Im currently growing my mother plant which is a tutti frutti.

Its being grown in a 2 gallon tub(uk equevelant).
1 part rock wool and 3 parts B&Q multi purpose compost.
I use a dillute solution of MG every 3 days and my plant is growing tall and strong.

I did uses MG as a hydro fert on my first 2 plants, it did pritty well till i increased the fead and then it killed both plants.

Ive not really had a problem with MG except for when i was using hydros.