running on high 24/7 for 5 days. And brush the plaster at least twice daily. Then balance the chemicals back afterward. Does that sound right?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
18,592
Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
That is not right. 1 gallon of acid on your pool will lower the TA by 46ppm. 7 gallons would send the TA negative (consumes 319ppm of alkalinity), would crash your pH to below 2 and very likely damage your plaster. That much acid would make your plaster rough and porous which will only lead to more staining and a weaker surface. You will also damage your SWG with that low of a pH not to mention any metal components in your pool.

Do NOT follow that advice. You will wreck your pool.
 

ferretbone

In The Industry
May 24, 2016
161
tx
Yeah 7 gal is kinda crazy for 11,000. Turn your equiptment off. Use two bottles and brush with a wire brush for three or four days. Bring the ALK and Ph back up and start your pump.
 
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Maddie

Active member
Feb 18, 2010
39
South Alabama
Pool Size
11000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
Yeah 7 gal is kinda crazy for 11,000. Turn your equiptment off. Use two bottles and brush with a wire brush for three or four days. Bring the ALK and Ph back up and start your pump.
Thanks! He also told me to run my pump while doing it! 😳
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
18,592
Tucson, AZ
Pool Size
16000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Before you do anything, please post a full set of chemistry test for the water and pictures of what it is you are trying to get rid of.

I would recommend you wait until other experts have had the chance to look at your pictures. A Zero Alkalinity treatment is not without danger to your plaster and you do not want to do one without good reason. The amount of time you wait is not a set thing. It’s based on what you see visually and I would never recommend going longer than 24 hours unless you see actual progress in the stain removal. If nothing happens in the first few hours then the treatment should be immediately terminated to avoid damage.
 
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Maddie

Active member
Feb 18, 2010
39
South Alabama
Pool Size
11000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Turbo Cell (T-CELL-5)
Before you do anything, please post a full set of chemistry test for the water and pictures of what it is you are trying to get rid of.

I would recommend you wait until other experts have had the chance to look at your pictures. A Zero Alkalinity treatment is not without danger to your plaster and you do not want to do one without good reason. The amount of time you wait is not a set thing. It’s based on what you see visually and I would never recommend going longer than 24 hours unless you see actual progress in the stain removal. If nothing happens in the first few hours then the treatment should be immediately terminated to avoid damage.
I am still researching it and will definitely post my numbers and pictures soon (hopefully tomorrow)! Thank you!