50% is the number you're looking for. Doesn't matter a whole lot though as long as the roots get wet occasionally.
Opie Yutts Reviewed by Opie Yutts on . Ebb / flow water level help I have been flooding my pots which hold clay pebbles almost to the top maybe 1" under the stem of my plants. I just read a post that stated that you shouldn't flood no more that 1-1/2" from the bottom of the pots. My plants roots are hanging below the pots so they will get the water but I thought that the reason to flood the whole pot was to force air out and get fresh air as it recedes. I cut my water cycle down to 3 times a day and the plants still tend to droop after watering so I'm going Rating: 5