CYA Help

[Desperado13]

Newbie here to the Diclor-Bleach Method. Can you all make sure I have my head wrapped around this correctly.

I believe I am ready to switch to bleach. I have trouble accurately reading the CYA test (TF-100) so I have calculated based on the amount of diclor I have added. So far, I have added 3.2oz of diclor. It takes 0.8oz to increase my FC to 10ppm so it is a factor of 1.2. So, I have added about 38ppm of CYA. Is that right?

 

[Rancho Cost-a-Lotta]

Welcome!
The numbers above don't make sense in terms of dichlor additions for a swimming pool. Dichlor does contain both chlorine and CYA (cyanuric acid), but it would take much more dichlor to result in a CYA increase of 38 ppm. As I give you a bump, post a set of test results in the format below and let us know what you're trying to accomplish. Help will come.

FC - Free Chlorine
CC- Combined Chlorine
pH
TA - Total Alkalinity
CH - Calcium Hardness
CYA - Cyanuric Acid (stabilizer/conditioner)

Also complete your signature so we can answer questions related to your pool:

Please include the following information:

• The size of your pool in gallons
• If your pool is an AG (above ground) or IG (in ground)
• If it's IG, tell us if it's vinyl, plaster/pebble, or fiberglass
• The type filter you have (sand, DE, cartridge)
• If you know, tell us the make and model of your pump and filter.
• List other known details of the pump - Horsepower, Single speed, 2 Speed or Variable Speed
• List any other equipment you have: SWG, second pump, etc.
• List what test kit you use to test your water
• Please mention if you fill the pool from a well or are currently on water restrictions

Best of luck!

 

[duraleigh]

OP is discussing his spa, I think.

 

[mknauss]

In Poolmath, you can use Effects of Adding Chemicals.
In a 350 gallon water volume, 3.2 oz of Dichlor will add 35 ppm CYA.

 

[Desperado13]

Mknauss,
Thanks for pointing out the “effects for adding” - that makes it much simpler. I have added details to my signature now. I’m so appreciative for this forum.
At least it confirms my calculations - I’ll switch to bleach now. I’m going to keep trying the CYA test - maybe practice helps.

 

[Rancho Cost-a-Lotta]

OP is discussing his spa, I think.

I see. I guess I should have looked at the forum section. Thank you.