need help with understanding dwc

i am changing from ebb n flow to dwc, i am going to be using a tub 2ft by 2 1/2ft im going to cute 6 holes on top for 6 plants im using 2in rockwool cubes and clay pellets for medium in net pots i also have heavyduty air stones, now what i dont know is how far should the net pots be from the water and i dont know if i need to have a pump i have seen the dwc buckets but i want to use a tub, im not sure if i have to feed from the top or what, please any help with this would help ty

in this system would the roots just grow into the water and the air bubbles will stop it from drowning and i do not feed it from the top...is this right....im just tryen to figure out how it works

There is an entire section on dwc every question u have has an answer on there

Keep the bottom of the net pots between 1/2" and 1" above the water - do not put the net pots directly in the water. When you transfer the rooted plants into the net pots put the base of the stalk at the bottom of the net pot (dont bother putting the roots into the holes, they will find their own way believe me) and fill with hydroton or whatever. Place in the DWC unit and get a very strong air pump and several air stones. I would recommend 1 air stone for every plant and place the air stone directly under each net pot. Not sure how you could secure them there but there is water droplets that fly up when the air stone releases air under your net pot. You want those water droplets to hit the bottom of the net pots. The water should look like it is bubbling violently. [video=youtube;CTzyWJxIb2E]http://www.youtube.com/watch?v=CTzyWJxIb2E&feature=youtu.be[/video]

ty very much for the help and the video im going to make a video tomorrow on what i make

[video=youtube;BV2EdMiDRu8]https://www.youtube.com/watch?v=BV2EdMiDRu8[/video]
heres what i made what do u think about it