Last winter's grow I used three cups of suger to a gallon,, I was using a six gallon kerosene clear plastic can(new) but with four gallons of water in and 12 cups of suger, my yeast I used was turbo yeast for making moon shine,, 3 generous teaspoons,, after I mixed I took the cap and ran two lines through it (1/4) clear fuel lines about six feet in length,, the other ends of the lines I put through the lid of a mason jar,, so there was two lines in and two out,, which I placed in another open jar with water in it so when it starts cookin it boubles the water ,, I hung the jar with the water over the plants,, the reason for this is to act as kind of like a valve,, this way if it backs up it will suck the water back into the first jar tellin you to and more sugar,, I had this in my 2'x8'x6' closet and it worked great,, but I can't tell you the ppm,, after it cooked off I made moonshine form it,,
I'm not sure that this helps much seein I can't give you a ppm read but the plants thrived and I had no issues