Low chlorine

[K9waves]

DESPERATE

I work with dogs who have mobility issues in an indoor pool. High bather load. 4000 gal. fiberglass pool, 30" filter using filter glass plus UV light.
I have been having a lot of trouble with cyanuric acid build-up, so I decided to switch from tablets to liquid chlorine.
Drained pool and refilled. Added liquid chlorine. All good. After working, the next day water was cloudy and no chlorine according to test. Added 20 oz of liquid chlorine and this morning nothing registering on test. I added a dichlor tablet and chlorine came up a bit after a few hours. I couldn't add liquid chlorine because we were using pool.

Would granular unstabilized chlorine remain in the water longer?
Leslies has Power Powder Plus?

Also, checked PH after filling the pool with fresh water and it was very high. Perplexing--ok to drink but bad to swim in?
and Calcium Hardness was very low.

Finally, why are my numbers different than Leslie's Pools when they check my chemicals? I am using Taylor test kit.

Thank you!

 

[Endro32]

If you drained and refilled the pool completely, then you probably have zero stabilizer in the water. Especially with a UV filter, that is a recipe for chlorine destruction. I would recommend buying some stabilizer at the store and adding it to the water until you get your CYA level at least to around 30. That will help retain the chlorine. And don't try a different source of chlorine... it will only cause more headaches.

Finally, why are my numbers different than Leslie's Pools when they check my chemicals? I am using Taylor test kit.

Your test accurate, the store's is not. Pool store water tests are notoriously inaccurate for a variety of reasons, which is why the TFP method revolves around doing your own testing with a good kit.

 

[K9waves]

If you drained and refilled the pool completely, then you probably have zero stabilizer in the water. Especially with a UV filter, that is a recipe for chlorine destruction. I would recommend buying some stabilizer at the store and adding it to the water until you get your CYA level at least to around 30. That will help retain the chlorine. And don't try a different source of chlorine... it will only cause more headaches.


Your test accurate, the store's is not. Pool store water tests are notoriously inaccurate for a variety of reasons, which is why the TFP method revolves around doing your own testing with a good kit.

Thank you for your reply. Can I use the dichlor tablets and shock to get the Cyanuric Acid up. The whole reason I drained the pool is because the CA was so high. The water looks terrible and I'm so frustrated.

 

[Bperry]

Thank you for your reply. Can I use the dichlor tablets and shock to get the Cyanuric Acid up. The whole reason I drained the pool is because the CA was so high. The water looks terrible and I'm so frustrated.

You can use the dichlor. But remember all powdered chlorine has either CYA or calcium.

You can also safely swim even while adding liquid chlorine all the way up to SLAM level. Maybe just wait a few minutes for it to mix in.