Strain3ranswered grow question 4 years ago Hello again Yukon_Pico :)
By saying premixed solution, do you mean that they are mixed in a reservoir or a tank? If so, then I assume it is being oxygenated by an air pump, otherwise it will start to go bad in a couple of days or so. Even if you are pumping air inside the solution, I wouldn't suggest keeping it mixed for more than 1 week.
As for your question, hydroponic nutrients typically have different mineral ratios than the soil nutrients, but that doesn't mean you can't use them on soil :) Usually half the dosage is good for soil, so you would have to dilute it a little bit before using.