I got a large pond liner, used a hole saw and cut a hole at one end of it that fit a shower or floor drain. Installed the floor drain in the pool and attached a 2 PVC pipe to it. Where I installed the pond liner has somewhat of a slope to the ground but I only buried the liner about half in the ground. I then sloped the ground up to the edges of the pond. I put cinder blocks around the drain and pipe for support under the liner. I then ran the 2 PVC pipe out to ground level where I put a 2 plug on the end of it. All I have to do is remove the plug and the pond drains in a matter of minutes. I hose down the pond liner washing everything out the pipe and then put the plug back in and refill the pond. I also have a small pump in the pond to circulate the water which helps keep it from getting stagnate. I change the water once a week or as needed. I put some large rocks in one end of the pond for the ducks to use to get in and out. They also like to stand on them to rest. Im sure its not the perfect pond but seems to work for me! I still have to finish the area around the pond as it is still bare ground and they love the mud they make!