4 Way Valves 

Minor note, when connecting this I made the mistake of putting the high pressure side, on the water supply. Even though the water supply is high pressure, that's not the place you want to put the high pressure In-and-Out fittings. The water waste discharge is also high pressure, the problem with closing the supply water , is when the valve closes, it starts to cut the water pressure that would otherwise hold the valve itself closed. so it would shutter, Making a buzzing noise as the valves rapidly opens and closes, because the water pressure that is used to close the valve is removed, when the water supply is closed.The waste water discharge tube is also high pressure, however when that side is closed, it doesn't cut off the all pressure supply, which allows the product water, or low pressure side to maintain enough pressure, to hold the valve closed. Closing the waste water, in addition to the product water slide, will stop all water flowing, just like closing the water supply manually would. The benefit would be that when the product water is open everything starts flowing, meaning you would not have to shut the water supply off manually when you finish filling your reservoir. You might want to make a note of that in the video description, so someone doesn't make the mistake I did.

Mate, lamens terms would have made this useful.