Lowering Total Alkalinity

[elyders]

My 15,000 gal gunite pool is 1 week old and the total alkalinity is still too high. It started at about 320, now it's at 210. Should I be in panic mode? Will my plaster start getting rough?

Is this normal for a new pool? I brushed 1-2 times per day for a week, and have an in-line chlorinator with tri-chlor tablets.

Here's the other numbers (I only have the Pentair 5-in-1 test):

chlorine: somewhere between 1.5 and 3.0
pH: 7.6
TA: 210

My manual from the test kit says to add acid to lower the TA, but won't that also lower my pH? How do I lower the total alkalinity without lowering the pH?

[mas985]

Normally, for a new plaster pool, you want to keep your PH low but above 6.8(6.8-7.2) until all the plaster dust is gone (1-2 weeks). This will also lower your total alkalinity. Also, Ben has a good procedure for lowering alkalinity:

http://www.poolforum.com/pf2/showthread.php?t=191

[elyders]

Thanks for the link to the thread.

I'm a little concerned about messing with the TA because my chlorine and pH seem good and my water is clear.

I read on www.askalanaquestion.com that "There is no compelling reason to have to lower the TA, once the pH is in range and there is no sign of scaling or cloudy water."

Is that true? Does the TA really not matter as long as everything else is OK?

[mas985]

Well, do you want to wait until there is scaling or prevent it? Higher alkalinity increases the probability that you will have some scaling (depending on your calcium hardness). In addition, higher alkalinity makes it harder to change your PH when you need to.