First off, welcome to rollitup. I think you'll find most folks here really friendly and eager to help, just remember everyone has their own way of growing and there are many "right" ways to do things, also its the internet and theres no stopping idiots from sharing their advice, just take everything you hear with a grain of salt and you'll be hunky dory.
I'm also new to hydro just establishing and ebb&flow system, hopefully you can avoid some of my mistakes.
Heres my first 2x4 table
I went with netpots not knowing any better, apparently its a no-no in flood and drain and you're much better suited to use plain black plastic pots. Roots just hangin out in the light are gonna curl up and die, or worse, start growing crazy pathogens on them.
Having said that, I was given a couple options as to how to deal with my situation.
#1-fill in all the gaps with hydroton, kinda unappealing in that it is apparently a bitch to clean after the fact, and it weighs a ton
#2-cover the pots with poly. Now thats my kinda solution, quick, easy and something you can do with a joint in your mouth.
I did a pretty sloppy joint-in-my-mouth sort of job here, and have since cleaned it up a bit, but you get the jist of it.
One thing i've learned pretty quick in hydro is that the light is friend of the plant, and enemy of the water.
feel free to check out my grow 'journal'
https://www.rollitup.org/grow-room-design-setup/106178-zeus-1400w-canadian-basement.html there might be something in there of use to you.
andyhow good luick and happy growing.