I'm replacing evaporated water frequently enough that I'm convinced of the advantage of using an ATO unit & reservoir.
But every mention I've seen of one seems to imply that they are always paired with a sump. Does that mean an ATO cannot be made to work in a sump-less system?
But every mention I've seen of one seems to imply that they are always paired with a sump. Does that mean an ATO cannot be made to work in a sump-less system?


