I make 11 gal worth of the Jacks321 solutions in advance. I dissolve 39.6 g of Part A, 26.4 g of Part B, and 12.1 g of Epson Salts separately in 2 liter soda bottles.
Part A is darker, so that one is obvious. I put the Epson Salt in the Barqs bottle, because it’s different from the Jacks. 2 liters is roughly 67 fluid oz. 6 oz from each bottle will go into each gal of water/nutes.
I fill the gal jug up with .75 gal of water then mix in 6 oz from each bottle. The Solo cup is marked to measure a 1 gal dose (and 1.5 and 2 gal dose) of 6/9/12 oz. On feeding days I just shake up the bottles and measure out how much I need from each bottle, mix it in with the right amount of water, and start pouring. I keep the bottles in the dark, under a counter.
When I also use Flower Fuel, I dissolve the FF in the .75 gal of water first, then just pour in 6 oz from each of the three bottles. I give it a little shake back and forth and use it right then.
It doesn’t matter if I’m making 1 gal or 5 gal… I’m usually finished mixing and watering in 5 to 10 min.
I did the same thing last summer, but with higher concentrations and in gal milk jugs. My outdoor plants were drinking 5 gal of water every other day. I tried different techniques. This was simple and fast. And I only have to measure out the nutes every other week or so.