Ze I hate to see no replies to a question, well I've replied but for what good it's ......................

I don't know what MG is, but I understand you're asking about nutrients. I just grow really basic and the only nutrients my plants get are a home made compost, I'm really against the shop stuff, why should I pay out for what I can make myself ....Which I know is full of good materials.
I also put a pinch of Phostrogen plant food in the water for them now and again. They usually grow healthy and I get decent crops from them

Sorry Ze, ................alot of what is said on here goes right over my head but I'm reading and learning all the time

love mand xxx