Why no pucks without stabalizer

[hancop]

This seems so simple to me, but maybe I am missing something. Why do no manufacturers make chlorine pucks without CYA. If somebody did, my guess would be that most people here would probably buy them intead of using bleach. There must be some reason you can't buy them without the added stabalizer ?

Does anyone know why ?

Thanks

[CanuckPool]

I sense a tremor in the force... a chem geek posting is about to happen.

[chem geek]

The force be with you!

If it were easy to make a chlorine source that was slowly dissolving without CYA, then it would have been done already. It's not easy. There ARE Cal-Hypo pucks you can buy and these are essentially Cal-Hypo powder that has been compressed under high pressure into pucks. Technically, TriChlor tabs are made in a similar fashion.

Of course, with TriChlor pucks for every 1 ppm FC you add you get 0.6 ppm CYA. With Cal-Hypo pucks, for every 1 ppm FC you add you get 0.7 ppm CH. So one way or the other you are going to build up something you may not want. All things considered, the CH level isn't as critical so adding 50-100 ppm CH over a season isn't such a bad thing and is probably a reasonable option for some pools, especially if they drain/refill or dilute with winter rains to get ready for the next season. As has been mentioned on this forum elsewhere, some pools can use TriChlor pucks because the pools are smaller and their filters are backwashed regularly, so they can keep CYA under 50 ppm.

You CAN buy lithium hypochlorite which is a quick-dissolving powder and I suppose that someone could try and compress it to make a puck, or add some binders to it to hold it together (something else to add to the pool -- yech!), but this source of chlorine is VERY expensive. I have no idea if lithium causes any problems in pools -- it is in the same "class" as sodium and potassium, but does exhibit some unusual behavior in forming some compounds. It's probably OK. Too bad it's so expensive.

Richard

[GraceByDesign]

I think this is the first of Richard's many posts that I can actually understand!! Maybe I'm getting smarter!! ;)

(I wish!) :rolleyes:

[CanuckPool]

I thought that myself too, maybe he is having an off day.

[ehorn]

To add to that as well, in laymens terms, that CYA does not come out of the water unless by splash out, bathers, etc. It is similar to salt in that regard in that it persists in the water. So you would not want to be constantly adding CYA if you are at the level you want already.

From what I have learned you only really need to check CYA once a season or maybe every 3 - 6 months if you have heavy bather load or splash out.

Eric

Opps, I just realized after I posted this that the topic was NO CYA in pucks. Guess it's been a busy week. That is odd that they add CYA to the pucks knowing you can't really remove it once it's added.