New pool results

[CarlD]

I think I can answer part of this:
Usually, Ben's recommendation for Total Alkalinity is 80- 125 especially for gunite/plaster pools. Generally, as you know, pH is easier to keep constant when the T/A is at the higher end.

Other than that, I would agree with Chem_Geek's advice to do what the builder says chemically to avoid giving him an excuse to void the warranty.

The Taylor 2006 or 2006c kit is an excellent choice. Equally good is the Leslie's FAS-DPD Chlorine Test service kit, but Leslie's stores rarely sell it. It's available on-line.

The best kit of all is Ben's test kit available at his sister site to this one, PoolSolutions.com. It's ONE BIG problem is that Ben (PoolDoc) hasn't been selling it for awhile, and, until he announces that he's selling and shipping again, it's just not available.

Still, any of these kits will quickly pay for themselves and you will wonder how you ever got along without them!

[ehorn]

Thanks for the advice. I added one gallon of acid to the pool and it changed the results to:

PH: 7.2
TA: 150ppm

I can run the waterfall and spa with spillover to probably lower the TA to a lower value. The only issue I have right now is our waterfall leaks and still waiting on them to fix it. I'm just glad I got the TA down some from before.

I'm also going to pick up a better test kit, any suggestions as to who sells it for a good price online?

Eric

[chem geek]

Eric,

Though you have reduced the measured Total Alkalinity by adding acid, you actually haven't removed hardly any of the carbonate from your pool. My calculations show that simply adding acid to lower the pH from 8.2 to 7.2 will lower the TA from 180 to 157 just by changing the proportion of different chemical species in the water (you shifted to having more carbonic acid, H2CO3, in the water and that species does not count towards TA). If you were to raise the pH even by adding caustic soda / lye (which does not have carbonate), you would raise the TA back up again. pH and TA move up and down together.

This is why adding acid alone does not really lower the TA in an absolute sense. Only the aeration will do that and aerating while at a lower pH gets rid of the carbonate in the water faster. So when you get your waterfall fixed, start aerating while keeping the pH low and that will truly lower the amount of carbonate in your pool.

Richard

[CarlD]

What Richard says is exactly correct. Since you have a gunite pool, T/A levels are more critical than it would be for a vinyl pool (for vinyl your current t/a would be fine).

You need to aerate your water to raise pH without raising T/A. It's a racheting process--lower pH to 7.0-7.2 (with gunite it can be lower, but you have NEW gunite so stay in the range). This pulls the T/A down. Then aerate to raise pH without T/A rising. Repeat until T/A is where you want it, then aerate to raise pH one last time to normal.

Do NOT confuse caustic soda with washing soda. The first is lye, sodium hydroxide, the latter is sodium carbonate, and is the same as soda ash the pool stores sell (actually, it's not the same--it's FAR cheaper!)

And don't confuse either with baking soda, sodium BIcarbonate, which is used to raise T/A, should you need to do so.