I mix my own liquid ferts from powdered forms, I make stock solutions where I know how many ml per gallon are needed for a certain increase in ppm. I find it easy to dose them and makes filling the liquid dosers easy and precise. It also helps when keeping small tanks such as 2.5 gallons where a watered down solution is easier to dose rather than counting drops or very small amounts of powders. But both work and I don't think it makes much difference to plants and such. Traces may possibly have a longer shelf life if kept in powder form, I wouldn't know as I usually only prepare 250ml at any one time.
Giancarlo Podio
Giancarlo Podio
