Newbie here. We are very close to closing the deal with a pool builder on an 18 x 37 inground pool. He's trying to sell us the Nature 2 system, but I've read nothing but negative things about this system. We have no clue what to use. Can anyone here help us? We currently have an above ground pool with the Perma Salt system and HATE it. So, we don't want salt, we know that. Any advice and input you have is greatly appreciated!