I had my pool resurfaced in March of 2019 with QuartzScapes plaster. I have to put muratic acid in every other day. The PH will be a perfect 7.2 when I add the acid but in a couple of days it is above 8(almost purple in test tube). My pool surface has also developed brown stains all over the bottom. All other measurements are in good range. I use only liquid chlorine. The CYA is low, maybe in the 25ppm range. Alkalinity stays around 90, hardness is 220, chlorine is between 3 and 4 ppm. My pool was originally built in 1997 and has been resurfaced only the one time in 2019. The plaster looks way worse now than it did before resurfacing. Any idea what is going on?
PH
- Thread starter kayaycock
- Start date
Gamecocks fan I take it? 
Give us a full run down of test results with that nice test kit you've got there.
FC
CC
pH
TA
CH
CYA
Salt if applicable
What other chemicals have you used?
Do you fill with city or well water?
Have you ever tested the water for metals? If not, take a sample to a pool store and ask them to test for metals. DO NOT BUY ANYTHING (tell 'em you've got some at home) then let us know the results.
Maddie
Give us a full run down of test results with that nice test kit you've got there.FC
CC
pH
TA
CH
CYA
Salt if applicable
What other chemicals have you used?
Do you fill with city or well water?
Have you ever tested the water for metals? If not, take a sample to a pool store and ask them to test for metals. DO NOT BUY ANYTHING (tell 'em you've got some at home) then let us know the results.
Maddie
As to the pH - new plaster has to cure and it can take months. If you're running any water features such as fountains or spa overflows, that also will act to raise your pH.
Two of the 4 kids are gamecocks! One is a wolfpack and the other is a private school. Hubby is a wolfpack so we are a house divided!! Now we have a grandson at Georgia too!! Thanks for your analysis of this issue. I am at a loss.
FC 4
CC 0
PH 8+(muratic acid or dry acid to pull it down)
TA 90
CH 220
CYA 20
When I refilled the pool in 2019 after resurfacing, I used Aqua Duck and it was a city water supply. The PH was 7 and CYA was 0 going into the pool. I had used stabilized chlorine previously and my CYA had creeped up to 149. So, now I only use liquid chlorine. I put baking soda in about twice a year as the alkalinity decreases over time. I normally add about 20 ounces. I had the water tested for metals in July 2020.
Copper and iron were 0
Phosphate was 294.
FC 4
CC 0
PH 8+(muratic acid or dry acid to pull it down)
TA 90
CH 220
CYA 20
When I refilled the pool in 2019 after resurfacing, I used Aqua Duck and it was a city water supply. The PH was 7 and CYA was 0 going into the pool. I had used stabilized chlorine previously and my CYA had creeped up to 149. So, now I only use liquid chlorine. I put baking soda in about twice a year as the alkalinity decreases over time. I normally add about 20 ounces. I had the water tested for metals in July 2020.
Copper and iron were 0
Phosphate was 294.
Ok, the duck thingie used pucks, right? Pucks are acidic, so that kept your pH in line. And pucks also contain CYA hence I guess that 20ppm CYA.
Do *not* use dry acid with a plaster pool. Dry acid leaves behind sulphates that build up and can wreak havoc on plaster and SWG cells.
In SC you really should have at least 30-40ppm of CYA in the water to help hold on to your FC from day to day.
Recommended Levels
Ignore phosphates.
Can we get a pic or three of the plaster problems you are having??
Maddie
Do *not* use dry acid with a plaster pool. Dry acid leaves behind sulphates that build up and can wreak havoc on plaster and SWG cells.
In SC you really should have at least 30-40ppm of CYA in the water to help hold on to your FC from day to day.
Recommended Levels
Ignore phosphates.
Can we get a pic or three of the plaster problems you are having??
Maddie