I put my walls at four deep which extended the time for the print. I have used both PTEG and PLA for printing this, PLA will do, but PTEG is better. Its not that the quality of the finish is much better, but the PTEG is as tough as PLA without being as brittle. I also used an M3 threading bit, to thread the holes between the top and the bottom and then also some contact adhesive to make sure the bottom was well afixed to the top, as I plan to leave this in place during winter (although I will flush the hose).
I used support material between the plate and the object, basically its a small amount of support for the hose couplers when printed vertically upright.
I use Cura, and it said the model may not be water tight, but after printing and using it, i found no problems.