I do feed, feed, water...
Depending on your tap ppm, or if you're using and RO, I recommend feeding them 500-600 ppms of nutrient. (If tap is 100 ppm, final ppm would be 600-700) just add the regiment from the chart to some water, and add water until you've reached the right ppm. Then adjust the pH. If you're using R0, you might want to add a bit more micronutrients.