Calcium Hardness on New Pool

Cayman

LifeTime Supporter
Sep 16, 2008
152
Jacksonville, FL
We just had our pool filled last Friday and I checked the CH mid-week and it was 400. This weekend the CH is 425. The CH of our tap water is 300.

Is this normal to be so high or should we be concerned with a brand new pool? Test results below... I added acid to bring down the TA and PH. Brining PH to 7.0 as we have 3 waterfalls to add aeration to bring PH back up some (per Pool Math app).

Thank you.


FC: 4.0
CC: 0.5
PH: 8.4
TA: 150
CH: 425
CYA: 30
Salt: Off for 1st 30 days
 
Last edited:

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
13,229
Northern NJ
Plaster pool? Vinyl? Please put details of your pool in your signature.

I would not be so quick to lower pH to 7 to lower TA on new plaster. Leave your TA alone for a while.

What startup guide are you following?


  • 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.
 

Cayman

LifeTime Supporter
Sep 16, 2008
152
Jacksonville, FL
Thanks. Looks good and very helpful.
I get my borate strips and thermometer this week, so I will be able to add more information then.

I am not sure what startup method the pool builder used. I know they had a bottle of quick start sequestrate and baking soda and choline tabs. They did have something in ziplock bags that resembled little tiny balls, but they have since taken those.

At this point, should I be concerned with any of my numbers?
 
Last edited:

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
13,229
Northern NJ
What start guide are you following?

Use PoolMath To calculate your CSI. As posted above keep CSI positive for first 30 days.

Why are you thinking about borates now?
 

Cayman

LifeTime Supporter
Sep 16, 2008
152
Jacksonville, FL
What start guide are you following?

Use PoolMath To calculate your CSI. As posted above keep CSI positive for first 30 days.

Why are you thinking about borates now?
I have no idea on the Borates. Its been some years since I have started up a pool and I am finding out a lot of things have slipped my mind since. I guess that happens when you get old like me. LOL
 

Cayman

LifeTime Supporter
Sep 16, 2008
152
Jacksonville, FL
Wait at least a year for you plaster to cure and pH to stabilize then you can assess your need for borates.

Thanks... I do plan on adding, as I did in my last SW pool. I saw a great improvement overall, but good to know that I should wait a year first.

As far as my other chemicals, my CSI is over 1 at the moment and that concerns me. Especially being a new finish. Granted, the finish is only a week old, but I want to make sure I do everything I can to protect it.

Any opinions or advice?
 

Cayman

LifeTime Supporter
Sep 16, 2008
152
Jacksonville, FL
Use PoolMath to determine what pH gives you a CSI around 0.5 and lower your pH using MA.
As I stated earlier... I added a couple of quarts of acid earlier today. I just tested again and here are the results....

FC: 3.5
CC: 0.5
PH: 7.4
TA: 120
CH: 425
CYA: 30
Salt: Off for 1st 30 days
CSI: 0.12

I feel this is a good spot based on being plastered just last week. Agree?