Nice work, i am currently looking as the last failure of mine. I am trying to get everything out of my 5x2x2 planted. I used 4 in pvc, about 24 inch in height, filled with bio balls, heater out the top and co2 plumbed in to the bottom of the reactor. Thought it was a good idea but turns out that the polyurethane based sealant/ adhesive does not stick to plastic. Found that out when i hard a medium sized water leak. Do you have any experience in glueing plastics or do you rely on a gasket of some sort.