So I was thinking the other day. Our first trailer had one drain for gray and black water. It seemed that thing took for ever to completely drain both tanks thoroughly including using the sani-flush.. When we bought the new trailer I was a little disappointed that it had separate drains for each. But after two trips I'm pleasantly surprised we can drain both tanks at the separate valves and use the black flush quicker than before. Granted the new trailer tanks are 30 gal and the old were 40, but don't think that is making a big difference. When my wife mentioned it I told it must be because the drains are a straight shot right out of the tanks with no bends to navigate. I do have a Y-connector set up for when we camp with sewer hook ups, hopefully get to use those when Pismo Coast Village opens back up. I know exciting post, but I'm bored.