use General Hydroponics "Floraliscious". It's compatible with the 3-part system and they publish how much to use and when along with the 3-part. I use Hygrozyme too, it's a root treatment ensuring the best regeneration of root matter, and utilization of old root matter. Be careful though, don't fix anything that's not broken. The introduction of organics and root stimulants to your chemical nutrient resevoir can turn things on a dime if you don't watch it (pH levels for instance), but they have magic shit in to make the plants grow to their potential.

General Hyfroponics has tested and true nutrient regimes including their own supplements and foliar spray. Although GH is not crop specific to marijuana like Canna Nutrients or other big dogs, I would venture to say that it has what it takes to do the job. If you read a lot on this message board, you will get some great advice.
ALso, there are 4 or 5 "recipes" you can use just using your 3-part system that are different then the bottle suggests. These recipes are tried and true for marijuanja such as the "Lucas Formula". Do a search on the message board for "Lucas formula" and you will probably get the page with 5 links to 5 different ways to use the 3-part for growing your own.

If you can't find it, then just ask Zandor.

Peace out homey