I saw the "octagon" online. 6" bulk pvc is rather cheap, but the fittings are dumb ass expensive, on the order of 50 a piece. I'm currently constructing a pentagon, solvent welding the joints and stacking em up for ebb flo. The beauty about this vert system is you can really do any thing with it. Aero, RDWC etc. Ill post pics of my pentago, that picture is good for judgement. ive got 60 inch cool tubes with 600s. First row needs to be above the res, so the top of the tube will sit at 7 foot. line the inside with netting and youve got walls of green, and no popcorn.