What is the source of the nitrogen. That is normally the biggest issue with non hydro fertilizers. and the lack of micro nutrients. and the imbalance of a 20-20-20, hydro fertilizers are more along 5-11-26.
Since you're new to hydro, you should probably just buy a small qty of General hydroponics flora series nutrients. then, if you decide to do more with it, you can look into more economical options.

Trevor117
I'm not sure if the nutrients your referring to are hydroponic nutrients or not. JR Peters makes both hydroponic and soil nutrients. But in either case I suggest contacting them directly. They will be able to tell you exactly how to mix them. In the case of the Herb formula I bought from them, it comes out to about 12 ounces makes 100 gallons of full strength nutrient solution.

For smaller amounts, just weigh out the 12 ounces, then measure out how many teaspoons it makes. Then it's simple to just measure out only enough for the smaller (and weaker) amounts of nutrient solution you need.

Here's a link to their contact us page: JR PETERS, INC

Or dissolve 12 ounces in 3 cups (24 ounces) of water. then every ounce of water (two tablespoons) equals 1/2 ounce of fertilizer. so a TBSP is 1/4 oz and a tsp is 1/12 of an ounce.

check the ingrediants and percentages of the other nutrients. If they're the same, they will probably work the same.