Please remember to keep all specs exactly the same as heaths and use a squat and heavy producer . Paradise Seeds Wappa is a very good candidate. The specs must be the same. Including the free air space that surrounds the outside of the 4" tubing spiral. Here is why: when Heath lays the 20" round non oscillating circulation fan in a horizontal (blowing upward) position it creates a lot of air pressure flowing upward within the vertical piping spiral . The pressure differential that is created by blowing the hot air mass from within the spiral ( blowing from bottom to top of course ) not only blows air upward toward the undersides of the leaves ( exactly where the stomata needs it) it pulls air horizontally in between the 4" pipes from outside of the inner diameter of the spiral toward the center. This simply placed horizontally oriented fan blows air upward and pulls air inward from in between all the 4" pipes. The most perfect airflow possible. It cannot get any better for this set-up unless you put an extraction fan in the mix which pulls the air from the ceiling centrally located above the bulb ( but that theory is untested). I researched every single available vertical grow journal that attempted to have the same success Heath did with his Flooded Tube Vertical. Here is what I found. All have fell very short of his glory because none have had 100% respect for his science. Nobody copied every aspect of that grow exactly. Nobody! Here is a list of the burdens to get the same success or better. 1.) The inner diameter must be the same as his 2.) you must use the dams because it creates surface turbulence throughout the air/water interface which in turn is the reason why he gets so much oxygen to the root zone ( the outflow into the reservoir has less to do with getting the oxygen there than this trick he uses, all without airstones) and brings the root zone in close contact with the water surface 3.) Please refrain from using more than 1 -600 watt hps and do not make a 1000 watt version unless you know how to proportion all the spacings and other dimensions accordingly and you are willing to add an exhaust fan to the mix ( although I would just try to emulate his 600w first before trying to one up him). 4.) remember that you never want the 600watt lamp to be further than 2 feet away from the plants 5.) you must use the same or better reflective pipe insulation . 6.) 20" articulating round fan absolutely necessary. 7.) Inner Diameter of the vertical grow space must be exactly the same.Remember that his 4" tube vertical style yielded better much better results once he started using the dam and made the inner diameter of the 4" pipe such that the fan blowing air from the bottom to top would also pull a lot of air in horizontally between the pipes because of the hot air pressure differential from the inner and outer diameter of the air space on either side of the 4" pipes. It's like he has a multitude of fans blowing into the center between the 4" pipes. But you must keep all dimensions the same as he did. You must have full respect for science because the chain is only as strong as the weakest link and if you're attempting to emulate him please bear in
mind that people have a 0% success ratio when they do this (ALL WHO ATTEMPTED TO COPY HEATHS FLOODED TUBE VERTICAL FAILED MISERABLY, I SPENT MONTHS LOOKING INTO IT sorry for yelling ). The common denominator I found with all the failed emulators was their disrespect to do everything the same way he did. It's like the old saying goes... WHEN ALL ELSE FAILS READ THE INSTRUCTIONS. Those instructions are contained in the thread titled HEATHS FLOODED TUBE VERTICAL. He uses the dam, so you have no choice but to do the same.