I know this is crazy, but has anyone ever tried one of these? (they're meant to go under your kitchen sink to chill drinking water.) New they cost as much as an aquarium chiller ($300-$600), but I found one used and supposedly working for $30. It has a control knob for how cool it gets, doesn't sound very accurate, I'm sure it would take experimentation to get right, but my main concern is if it can handle salt water. I would put an extra inline filter in front of it for sediment.