65% Cal Hypo

[chem geek]

Yes, it would be economical at that price. Just keep an eye on your calcium levels if you end up using this as your only source of chlorine. 1 pound of 65% Cal-Hypo increases the Calcium Hardness (CH) by 5.5 ppm in a 10,000 gallon pool (the ppm rise would be less in a larger pool, etc.) and depending on the specific brand you use it could increase calcium even more (it depends on what the 35% inert ingredients are -- sometimes some of them are calcium salts such as calcium chloride and calcium hydroxide).

Richard