I was a MG fan..., but between moisture control & pre-nuted they are just not worth MY risk...1st no plant needs nutes when they're seedlings...They are fine by themselves for about 3-4 wks. The best is "you" control water & feed.....like paint man.....easy to add more if needed, but almost impossible to remove if too much..
Just water evenly making sure not to get hot spots where theres not enough water...you will get nute burn if the nute is not completely dissolved, and hot spots leave undissolved nutes creating salts....You can tell about watering by weight..(dry & wet) or my favorite...when soil starts to pull away from the plant pot..I don't buy all the water, sun zodiac......etc meters...I would suggest a PH meter $10. wal-mart, but besides that I don't use other things....They are alive and once you get used to seeing the cycles, you'll be able to tell...
Good Luck