New Pool For The Quack Pack

My "quack pack" is 3 Indian Runner Ducks, 5 Rouens and 3 African Geese. Their yard is shaped like an L (actually an upside down L)...They have 2 pools 4' diameter that fill up w/ fecal matter, etc in less than 24 hours. Today I bought them a new 5' pool. It's amazing how much 1' diameter difference makes in size. Anyway, I'm fidna redneck engineer a drain so I don't have to flip this big sucker whenever I need to change out the water. I have what I think is a clever idea and will take pictures to keep anyone reading this up to date. Maybe I'll get some input as to how I could have done better and/or easier. I'mall about easy!