I had to drain my pool. I was trying to use well water, being cheep, but OMG I had a black pool less than 24 hrs after filling it. I used the filter pump to drain all the water and I got it down to less than 2 inches but it could have been better. First I just took the skimmer basket loose from the bracket and let it hang in the pool and I hooked the return line from the filter to a long piece of 1" PVC using one of the adapters so I could pump the water out to the street. I pumped the water down to well below the skimmer fitting in the pool and then removed the entire fitting from the side of the pool. I found that if you take the blue fitting that the strainer hose plugs into you can take the vacuum hose and stuff it inside the blue fitting and it's a pretty tight fit. I then put the vacuum hose through the hole where the skimmer fitting was and started a siphon into the pump laying the pool valve on the ground next to the pump so it was not the high point. This way it did not suck a lot of air into the pump. I then hooked the vacuum hose to the vacuum attachment in the pool and cleaned all the gunk and orange dirt off the bottom of the pool with the vacuum until I had the pool mostly clean. I then left the vacuum attachment in a low spot on and it didn't stop sucking water until there was just over an inch of water. Now I could have done better if I had thought about draining the pool when I was trying to make the bottom smooth. If I ever take the entire pool up again I will make a 2" deep depression about 2' around to create a low spot to drain all the water from the pool. I am pretty sure that it will not effect the pool sides as long as I make the sides of the depression gradual.
bottom line. well water bad. And put a Drain well depression in your pool.