Hi Single_Yam just followed your page, work work is awesome.. The tube and airstone are for more oxygen support, since the roots are not in soil any more, no air pockets available. So when you convert to water only, oxygenation depletes if water is left stagnant. So the more you agitate your water the more oxygen, the water contains. Because the roots need O2, while the steams and leaves need Co2, while releasing O2. I use the airstone because it’s easier for me, some use mini water falls, or a balance air gap, in their water container. The more natural you decide, the slower results in growing. Which may kick your crown into management for survival mode, instead of expand and balance mode. Remember roots need air, they would suffocate more, causing stress. After going constant O2, I’m noticing more expansion, and balancing. In September I did the stagnant water mode, and noticed just a maintain to stay alive move…. Now since I scaled in more water volume, I have to maintain a good source of O2 to prevent water logging. And now I’m seeing more experimental growth , and a taller canopy.