Just bought a foreclosure house in central illinois. It has a pool, not sure what kind. It is inground and what looks like concrete walls. No liner. Its pretty cracked from whatt I can see. It is half empty and its like a little lagoon. Algae and all kinds of crap in there. I was told by the neighbors that it leaked and never really worked right as long as they remember. Trying to decide how to bring it back to life. The house has been vacabnt for atleast a year.

1. So my first question is it gets pretty cold here so do I drain it all the way right now and clean it out and fill it back up without replacing the liner to see if it really does leak?

2. Do I drain it and put a liner in it just to be safe and call it good?

3. Do I drain it and work on it next year? The only problem is, I have been doing some research and they say to never leave a pool empty over winter? I do get some colllldddd winters and dont want the walls to cave in.

4.Do I just fill it up right now and clean all the crap out of it with some sort of filter?

Any help is greatly appreciated. Thanks