Thank you Ray. What has been confusing me is the label on the last number on the Mixing Calculator. It is the same as the label for the input to the calculator. I had suspected it had something to do with TDS; but really had no clue. Perhaps it would be helpful for you to relabel that field. Actually I do not understand the utility of that number if it is the total TDS for a month. I would think that the plants should only care about the current TDS after any watering/feeding.
Edit: I don't think I have been using the calculator you are talking about. From the perspective of a not terribly clever reader, may I suggest combining your calculators on a single page with a simple explanation of which one the unknowledgable reader should use for specific tasks. Like take powder/make concentrate/use x teaspoons per gallon. Probably a pretty common goal. Your discussions are quite informative if one understands. But they can confuse the uninitiated (like me).
So (to check my understanding) if I use 1 lb of powder in 3 quarts of water for a MSU powder with 17% N I will have a N of 4.25 in the resulting solution. This assumes that the pound of dry material has a volume of about a quart. If the total solution is less than a gallon I would guess filling to the gallon mark would be appropriate.
If I enter 4.25 into your Mixing Calculator (4/month & one flush), I get 3.14 teaspoons of concentrate to 1 gal of water. How does Pi figure into all of this
EDIT: I went to the calculator I think I should have been using. The Fertilizer PPM Calculators and used the bottom one. That gives me 2.23 teaspoons of concentrate.