Unstabilized tablets

[waterbear]

cal hypo tabs (unstabilized) are fast dissolving compared to trichlor and are meant for use in the skimmer, not a floater, since they need a vented dispenser. They really do not offer much advantage over bleach or liquid chlorine except that they are solid and not liquid and have several drawbacks. They are more expensive, they will cause calcium hardness to increase and are dangerous to store and can ignite and start a fire when mixed with other chemicals.

[chem geek]

Cal-Hypo is also a chemical that doesn't bind together well even under pressure when making pucks (unlike Trichlor) which means that they have to add binders/fillers to the Cal-Hypo to help it to stick together to make a tablet. So as these tablets dissolve, they often leave an insoluble residue, especially as the tablets gets smaller and tend to fall apart more quickly.

[CarlD]

There are some that get around Chem Geek's problem by actually encapsulating the Cal-Hypo in plastic, which, when empty, you must discard. I believe PoolLife may still make them but HTH only makes the tablets, which are horrible. They are supposed to last 5-7 days but I found, in my skimmer, they dissolved in less than 12 hours, and into a skimmer clogging wet cement. I will NEVER use them again.