Stubborn battle with greenish spots on walls and floor

nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
Marty... I already did a slam 2 weeks ago but the stains remain. Oclt was 0 for almost a week. So we proceeded to puck testing and now AA (vit c) testing
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,396
Laughlin, NV
Marty... I already did a slam 2 weeks ago but the stains remain. Oclt was 0 for almost a week. So we proceeded to puck testing and now AA (vit c) testing
I am confused - you just stated
I brushed a decent amount of algae from some walls and the floor, but I don't want to add chlorine so that my fc can drop and I can measure ph.
 

nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
I can see how I confused.
After a successful slam, the stains remained. After 2 days or so of the slam, I brushed a light amount of algae from a wall herr and there, but I always maintained my fc high so as to try to combat the stains. I took fc up to 14 and have since, let it drop so as to measure the ph as stated in a previous post. I still brush off a small amount og algae from the walls every other day.

I'm confused as well as to what to do. The slam didn't kill the stains, but it did the algae. After 2 days, I've been battling slight algae and letting g the fc drop to 10.

So,I'm not sure as to how to proceed. Should I slam again? It is a pain. So are the stains, sure.
 

sktn77a

Gold Supporter
May 16, 2010
1,368
Chapel Hill, NC
I'm assuming it's just a stubborn algae. But be aware that if you use ascorbic acid, a high chlorine level will neutralize it. Ascorbic acid is best used when chlorine levels are low.

Did it make any difference?
 
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nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
good morning
I lowered the ph and began the slam process yesterday taking FC up to 24. This morning, oclt = 0, and the water is crystal clear as it has been for months (that was never the issue).
The stains remain and brushing over them continues to do nothing.
I know that my water and pool are perfectly clean, and the pool looks amazing. But seeing the stains drives me nuts, and I imagine that if they are stubborn algae, I will always have algae ready to multiply until I eliminate them.

How do I proceed? With the ascorbic acid treatment?? Fill the pool with cement?
 

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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,396
Laughlin, NV
AA treatment is for iron. If iron, it should react to a Vitamin C test. Has that been done? If so, any change in color at all?
 

JamesW

TFP Expert
Mar 2, 2011
16,345
What is the original color of the plaster?

I think that you probably have iron, copper and scale issues.

What are the chemistry readings?

What is the CSI?

Have you used copper?

If ascorbic acid (vitamin C) doesn't work, sulfamic acid might work, but it will lock up the chlorine for weeks.
 
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nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
AA treatment is for iron. If iron, it should react to a Vitamin C test. Has that been done? If so, any change in color at all?
thanks again Marty. I attempted the vitamin c test on Saturday, but I will call it inconclusive or improperly done. Since most of the stains are along the curved union of the wall and floor, the sock wouldn't stay put. In addition, since the stains aren't a super dark color, it might be hard to see an effect. Perhaps my eyes saw a change last Saturday because my eyes wanted to see a change. In other words, the stains are semi-faint, and I don't know if the vitamin C will do a white out effect.

I will redo the vitamin C test this week and hope to get a conclusive result.
 

nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
What is the original color of the plaster?
I think that you probably have iron, copper and scale issues.
What are the chemistry readings?
What is the CSI?
Have you used copper?
If ascorbic acid (vitamin C) doesn't work, sulfamic acid might work, but it will lock up the chlorine for weeks.
thanks James. the answers:
White
fc 12, cya 60, ta 70 and ch 250. Those were taken Saturday. Today, ph is 7.2 and FC is 24
CSI? I don't know
I have not used copper. I have a sprinkler head that uses well water semi close to the pool, and occasionally some water lands in the pool because of wind. I haven't used the sprinkler in 3 months because of the rains.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,396
Laughlin, NV
CSI? I don't know
You are using Poolmath, though not storing your test data. Be sure to save your test data by touching the check mark on the data entry page.
CSI can be enabled in Poolmath. Go to Settings and enable it. It is calculated by Poolmath. You do need a water temperature for accurate information.
 

JamesW

TFP Expert
Mar 2, 2011
16,345
Is the pool painted?

When was the pool plastered?

I think that you have copper, scale and iron.

Sulfamic acid might work but it locks up the chlorine for weeks.
 
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nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
You are using Poolmath, though not storing your test data. Be sure to save your test data by touching the check mark on the data entry page.
CSI can be enabled in Poolmath. Go to Settings and enable it. It is calculated by Poolmath. You do need a water temperature for accurate information.
I just saved the results, but it didn't calculate the CSI. I entered the numbers into the webpage, and CSI = -0.62

Is the pool painted?
When was the pool plastered?
I think that you have copper, scale and iron.
Sulfamic acid might work but it locks up the chlorine for weeks.
the pool was resurfaced a year and a half ago, and it is not painted.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,396
Laughlin, NV
I just saved the results, but it didn't calculate the CSI. I entered the numbers into the webpage, and CSI = -0.62
Touch the Gear icon in upper right and go to 'What do you want to track?'. Select Track CSI

A CSI of -0.62 is too low. You are in the zone of etching your plaster.
 
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nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
Touch the Gear icon in upper right and go to 'What do you want to track?'. Select Track CSI
A CSI of -0.62 is too low. You are in the zone of etching your plaster.
I do have that selected.
In seeing how to change csi, I entered a current ph of 7.5, for example, and the csi jumped to -0.35. But, my ph is at 7.2 because of the slam, so once the slam officially comes to a close, my ph will rise, and thus the csi will increase.
 

nabril15

Bronze Supporter
May 22, 2011
395
Miami, FL
A small update. The stains remain but the water looks gorgeous. I dropped some vitamin c pills into spots this morning, and went to do other things. Upon my return an hour or so later, i had dark brown spots under each pill. %hit!! What did I do? Thankfully, when the pump kicked on, they slowly went away.
I then got in the water with a regular kitchen sponge, and gently scrubbed 1 stain. Gone. I repeated this throughout, and the stains are 98% gone. Wow. With a sponge? I was careful to not scrub too hard, but it seems to have worked.
 

JamesW

TFP Expert
Mar 2, 2011
16,345
It's probably copper. Ascorbic acid can sometimes work but it can sometimes make new stains that might not come off.

Ascorbic acid is a risk. It might work or make things worse.

Sulfamic acid would probably work but it locks up the chlorine for weeks and the copper is still in the water and can redeposit.