Distance of the light usually depends on heat, HPS get hot!!! Keep an eye on temps and put your hand over the top of plant if your hand gets hot move light farther away until your hand doesnt get hot. You dont need a watering schedule sometimes your plant will use more water than others. I water when my pots get light, using light pots to start with helps this technique. Moisture meters is another way to go and are cheap and sold almost everywhere. Also Ph is very important keep the Ph at 6.5 - 6.8 hope this helps you out.