Hey Bodi. As from my comment above I am no expert but I believe one thing you must be very careful with on these is proteoid roots. They are microzia looking extensions that are able to extract every ounce of nutrients out of the soil. It will grow them when the soil is lacking.
It has been written by Grant I believe that if your feeding of these is lacking and it has grown lots of proteoid roots and then you give them a normal dose of fertiliser it can be like over fertilising.
I believe the idea is to start with very weak solutions and slowly build up.
Ah here it is
I mentioned proteoid roots earlier and will now add a few points. In pot culture, if your Banksia is not potted and fertilised regularly, it will of course become pot bound and hungry and thirsty. It may at this point put out roots that enable it to scavenge even the smallest amount of food through these super-fine roots. If, however, at this stage you were to heavily fertilise the plant it may take up too much fertiliser and die.
From this article which also has some fertiliser recommendations.
http://asgap.org.au/APOL31/sep03-5.html
It will be intresting if Grant or Antonio have any different fertiliser programe than the one mentioned in the article as I believe it was written a while back.
It's too bad your in such a hurry cause the stories I could tell you, Bushels and baskets of stories, hole crates full of stories. But if you can spare a moment I will tell you one story.