Any other fert out there is better than MG. I mean, MG will work, but will not give the plant all the supplements it really needs to produce worthy smoke.

Just keep the numbers close to what the plant needs during the stage it's in.

For example, for vegging, I use Fish Emulsion (organic) that is 5-1-1, so just find numbers for the vegg stage that have a high N number (N-P-K)

For flowering, choose something like 10-15-10, or 15-30-15, something along those lines.

Just avoid MG, it does more damage than good.