Hello Rastsgal I really don't know much/anything about the different nutrients I've seen all the different ones in the growshop before but never used them.
All I use is Phostrogen plant food, I just put a pinch or two of that in the water every now and again

I can remember reading in a book once about all the different things that a plant needed and I read on the ingredents list on the box that Phostogen had them all in it .........................mind you if they are in the right amounts I have no idea , but I've always used it.
B&Q wil have it in, most shops that sell gardening stuff sell it

love mand xxx