I agree with Kennny! My biggest mistake with coco was not giving them enough water. I personally water every 2-3 days and give them enough water where there is 20% runoff (feeding every watering). I keep my pH level at 5.8 which seems to be the sweet spot. With chemical nutes (I use Fox Farm), be sure to not follow the schedule exactly. I recommend starting at 1/4 the recommended levels and see how your plants react to that, then slowly work your way up. Mid flower I burnt my plants at around 1400ppm which is what they suggest.
What type of pots do you plan on using? Reverse osmosis water or tap water (if tap, what's the ppm)?