DH wants to put a pool in the garden - a sort of natural pool for swimming but filtered by reeds/gravel (I think - haven't really listened to the technical side of it all). I think he's bonkers, that the maintance costs will be through the roof & it will be a financial drain! He genuinely would use an unheated pool all year round, I might do, the kids would use it on hot days... anyone done something like this?!