Chronic low chlorine

[willrice]

FC 0.23
TC 1.29
pH 7.6
TA 145
CA 96
CYA 40

Please help! My chlorine levels are consistently low after adding the Pool Calculator's recommended amount of bleach. The results I'm getting are consistent with pool store analysis. The water appears clear and clean.

How does an inline chlorinator figure in to the BBB method? I've also attempted raising chlorine level by increasing dial flow on the chlorinator.

Thanks from a beginner :-D

 

[JohnT]

When you can't get chlorine to stay in the pool, it's usually a result of low CYA or algae. Your CYA is reasonable, and with chlorine that low, you almost certainly have algae in the pool. If you'll raise the chlorine to shock level for your CYA level (see Chlorine CYA Chart ). Follow the process at Shocking Your Pool

and keep it there by testing and dosing every few hours for a few days, you'll probably see your chlorine demand drop.

 

[RobbieH]

FC of .23 and TC of 1.29 is indicative of algae being in the pool. Time to go through the shock process: pool-school/shocking_your_pool

Those look like pool store numbers, not numbers from a FAS-DPD test.

 

[JasonLion]

If your numbers are correct, you have CC of 1.06, which means you need to shock the pool.

There are several possibilities. You might have underestimated the size of the pool. You might have algae consuming some of the chlorine. You might have ammonia in the pool using up chlorine. Your chlorine source might be weaker than you think it is. Your ColorQ might not be working right (less likely, but possible).