amount of CYA in trichloro granules

[flash]

I finally opened my pool. I added 3 - 182oz jugs of bleach (all that I had). I have about 30 lbs of the OPTIMUM Chlorinating Granules (from wal-mart or lowes made my aqua-chem) left over from last year before I started the BBB. Since my CYA values are 0 (or 9 according to the pool store), I thought that I might use the Chlorinating Granules until my CYA values go up.

According to chem geek, raising FC 10 ppm also raises CYA 6 ppm. Is this relationship for any trichlor? or is it just for the tabs? or the available chlorine?

The granules are:
Active Ingredients:
trichloro-s-triazinetrione 71.8%
Boron sodium oxide pentahydrate 8.0%
Other Ingredientsclarifier/filtration enhancer/sunlight protector 20.2%
*Available Chlorine 65%

I guess that I could use them and test the CYA each week, but to me, the CYA test if the hardest to read.

 

[chem geek]

That relationship holds for any Trichlor product regardless of concentration or of pool size, BUT the product you show says it has 20.2% "clarifier/filtration enhancer/sunlight protector" so it is possible that the "sunlight protector" is additional pure CYA. In the worst case, if that was 20.2% pure CYA, then for every 10 ppm FC you'd get 6.1+6.1*20.2/71.8 = 7.8 ppm.

 

[flash]

thanks chem geek. After playing with the pool calculator, and seeing how much the trichlor affects not only CYA, but also pH, I don't think that I would save that much money using the trichlor I already have.

 

[chem geek]

You are right. As described in this old post Trichlor actually costs more than chlorinating liquid or bleach or Cal-Hypo when one accounts for the chemicals needed for pH adjustment (even using Arm & Hammer Super Washing Soda which is less expensive than pH Up).