I was actually going to ask this same question yesterday, so it's a good thing you asked it today! I'm curious as to what other people output (and I know it's highly individualized, based on how much you drink, etc). i'm in the middle of doing my 2nd 24 hr test, and I don't feel like I've put in nearly enough. The first one I filled 1100 mg, which wasn't even one full container. I don't think I'm going to fill this container this go around either.
The Blood tests look at a variety of things - your liver functions, kidney functions, creatine clearance, etc. If those numbers are elevated, it usually means there's a problem -- either Pre-E wise, or other health issues wise.
Good luck, and make sure to keep us posted on the outcome of this one!