New Plaster Pool

[titleistseemore]

I need some reassurance and have some questions, but first I became a Gold Supporter this week of which I am proud to support TFP, I have received allot of help from these forums. I do allot of reading to find the answers by researching previous post, so even when I do not post a question, I am still getting TFP help. Big Shout Out to the Mods and Experts on the forums, Texas Splash, Newdude, Kimkats, JoyfulNoise, Mknauss, HermanTx, ajw22, and Flyingtivo to name a few, There are many more and thanks to all the members for your insights, it is much appreciated!!!!!

I have been following the NPC startup procedures and have been concerned about CSI, which I will list here ...
TA: 80 to 100
PH: 7.02 to 7.6
CH: Minimum 200
CYA: 30 to 50
FC: 1.5 to 3

When I am at or near these numbers my CSI runs slightly negative -.4 to -.3 ish.

Here are my latest test results:
TA: 80
PH: 7.5 (After adding Acid)
CH: 225
CYA: 50
FC: 10.0 (The free 30 day pool service added 1/2 gallon yesterday)
Temp: 72
CSI: -0.37

1. I have read here on the forums that new plaster needs to have a CSI in the positive range.

2. My PH continuously climbs, I understand this is normal with new plaster up to 18 months after, I did change the pool returns so that they were not breaking the water just pushing the top of the water (Was thinking Aeration was happening), was also thinking I need to let my TA lower to the 60 to 70 range and maybe that would help as well.

3. Calcium Hardness: I have added calcium to get to 225 but think I should increase this (Perhaps this would help my CSI increase) to 350.

When my PH raises to above 7.8, my CSI is positive. Just concerned about the CSI with the new plaster. I have been doing allot of reading here on the forums about scaling etc and do not want to have problems down the road that I could have fixed now!

As always I look forward to your help.

Thanks
Tim

 

[Newdude]

There are many more and thanks to all the members for your insights, it is much appreciated!!!!

We are always glad to help, THANKS for your support. It buys more time that we will be here to help.

1. I have read here on the forums that new plaster needs to have a CSI in the positive range.

Hang tight. I speak vinyl and CSI is Greek to me.

2. My PH continuously climbs, I understand this is normal with new plaster up to 18 months after, I did change the pool returns so that they were not breaking the water just pushing the top of the water (Was thinking Aeration was happening), was also thinking I need to let my TA lower to the 60 to 70 range and maybe that would help as well.

It is certainly worth a try.

3. Calcium Hardness: I have added calcium to get to 225 but think I should increase this (Perhaps this would help my CSI increase) to 350.

What's your fill CH ? If it's higher, you'll get to where you want to be soon enough, and adding now only makes it that much sooner that you'll need to drain to lower it. I'm assuming you get little rain in a sunny part of CA. Some of us rarely need to add water so that's less of a concern if our CH is high from the tap.

When my PH raises to above 7.8, my CSI is positive. Just concerned about the CSI with the new plaster. I have been doing allot of reading here on the forums about scaling etc and do not want to have problems down the road that I could have fixed now!

No matter what, you're light years ahead of the bulk of the population asking Leslie's (etc) what to do, or blindly letting the pool person do it for them.

 

[HermanTX]

need some reassurance and have some questions, but first I became a Gold Supporter this week of which I am proud to support TFP, I have received allot of help from these forums. I do allot of reading to find the answers by researching previous post, so even when I do not post a question, I am still getting TFP help.

Thanks for your support.

This is an excerpt from the Wiki on plaster which you may have already read.
The CSI is not applicable to new plaster finishes under 30 days old. It is actually necessary, to achieve a smooth and dense surface, to have about a +0.5 CSI during the first 30 days. This is because the plaster (cement paste) surface contains about 20% calcium hydroxide, which is somewhat soluble in balanced and slightly positive CSI water and can be dissolved away. The plaster surface needs to be "carbonated" before the CSI should be lowered to the acceptable and balanced range. And that generally is achieved during the first month under balanced water

Plaster Start-Up Guides - Further Reading

www.troublefreepool.com

The water temperature is working against you as cooler water lowers the CSI (makes it more negative). Also, I would let the pH drift up to 7.8 as that will move CSI towards 0. While increasing CH has some positive effects do not let rise too quickly the first 30 days.

EDIT - also good article
Calcium Saturation Index (CSI)

 

[titleistseemore]

My initial fill CH is 25, we have soft water here. How high can I or should I let the PH rise without it being a problem. No one will be swimming in the pool, but the Spa will be used occasionally on weekends.

This is an excerpt from the Wiki on plaster which you may have already read.
The CSI is not applicable to new plaster finishes under 30 days old. It is actually necessary, to achieve a smooth and dense surface, to have about a +0.5 CSI during the first 30 days. This is because the plaster (cement paste) surface contains about 20% calcium hydroxide, which is somewhat soluble in balanced and slightly positive CSI water and can be dissolved away. The plaster surface needs to be "carbonated" before the CSI should be lowered to the acceptable and balanced range. And that generally is achieved during the first month under balanced water

I had not read this ... So, I need to get to +0.5, Below is a test result from 11/12/2022 where I had a CSI of +0.77
FC: 2.0
PH: 8.6
TA: 100
CH: 200
CYA: 50
Temp: 70
CSI: 0.77

The PH made a big difference, but I was worried about the NPC start up guidelines that states to keep PH between 7.2 to 7.6. Link below to the NPC start up guidelines. I added acid and bleach after my 11/12 test results to increase FC and lower PH.

https://finestfinishpools.com/wp-content/uploads/2022/08/npc-pool-start-up-english.pdf

I raised TA with baking soda, but it has been dropping slightly with the acid additions but will let it drop further to possibly help with the PH drifting upwards too quickly. Thinking a TA of 70 (Midpoint of the ideal range of the app.)

I had gone from 200 to 225 on CH by accident, was tired and at the time was raising my CA from 20 to 50 and accidently grabbed the wrong tub thankfully I was doing small additions and caught it quickly (I was kicking myself on that one) My thoughts again after playing around with the App, keeping everything the same and just raising the CH I can get to a higher CSI, My accidental increase in CH was 11/13 The MPC guidelines state bring to a minimum of 200 so I was thinking of raising CH to help with the CSI.

After 28 days the NPC states "The Langelier Saturation Index (LSI) must be maintained between 0.0 and +0.3 for ongoing maintenance, especially within the first six months after the initial start-up, to avoid potentially serious damage to the interior finish surface"

Doing this to be in guidelines of warranty and most important to have an interior finish that will last a long time.

Thanks
Tim

 

[titleistseemore]

I went ahead and added Calcium, will test and see where the pool is in about an hour

 

[Newdude]

How high can I or should I let the PH rise without it being a problem.

For Ph itself, any 7 is equally fine. Step in at 8 or 8.2 if you don't catch it immediately.

That's providing the CSI agrees without being too far out of whack. Some folks have to target a smaller range than just a 7.

 

[HermanTX]

How high can I or should I let the PH rise without it being a problem. No one will be swimming in the pool, but the Spa will be used occasionally on weekends.

If you test and the pH is at 8 or 8.2 (or higher) bring it down to 7.6-7.8 as that helps offset the cold-water temperature effect in the CSI calculation. I gave a range because do not want to drive you crazy hitting an exact value. Same with CSI. Be in the range. To have any detrimental affect you have to be either very positive or very negative for several months at a time.
I would suggest testing every 2nd day during this first 28 day period just to stay on top of it and it helps you understand the dynamics.
The TA in range of 70-80 is fine as well.
Just remember in our testing - for TA 1 drop is 10ppm, for CH 1 drop is 25 ppm - so it can fluctuate just due to testing and you are learning. You are gaining experience each time you test.

Having your CYA at 50 is fine. just hold it there for now.
You are doing great.
There are some differences between CSI and LSI

CSI and LSI - Further Reading

www.troublefreepool.com

 

[titleistseemore]

New Test Results:

FC: 10
PH: 7.8
TA: 100
CH: 275
CYA: 50
CSI: +0.11
Temp: 70

I had added 8 lbs. of calcium.

The TA went higher could just be that I tested indoors instead of outside under daylight. I keep reading to keep the CSI positive for new plaster, Should I keep slightly increasing Calcium to 350? Should I lower TA to 70 by adding acid and then aerating (I put in deck jets with that idea in mind as well as my wife wanted a water feature other than the waterfall from the raised spa, we wanted a waterfall in the corner however there is a PU easement that would not allow it by code).

 

[HermanTX]

New Test Results:

FC: 10
PH: 7.8
TA: 100
CH: 275
CYA: 50
CSI: +0.11
Temp: 70

I had added 8 lbs. of calcium.

Looks great. Continue to monitor pH and TA. You may see your TA come down slowly as you cycle pH.
I would not add any more calcium chloride.