Adjusting Total Alkalinity for CYA and Borate

[New2PoolsInAZ]

In the last page of my Taylor K-2006 water chemistry booklet there is a page that explains how to correct the total alkalinity level for both borate level and CYA level. Since I have 30ppm of borate with a PH of 7.6, I have to subtract 5.1 from my TA. For my CYA of 50ppm and given the same PH, I have to subtract about 16.5 from my TA. Thus, it tells me to subtract 21.5 from the TA to get the real TA. The same booklet lists the recommended TA from both NSPF and APSP and TA for pools using Trichlor is recommended to be 100-120. So my target is 110.

That being said, should I take my TA to 126.5 (or close) so it comes to 110 after adjustment? Or do the recommended levels assume the CYA and possible borate? I ask because I am new and every product that recommends a correct TA level never mentions adjustment for CYA or borate but many use those. Other test kits to my knowledge do not mention this either. I asked this in another forum but they said their philosophy was to not worry about TA but just let is go where it goes as you adjust PH. I am new so I do not know what is right, but as there are published levels for TA, I want to know where I fall in those and I am being very careful to get everything adjusted right. (Working the chemistry of this pool, and it's the first pool I have every had and was built this year, has become somewhat of a hobby for me).

[New2PoolsInAZ]

One correction to the above. The borate adjustment is 5.1 and the CYA adjustment is 16.5. So is my accurate TA now 110 (current reading) minus 21.6, previously I said 16.5. The difference of 21.6 makes a huge difference when the recommended ranget is within 20 points (TA of 100-120). Thanks.

[Teapot]

You are worrying a little too much.
Your pebblesheen pool needs a higher TA than a vinyl or glass fiber pool anything around 80-110 would be fine. too higher TA allows for the carbon dioxide to off gas easily raising your pH. You should look at your Langlier saturation index to produce water that is neither corrosive to your pebblesheen or calcium scaling to the surface. Small adjustments in pH have bigger effects of saturation index than playing with TA. Lowering the TA to make (with borates) the pH more stable you can counter any agressive corrosive water by increasing the pH.

When you have CYA in the water the pH doesn't matter provided it's above 7.4. see the paper below.
http://www.poolhelp.com/home/onbalance- ... -efficacy/

[New2PoolsInAZ]

Thank you go much for your reply. I checked the Langlier saturation the other day and found I was at +2 or +3. I will move my attention to trying to get that at 0 rather than worry about the exact TA level. I really do appreciate it.

[New2PoolsInAZ]

Correction, I am at 0.2 - 0.3. Sorry very new at this.