[decodeddiesel]

well a "Y" connector has no way to distribute the flow evenly. In other words the water is not going to go evenly through both sides, rather the water will flow more on the side that has less "resistance" or creates less back pressure. Also the ID of even a 1/2" Y is LESS than 1/4" so it's going to constrict flow greatly. If you were to build your own "Y" connector with 2 ball valves on each of the outs then have a flow meter right after the split you could tweak each of the valves untill you had matching flow. This is hard to describe here, but basically I'm thinking a brass fitting comming off the OUTPUT of the pump with a valve on each side. It would probably be much easier to try this with 2 smaller pumps then join them at the showerhead in the bong than to try this, but I think with 2 valves acting as flow limiters you could do it.