CYA re-visited

[tacoma5050]

So I am at my local pool store to pick up calcium increaser. I try to support my local store when I can, so I ask them: "do you have any un-stabilized chlorine". And they ask my "why do you want that". I tell them because my CYA is already high at over 80ppm and thus I don't want my CYA to increase anymore by using 3" tabs, So I will use unstabilzed chlorine until my CYA drops below 50.

They looked at me like I was crazy. They said I will have to add unstablized chlorine evey day to keep it at a necessary level since unstabilized cholrine does not last and that my CYA can be as high as 200 before I have to worry anyways.

It was my understanding from previous discussions that if I have enough cya in my pool that it will stabilize any un-stablized chlorine that I added?

So, will I have to add jug bleach every day or not?

[Guest]

They're nuts! 200?!

Let me tell ya, dumping chlorine every other night is not bad at all and I don't have to worry about high CYA. At all! And neither will you if BBB is the way you wanna go. 5 minutes a day is all it takes.

Don't buy his line. Go to Wally World and buy Ultra Unsented bleach and you'll be set.

[chem geek]

Your pool store is only half right. You can have higher levels of CYA and relatively low chlorine levels and not get algae, but to do so you need to use a supplemental algaecide such as a weekly dose of PolyQuat 60 or a phosphate remover or copper metal ions (but be careful of staining at higher pH). As was pointed out, if you manage your CYA level and keep the Free Chorine (FC) at least at 7.5% of the CYA level, then you can keep away algae with chlorine alone (this rule works up to a phosphate level of around 3000-4000 ppb which is quite high). The choice is up to you.

Richard