Well, HD was into a heavy nitrogen nute for veg, which is why the 11-1-1 bat guano was what he suggested for me. If you have great dirt, then I don't see you using any nutes before flowering at 18 days. I'd start with SuperThrive on Day 1, though.

Here are two quick links to cactus juice that I found:

http://www.starnursery.com/show_deta...=2&product=542

http://homeharvest.com/houseplantfood.htm