i agree with jack; it just depends on the plant. If you watch your plant closely you can tell when it is getting too much food (darker green foliage); contrariwise, you can see when it's hungry if it gets a lighter green.

I think if you begin introducing nutrients very slowly (i.e. start at 150 ppm and work your way up) you can be alright, but not until the plant has 3-4 nodes. It really just depends on the plant, so get to know yours.