chlor brite?

[waterbear]

They do make unstabilized chlorine granules...It's called calcium hypochlorite or cal hypo...it is slow dissoving in granular form and not slow enough in puck form so it's ususaly granular. It adds calcium every time you use it which might be good or bad depending on what your calcium, TA and pH are.

[graciec]

So check calcium numbers and maybe it might work in a vinyl pool in a pinch? What is a good brand(s) with the least additives and most available CH?

[waterbear]

Some people use cal hypo as their main sanitizer. It's biggest drawback is that you have to predissolve it and if any undissolved stuff hits the liner you have to brush until it dissolved or it can bleach the liner. Also if your TA is high it can cause cloudiness. Look for one that is about 65-68% active chlorine. Some of the ones out there are only abut 45% active chlorine so they put more 'junk' in your pool. Bleach and liquid poolstore chlorine (both are sodium hypochlorite) are ususally cheaper to use. There is another form of granular unstabilzied chlorine called lithium hypochlorate. It is the fastest dissolving, usually as it touches the water but it is only about 35% active chlorine and is the mo$t expen$ive chlorine you can buy! Other than pH it has very little impact on water chemisty just like sodium hypochlorite. Very few people use it because of the price. All of the above forms of chlorine can raise pH to one degree or another depending on which one you use so keep an eye on that and adjust with muriatic acid when necessary.