liquid chlorine raising pH

[SalvationArmy]

waterbear-
Thanks for your reply. My TA is kept between 70 and 100. I add about 25 gallons of 12.5 % NaClOH / month and about 20 gallons of HCL / month. 50 lbs of sodium bicarbonate is added about once every 5 weeks. That's all I ever add (except for calcium once in a blue moon) so it seems to me that the net change in pH for my pool when adding NaClO is significantly +

[CarlD]

That's gotta be a big pool! Evan gave a really lucid explanation of when to keep TA on the low side and when on the high side--said it better than I could! The Taylor K-1000 OTO/pH test kit uses reagent r-0014 instead of the usual r-0004. r-0014 has a chlorine neutralizer in it so it can accurately read pH at much higher levels of chlorine.

If you need to raise pH AND TA, you can use Washing Soda instead of Baking Soda. Washing Soda is Sodium Carbonate, and is the same as pH Up! and other expensive pool chems, but only costs $.80/lb.

Costco used to sell 12lb bags of A&H baking soda for about $3.50. Yeah, less than 4 bucks for 12 lbs. Don't know what it is now....

Carl

[waterbear]

That's gotta be a big pool! Evan gave a really lucid explanation of when to keep TA on the low side and when on the high side--said it better than I could! The Taylor K-1000 OTO/pH test kit uses reagent r-0014 instead of the usual r-0004. r-0014 has a chlorine neutralizer in it so it can accurately read pH at much higher levels of chlorine.


Carl

So does R-0004. The only difference is the comparator block used with them. The 2000 series comparator blocks for the R-0004 are a higher precision test better suited to commercial pools.

[waterbear]

waterbear-
Thanks for your reply. My TA is kept between 70 and 100. I add about 25 gallons of 12.5 % NaClOH / month and about 20 gallons of HCL / month. 50 lbs of sodium bicarbonate is added about once every 5 weeks. That's all I ever add (except for calcium once in a blue moon) so it seems to me that the net change in pH for my pool when adding NaClO is significantly +

So every 5 weeks you are raising the TA by about 36 ppm (from 70 to a bit over 100, I assume)...As a suggestion only raise the TA to 80 ppm. I think you will find that your acid demand does decrease and if you are adding less acid you will not be 'eating up' TA as quickly. The amount of bleach you are adding is really immaterial here. What you are seeing is the effects of TA on acid demand.

What is your target pH? If you maintain it higher (7.6 to 7.8) you will actually see better pH stability since the lower the put pH the faster pH rises.

[SalvationArmy]

pH is now 7.8 and I have not added any HCL since Sat. Ususally I have to add it almost daily. I am also maintaining CL at a lower level (1-3 ppm) FL code requires a min. 1 ppm CL in commercial pools....


Thanks waterbear!

[waterbear]

I am in FL also and have cared for commercial pools.

It is the individual county Health Depts that set the standards. There really is not a statewide one but from what I have seen they are pretty uniform, at least on the east coast of the state.