Vostok, in micropropgations studies on cannabis (there's not very many, but enough for some good knowledge) they use a nutrient mix called MS media (stands for murashige and skooge medium; named after the scientist who discovered it) anyhow, ALL of the studies have a consensus that 1/2 strength MS media (1/2 strength mineral nutrients) outperforms NONE OR full strength.
These studies also conclude that IBA is better than IAA OR NAA for rooting cuttings, so pay attention to the hormones in you rooting gels/powers. IBA is the one you want.
If you want to get technical, these studies also point out that anywhere from 0.5 to 2.5 micromolar [[[that's a measure of molecules in solution used by chemists; there's a way to convert to ppm, but I'm already writing too much]]] is the best concentrations. IN these studies they test several strengths of these hormones to come to these conclusions.