So you decide that it is time to get rid of the resource hog living in your backyard. Good choice.
So now what? Fill, convert, or something else?
I am not sure there is a "something else", but if there is, good luck.
You basically have 2 choices with a lot of options for either of them.
1. Fill it. This is the simplest of the choices, so you would think. Remember all that dirt that came out of your backyard? It now has to find it's way from the street back into the hole. Are you ready for what that might entail? If your lucky, there isn't any landscape between the two. If your not so lucky, and most of you won't be, be prepared to re-landscape, re-build some fence, and possibly re-pour your concrete walkway. A BIG tractor will be your worst nightmare for a day or two. Back and forth, load after load. Squashing everything in its path.
Some companies have huge machines that will lift dirt up and over without the tractor mess. If you have a lot of extra cash lying around, this is the way to go if you decide to fill it.
Be prepared to pay anywhere from $10,000 to $20,000 to have your pool filled. No landscaping, just fill dirt into the hole. Then you will have to landscape, so add another $2,000 - $20,000 to it.
2. Convert it. You have a huge hole in your backyard, already dug and paid for. Why would you want to fill it? There are so many things you can do with a pre-dug hole the size of a swimming pool. Anything from a bomb-shelter to a "Green" guest room. Another great idea would be for a greenhouse. Your imagination could go wild with all the possibilities. I spent about two weeks looking for the right solution. I wanted something nice, inexpensive, and most of all, earth friendly. A contractor wanted $15,000 just to fill the pool with dirt. I wanted to spend less than that. It really came down to either a "cold storage" room or a pond.
My decision and how I got there
At first I didn't like the pond idea. It seemed exactly like a pool. I mean, what would be the difference? The answer came a few days later when I happened upon a site showing the wonders of aquaponics. I didn't really pay too much attention at first. But as I was looking at the huge vegi's being grown out of the grow beds, I noticed that the grow beds looked just like a biological filter that I had looked at earlier in the day. That's when it hit me, what if I used grow beds for my pond filters? They are exactly the same thing, just one grows vegetables, the other aquatic plants. So I started looking around the net for somebody that had done this. Surely someone has done this before, right? Well if someone has, they haven't spread the information to anyone. I looked for days, and came up empty. So this is it, the first(as far as I know) aquaponic pond built from a swimming pool.
I started thinking about what I would need as far as money. I was figuring about $5000 if I did all the work myself. As it has turned out, it was a lot less than that. I am roughly guessing it has cost about $3500 total. I will be rounding up all the receipts and getting a closer total, but that should be pretty close. So compare that to any other option and you will find this is the least expensive option, by far.