trauh,

If you choose to use cal-hypo (calcium hypochlorite(, that's pretty much a pool store product. However, don't buy it in the 1lb bags........at least a 25 lb tub to get you thru the Summer....much cheaper.

You'll dose probably around 8-12 ounces by weight to raise your Cl by 2ppm.

The cost will work out fairly close to bleach and you will gain the advantage of not having to purchase any additional calcium