I'm a big supporter of the Botanicare Pure Blend Pro. It's a kind of 50/50 synthetic, organic all in one nutrient. You really shouldn't need to add anything else.. but as long as you can identify over feeding and toxicities. You can feed that plant whatever you want.

Some other good suggestions would be stuff from CamelGrowJoe and The Bio-Canna line.

Be sure to check out the "Sweet" by Botanicare as well. An all natural carbohydrate synthesizer that comes in different flavors like "Berries" and "Citrus".

Hope this helps & happy growing,
Bob.