You put a layer of hydroton on the bottom of the net pot, next you put the rockwool cube(or other grow medium) on top of this layer of hydroton. The plant will grow thru the rockwool cube, thru the hydroton, and thru the net pot and into your water resevoir.
All you need are 3" net pots. If you start your plants in RockWool, be sure to cover the RockWool completely when putting them into the net pots. That keeps algea growth down. Oh, and if you decide to use 3" net pots, be sure to drill 2-7/8' holes and not 3" holes. If you drill 3" holes, the net pots will just fall through them.
i have a 3x3x6 area but only have a 150hps for now, this is my first hydro attempt so im reading up a bunch. i ordered 3in pots and they seem kinda small, will they work?
what do you mean by drilling holes? I never drilled any holes in my net pots or rockwool. I am using 3 inch net pots and they seem to be working just fine for my hydro grow. Come check it out bud
I just want to add that while you can grow with less roots in hydroponics, the root volume does play a role in the potential yield.
If you find you can fill all the open space in a 3" net pot you'll want to get something bigger, but unless you're packing them full of Voodoo Juice or something you're not likely to need that.