Here's a link to bleach calc, save it to your desktop and you can use it whenever you need to. http://richardfalk.home.comcast.net/...achCalc262.exe

As far as the alkalinity goes, as long as your pH is stable, *I* wouldn't adjust it. If it ain't broke, don't fix it! If you want to add baking soda to raise it, add just a cup or two at a time, circulate, and test again before you add more. I don't know anything about the phosphate question, but it seems to be controversial. Perhaps one of the experts here will address that for you.

Try to test your cl level 2-3 times a day and add enough cl to bring it back up to shock level each time you test. How does your water look, and what are your test results this morning?