My mom had a little scale that I used. That's good news about the tank. I bought my LR cured and had been setup in a tank for quite awhile from a SW store by me and when I got a test kit two weeks later my tank was fully cycled and could have been even earlier, sure does help.
I'll let you know what I find out about the crystals though might take awhile to research them, busy with school this week no longer spring break

I think it was something to provide better living conditions for them, but they are certainly much more expensive than regular synthetic salt though for me it wouldn't be a big deal, gallon water change a week but for you it might get expensive, I don't know.