Not sure how others do hempy grows (mine's in perlite), but I have a drain spout about 2" above the bottom of a 7-gallon container. This means there's always a little bit of nutrified water available if the roots reach down that far (and I'm not 100% positive they do). Typically, she'll take about a gallon of feed every 4 days (without leaking excess). Her next feed is scheduled for Tues 4 Jan, so I have a couple more days to decide how much to give her (if any).