That link is mixing directions for 100 gallon amounts. How much are you wanting to mix? Going by the directions for the 8-15-36 fertilizer it comes out to a little less than 1 oz per 10 gallons (.8 to be exact). Or .08 per gallon.

Broken down from the directions in the link:

_____________________________(for 100 gallons)______(50 gallons)______(for 25 gallons)______(10 gallons)______(per gallon)
8-15-36.................................................(8 oz)...........................(4 oz).......................(2 oz)......................(.8 oz)....................(.08 oz)
Calcium Nitrate (CaNO3)......................(6 oz)............................(3 oz).....................(1.5 oz)....................(.6 oz)....................(.06 oz)
Magnesium Sulfate (MgSO4).................(4 oz)...........................(2 oz).........................(1 oz).......................(.4 oz)..................(.04 oz)

Because their directions are by dry weight, I cant give directions based on teaspoons and tablespoons measurements. But if it were me, I would weigh out the 8, 6 and 4 oz amounts for each ingredient for the 100 gallon volume (without mixing them). Then see how many tablespoons (tbsp) each makes, and write it down. From there just divide by 3 to get teaspoons (tsp), and then it's easy math to compare weights on their chart into easy to measure volumes from tsp or tbsp for the amount of gallons you want to mix.

As for how to mix them together. Measure out the volume of water you wish to use (10, 20, 30 gallons etc.) and put it in your reservoir. Measure the amount of 8-15-36 fertilizer you need, and mix it thoroughly with the water in the reservoir. Then measure out the amount of Calcium Nitrate you'll need, then put that in a measuring cup and thoroughly mix it with a cup or so of water (so it's completely dissolved). Then pour that into the reservoir and mix it with the nutrient solution. Then rinse out the measuring cup, and measure out and put the amount of Magnesium Sulfate you'll need in the measuring cup. And again completely dissolve it into a small amount of water, and then mix that thoroughly with the nutrient solution. In other words mix and add the fertilizer, Calcium Nitrate, and Magnesium Sulfate separately.

For best results measure and adjust the pH of the water in the reservoir both before adding anything, and after it's all mixed. But at least after it's all mixed. Generally with seedlings (after the first true leaves begin to grow) I'll use about 1/4 strength nutrient solution. Then when they get a couple inches tall, I'll up it to about 1/2 strength. Then when they get a little bigger I'll go to 3/4 or full strength.