Hey Skunky, from what I've recently learned, 5 gallon bubbling buckets should have the nute/water level approx. 1" from the bottom of the net pots. How will lava rock provide the roots with enough ntes and water? 100% lava rock and no verm. or perlite? Last night I bought a bag of lava rocks and I plan to use them-per your directions. For 6" net pots, I would guess using the small rocks out of the bag, verses larger sized. I still have Verm. and perlite, fresh bags just waitin'...... If you could point out a few details, that would be cool.....