promix is a good medium, you just have to get used to using it. i use cheaper peat, add some perlite, and amend it myself with a little garden lime and a little kelp and alfalfa meal. works great.
don't get a moisture meter....learn how to tell when your plants need something. feel the pot when it's dry, and note the weight of it. feel the pot the next time you think it may need watered, if it's still too heavy, wait. if you see new growth coming in very lightly colored and growth seems to slow down even slightly, they need fed....