Carbonate Alkalinity

[MA5177]

I’m starting up a freshly plastered pool, and the instructions on day 4 say to test my CARBONATE alkalinity. What is that? How do I test that with my TF kit?

 

[Newdude]

It’s a fancy way of saying to test your calcium hardness (CH). Too little and the water will suck it from the plaster. Too much and you will get Calcium scale on the finish and inside the plumbing/equipment.

Amazon sells it in bulk. You want pure Calcium Chloride with no additives

See Recommended Levels and download the poolmath app for free to figure out how much you’ll need based on your TF-100 results.

 

[mknauss]

The following article provides a description of alkalinity.

TA - Further Reading

www.troublefreepool.com

 

[MA5177]

It’s a fancy way of saying to test your calcium hardness (CH). Too little and the water will suck it from the plaster. Too much and you will get Calcium scale on the finish and inside the plumbing/equipment.

Amazon sells it in bulk. You want pure Calcium Chloride with no additives

See Recommended Levels and download the poolmath app for free to figure out how much you’ll need based on your TF-100 results.

Ok it threw me for a loop because it said to test for that then it says to test for CH

I have the pool math app, but trying to follow the builders guidelines from the national plaster council

 

[JamesW]

Carbonate alkalinity is the adjusted alkalinity as described in the TA page.

Calcium hardness is not the same thing as carbonate alkalinity.

Just try to keep the CSI between -0.3 and 0.0.

 

[Newdude]

Calcium hardness is not the same thing as carbonate alkalinity.

My bad. Google said that’s how it was tested.

*edit. Ahem. Excuse me. Google put me in touch with THREE blog sites that even though they agreed, I knew better than to trust, not being here.

 

[MA5177]

Carbonate alkalinity is the adjusted alkalinity as described in the TA page.

Calcium hardness is not the same thing as carbonate alkalinity.

Just try to keep the CSI between -0.3 and 0.0.

This is the guidelines they recommended, anything different I should do this is freshly plastered a couple days ago.

As of this morning my Ak was 120 and PH was about 7.6 so I added more acid. CH was 250

No chlorine or CYA added yet

 

[JamesW]

Mostly just brush daily and maintain the CSI between -0.3 and 0.0.

 

[JamesW]

Calcium hardness and total alkalinity are both reported in units of "calcium carbonate" equivalent.

So, that can create some confusion.

For example, if you added calcium carbonate to the pool, the calcium hardness and the total alkalinity would go up by the same amount.

 

[Newdude]

So, that can create some confusion

Thanks, but I still fell for the classic blunder. I might as well have messed with a Sicilian when death was on the line.

 

[MA5177]

My pool is 3 days old plaster and I’m having trouble getting the alkalinity down to 80, currently about 110. I’ve been adding acid every day to get the PH down but it’s not working very well. Any suggestions? How much can I add at once? 13,500 gallon pool.

 

[mknauss]

When your pH tests at 7.8 or higher, lower it to 7.4 or so. This will be a common occurrence (daily) at the start up of new plaster.
TA will take care of itself.

 

[JamesW]

How much can I add at once? 13,500 gallon pool

Are you using pool math to do the calculations for how much acid to use?

Also, use poolmath to calculate the CSI.

PoolMath

Discover the calculator behind the perfect pool, PoolMath. Dealing with pools has allowed TFP to become the original authors of the best calculator on the net.

www.troublefreepool.com

 

[JamesW]

Put in your starting pH and the target pH and make sure that the pool volume and the TA are entered and it will tell you how much acid to use.

 

[MA5177]

Mostly just brush daily and maintain the CSI between -0.3 and

Are you using pool math to do the calculations for how much acid to use?

Also, use poolmath to calculate the CSI.

PoolMath

Discover the calculator behind the perfect pool, PoolMath. Dealing with pools has allowed TFP to become the original authors of the best calculator on the net.

www.troublefreepool.com

Yes pool math... for AK all it says is “lower PH to 7.0-7.2

 

[JamesW]

Yes pool math... for AK all it says is “lower PH to 7.0-7.2

Correct, just keep adding the correct amount of acid to lower the pH and the TA will be fine.

What is the current CSI?

As long as the CSI is not over 0.2, there's no rush to lower the TA.

If the pH is in the 7.2 to 7.4 range, the CSI should be good.

 

[MA5177]

Correct, just keep adding the correct amount of acid to lower the pH and the TA will be fine.

What is the current CSI?

As long as the CSI is not over 0.2, there's no rush to lower the TA.

If the pH is in the 7.2 to 7.4 range, the CSI should be good.

Ok thanks, as of last night these were my readings

 

[JamesW]

Ok. The CSI is the key. Keep that right and you are fine.

 

[MA5177]

Ok. The CSI is the key. Keep that right and you are fine.

Can you briefly explain what CSI is and how it affects your pool?

 

[JamesW]

Can you briefly explain what CSI is and how it affects your pool?

A CSI of 0.0 means that the saturation of calcium carbonate is perfect. Not too high or too low.

It accounts for all of the chemistry at once to find the perfect balance.