Rough and Discolored Pool Plaster - Why and how to fix?

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Rancho Cost-a-Lotta said:
Keep your CSI in the 0.0 to -0.30 range.
Click to expand...

To get rid of calcium scale drive your pH and CSI lower.

Lower your pH to 7.0 and try and maintain it there. Your CSI may get down to -0.6 or even -1.0 for a while to dissolve the scale.
 
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I just wanted to update this thread...

I've been keeping the pH between 7 to 7.4 and keeping the chlorine pretty low... but the scale is getting worse and it's spreading. I guess I'll just have to deal with it this summer and maybe drain and acid wash the pool next year unless anyone has any other suggestions for me.
 
You PoolMath logs have not been updated in 10 months.

Post a complete set of current test results.

What is your CSI with your pH at 7.2?
 
ajw22 said:
You PoolMath logs have not been updated in 10 months.

Post a complete set of current test results.

What is your CSI with your pH at 7.2?
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FC 8
CC 0
CYA 50
pH 8ish
TA 70
CH 570

CSI .44 (currently)
CSI -0.32 (if pH were at 7.2)

Crazy that the pH is so high as I've been monitoring and for the last week and a half it hasn't been above 7.4... but I did just put a gallon of chlorine in about 2 hrs ago.

I put a half gallon of muriatic acid in just now because of the high pH and will check pH in a couple of hours to make sure.
 
Palpatine said:
FC 8
CC 0
CYA 50
pH 8ish
TA 70
CH 570

CSI .44 (currently)
CSI -0.32 (if pH were at 7.2)

Crazy that the pH is so high as I've been monitoring and for the last week and a half it hasn't been above 7.4... but I did just put a gallon of chlorine in about 2 hrs ago.

I put a half gallon of muriatic acid in just now because of the high pH and will check pH in a couple of hours to make sure.
Click to expand...

PH is 8-ish? Meaning its off the scale too high? Or between 7.8-8.0?
 
So your CH rose by 200 ppm in 10 months. You will need to drain your pool to lower your CH sometime in the next year.

What is the CH of your fill water?

Marty may have some ideas on how to manage your water chemistry @mknauss
 

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ajw22 said:
So your CH rose by 200 ppm in 10 months. You will need to drain your pool to lower your CH sometime in the next year.

What is the CH of your fill water?

Marty may have some ideas on how to manage your water chemistry @mknauss
Click to expand...
I did add calcium during the startup... and at another time but I don't have the records.

I'll check my fill water for CH but I think it's around 350ish... but I'll post shortly after I check pH again.
 
With fill water at 90 CH, you should be pretty good for some time. Try to use rain water to refill pool when you get.

I would suggest starting to use CSI for chemistry monitoring as your current CH is getting on the higher end of the normal scale.
 
mknauss said:
With fill water at 90 CH, you should be pretty good for some time. Try to use rain water to refill pool when you get.

I would suggest starting to use CSI for chemistry monitoring as your current CH is getting on the higher end of the normal scale.
Click to expand...
Thanks for your response @mknauss . We don't get a lot of rain where I'm at and it gets pretty darn hot. I already fill about 5 min of water (line goes directly to the pool) about once every 2-3 days.

Do you think I'm fine where I'm at? The scale (stain on the bottom of the pool) seems to be getting worse and it's spreading. I'll stay on top of the pH and CSI but do you think I'd be better of doing a partial drain?

Thanks
 
At a CH of 570 (how did you test that? Normal results are in factors of 25) you are not in scaling region. If you drained, the lowest the CH should go is 350 ppm. So your stain is not likely to be scale, unless your test results are not accurate.
 
mknauss said:
At a CH of 570 (how did you test that? Normal results are in factors of 25) you are not in scaling region. If you drained, the lowest the CH should go is 350 ppm. So your stain is not likely to be scale, unless your test results are not accurate.
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I just used the regular CH test, filling comparator tube to 25ml... I should probably start only filling to 10ml for the "high" anticipated calcium test in which case it says to multiply drops by 25 instead of 10. Just for a point of reference, I took a sample to Leslie's the other day to test for metals and they measured my my calcium at 458.

My test results should be accurate... I don't see how I could have screwed them up.

What else could the stain be? I slammed my pool a couple of weeks ago and I believe I had ammonia as my CYA was at 0... but metals were in range and my pool is holding chlorine now.

I'm really at a loss here.
 
mknauss said:
Have you tested the stain with Vitamin C? A trichlor puck?
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Yup and yup. At first I thought the trichlor puck worked... but the slam didn't seem to help the stain. The vitamin C test is not easy to perform in the deep end but I didn't see any results... and the Leslie's metals test showed iron at .1ppm and copper at .2ppm.

You're thinking it could be organic, even though I passed the OCLT and water is crystal clear?
 
Unsure. Did you have high CH and/or high pH in the past that might have created the scale? Scale can form with dirt or other organics in it and look like a stain. But the puck should have lightened it as it is acidic and would cut through the scale.
 

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