im not sure what the stockman pipe is....LOL :huh: , but I know that no siphoning is required with this setup, once the water level reaches the open end of the pipe, it flows over and down to the sump on its own. I hate the hang on overflow box that I have on my undrilled reef tank, you have to get a mouthfull of saltwater to get the siphon going...nasty! Anyway, please elaborate on the stockman pipe..