I have also looked into building one, but since I've never attempted hyro before I don't want to fuck of my first go by messing up a measurement or god knows what else. I am still considering building one but I would like to find a good step by step picture tutorial before I attempt it.
Well thanks for your post and yea I'm just going to keep reading and build one myself. 2*4 seems to be a more standard size then 3*3, should I go with those dimensions instead, I guess I would only be losing 1 square foot. 4 of those trays would fit nicely under 2 1000watt HPS.
Thanks for the reply and sorry if this post doesnt make much sense. I was just kind of thinking and typing at the same time.