"Weeds" TV SHOW is awesome. What hydro are they using in Season 2?

I'm at Season 2 and the show is awesome.

But I can't understand what hydro system they're using in their first grow house.

They just have containers filled with hydroton/pebbles and no drainage under them. Or is this just a flaw of the show?

I love that show too!!!! I just finished up season 4 i think... i dont have show time i just like to rent them by the season at blockbuster and go on a marathon...lol.. as far as the system, i dont remeber but if you look at the credits Advance Nutrients is there consultant so i a sure it something that exist.. maybe it was like a bubbleponic system, they alway have the lastest..... This last show i seen on season 4 they had a vaporizer thingie that had the lighter in it already and you just put the weed in and press the button it was like portable vaporizor it was as big as a lighter...