I'll give a try at it, but if I'm wrong, someone feel free to correct.

The desired dilution is 2.5 oz per 100 gallons, or 2.5 oz per 400 quarts.

You did 2 oz per 1 gallon (or 2 oz per 4 quarts)

The strength in the tsp should be the same as the strength in the 1 gallon mix, which is about 80x the amount desired.

Next you did add that to 1 quart, which gave .01 oz per 1 gallon, or 1 oz per 100 gallons. So you are under.

Thank You So Much!

I get lost in all the conversions. I needed a verification.

I didn't want to confuse the issue but the maximum ratio is 2.5 oz per 100 gallons of water.

The lower the ratio the better because phosphoric acid adds phosphorus as a fertilizer.

So I am safe at that level.