So I just finished my new brew stand build and am having an issue with the pump. I built a two tier system. HLT is on a burner at the bottom, MT above the HLT, and then BK off to the side on its own tier. My HLT is a 7.75 gallon half keg. When I welded the bung for my ball valve, I accidentally put it just below half way up the keg. I bent a piece is SS tubing in to a dip tube to draw from the bottom of the HLT. From there it goes through a ball valve and some more SS tubing to my pump which is located below the bottom of the HLT. The pump is a Chugger SS inline. The issue I am having is that the pump will only drain the HLT to about an inch below where I welded the .5" NPT coupling as a bung. Why is this? Since I have a dip tube, shouldn't that draw a natural siphon to my pump which is lower than the lowest point of the dip tube? From there the pump should maintain that siphon and then pressure pump up to my MT? Does the Chugger pump I bought not actually draw liquid from the input side? If I raised the HLT would that give more of a siphon effect? Or am I completely over thinking this?