As the saying goes: necessity is the mother of all inventions. Had a water leak in my system and needed to test and while I was in my garage I saw my small fountain pump that I hadn't replaced yet. cut the top of package and used that as water tub, It came with several size fittings, then used some fairly large o.d hose that I got from a RC cooling kit that I had. worked it in the pump fitting, added a few drops of super glue and pushed in a bit more. connected hose to transom fitting, dropped pump in package tub and plugged in ac cord. To my amazement it looked to have the same output flow while running. Found my leak. This would be a great portable tester as long as you have access to a AC power source. Tetra® 75 GPH Fountain Pump, part #0204500 I got this at menards. Just a FYI that could maybe help boat racers. Hope this helps someone!