Now with a more accurate pool volume, and knowing how to play with the calculator, you should be able to get the water parameters straightened out.
Do figure out your total borax additions, and use the Effects of Adding Chemicals section to figure out your borates ppm and plug that in to the calculator; it does affect pH-related calculations. That second round (3lb) was worth 10ppm by itself, which is why I was guessing 15 but it might be higher.
If something else unexpected happens, don't hesitate to post here and there will be somebody to help out or reassure you. (I'll keep an eye out for this thread but I'm not on every day.)
--paulr
P.S. Dave, it's not like I don't have my own list of boners to live down...