@VoidObject, I personally like where you placed the hole for the air-line, putting it on the side gives less chance for detrimental light to leak in to the reservoir. Putting it in the top allows for the light to shine directly in any hole exposing the reservoir, which may cause root slime, which will kill small plants if left unchecked long enough(which usually isn't that long).
@CallMeDro, I am no scientist so this explanation may not be perfect, if you'Ve ever kept a fish tank you might know about something called "dissolved oxygen"?
With an air stone providing massive oxygen content to the roots, it allows them to keep strong and fresh. (Like fish in a fishtank).
Some folks will run their buckets on a full bucket of nutrients (within an inch to the bottom of the net pot )and let the plants suck it all up then "reset" the nutes and water.
This is done for convenience otherwise you will be screwing with the nutes and water on a daily basis. Cause once the plants take off it's frickin amazing how much they can take in..... (An entire 5 gallon bucket, in under 48 hours, is not uncommon, and is more normal than not.) So, really, it's still ebb and flow just on a larger scale per plant over a much longer period of time. Ebb and flow is dependent on a larger surface area and flow of the water to provide oxygen to the plant roots, whereas bubbling provides oxygen directly.
Also, if you use a strong enough air pump, at the very top of the water line , you will see little water bubbles jumping up, those little water bubbles believe it or not, will provide quite a lot of water to the hydroton, hydroton is really cool stuff for being able to hold both water and much valuable oxygen. Hydroton will actually act as a "self-wicking" material. So at first when the roots aren't so big they will feed off of the rocks, one the roots get big, you can run half buckets of water and nutes and allow the roots to sit right in the water, with the air stone.
What some folks will do, is bring the water level right up to the bottom of the net pot with the bottom of the net pot being 1/2 to 3/4's of an inch being underwater, throw in half of your pre-rinsed, pre-soaked hydroton(with half of a 1/2 gallon net pot), throw in some seeds(if you have enough to spare), lightly cover with rinsed hydroton(pre-soaking allows for their to be enough moisture in the rock to help germinate the seed), placing a wet doubled up paper towel with the light on, will help keep moisture in the germination zone, while also using the warmth of the lamp to help germinate the seed. Keep an eye on things for a couple days, make sure that the new little germinated plant is able to move the rock out of the way so it can sprout upwards. If not, you will have to help it.
The above method works, relatively ok, if you don't have rockwool cubes at your disposal.
Some folks have taken this even further and set up only a misting chamber, so that the roots are sprayed with solution every few times an hour.
I hope my 2cents helps, more importantly, I hope it's an accurate un-expert explanation. (I keep coming back every hour or so as I think of things that I feel are important and edit, which is why this has become quite lengthy), LOL!
