Confused on Bleach, Calcium Hypochlorite, and Sodium Dichloroisocyanurate

[aylad]

Calcium hypochlorite is a source of chlorine that can be used if your calcium levels are not already too high. High levels of calcium in a pool, combined with high pH and high TA, can precipitate the calcium out of solution, causing milky water. But..it's fine to use if you don't have high-calcium fill water, as long as you switch to something else when your calcium levels start getting too high.

Sodium dichlor is another source of chlorine that can be used until your stabilizer levels get to where you want them. Stabilizer (CYA) is like sunscreen for your chlorine--you need some to keep the sun from eating up all the chlorine, but the higher your CYA levels get, the higher your chlorine levels need to be to keep algae away. (There's a "best guess chlorine chart" linked in my sig that explains that concept further, but if you can't follow the link, then log out and go to the main forum page, into the section called "using chlorine and chlorinating chemicals". The chart is the second sticky in that section. If you use dichlor, it tends to drive your pH downward, so you'll need to keep an eye on it. However, in a pool that has high pH, high alk, and needs stabilizer, it is actually a better chem to use than any of the others.

Another alternative to using bleach might be using "liquid chlorine", if your state sells it (Louisiana doesn't). It is the same as bleach, but in double strength, and is often sold in carboys that can be refilled. For those who have it available, it often is the most efficient and cheapest source of chlorine. The downside is that it breaks down quickly in heat, so you have to be careful to make sure that it is actually the concentration (usually 12-15%) that the store says it is.

Hope this helps!

[PoolDoc]

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