Here is the link to BleachCalc
Get BleachCalc 2.6.2 here:http://home.earthlink.net/~mwsmith70/data/BleachCalc262.exe

The other thing you really need is a GOOD test kit such as the Taylor K-2006. An even better 'bang for your buck' (and the one that many of the forum members use) is the PS234 sold on the forum's sister website www.poolsolutions.com