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 to lower my water level and see what happens. Can someone give me some incite to which way to flood is correct.

well i did some research and this is what I finally found. With an E/F system your flood level should be anywhere from 50 to 75 % of the container holding your medium. It depends on what medium your using because some mediums will float and if you bring the water level up to high it can float your medium and push it out of the pots. Two mediums I can think of this happening with are perlite and styrofoam.

I flood mine pretty high, probably like 90% at least, and my plants are thriving. I don't think how full you flood it matters except for the floating medium as you specified.

50% is the number you're looking for. Doesn't matter a whole lot though as long as the roots get wet occasionally.