Article about CYA and chlorine. TFP has it so right!

[pypeke]

This is an interesting, easy to read article which goes along with TFP's thinking on trichlor vs bleach, CYA, FC, etc.


I think the (commercial pool) article refers to FC as FAC, but maybe I am wrong. Someone can correct me, please.

TFP, you rock!

New Thinking: Chlorine/Cyanuric Acid in Balance

Crypto article. Stay out of pools for two weeks after a diarrhea episode. Any CYA in pools slows down the kill rate for Crypto or other bacteria. Survey Finds 1 in 4 Adults Would Swim With Diarrhea

 

[jeffchap]

"New Thinking..."

LOL!

 

[tim5055]

The first article is based on science developed here and a previous forum by many of the members, including Richard Faulk (named in the article, Chem Geek username here).

The second article is very misleading. While kill times for Crypto may be longer for a pool with CYA when you follow the "industry" advice of FC always being 1 - 3ppm, TFP levels of FC are based as a percentage of the CYA. As CYA is added or raised we recommend more FC which maintains the quick kill times. Do a search on Crypro and the user mane Chem Geek and you will find several discussions. But, with that being said, Crypto is resistant to chlorine even in the absence of CYA. Remember - not all persons are carriers of Crypto, so you need 2 things to happen to have an issue - First a person must be infected with Cryptosporidium parvum and second that person mush have a diarrhea episode in the pool.

 

[pypeke]

Awesome! It was very easy to read and understand.

My 2 year old grandson in a swim diaper had an "episode" last year. We scooped up most, but did not get all of it obviously. We SLAMed the pool that night.
(Memories of Caddyshack!)

I didn't know about the 2 week time frame! Geez, what a question to ask your pool guests!

 

[tomfrh]

Lowry (the source mentioned in the story) gets some things mixed up. Eg. he says FC of 7.5% of CYA is critical because it results in the required HOCl level of 0.05, which is what you need to prevent algae.

In actual fact you need 11-12% of CYA to get to 0.05 HOCl. This corresponds with TFPs “target” FC levels.