I am trying to find ideas for an auto top off on a tank with NO sump. I have a Litremeter III dosing pump that can be adjusted to add any amount of water throughout a day. Only question is if the tank does not need topping off I can I stop the pump. In the past I had a Ultralife float switch in the sump that shut off the pump. My problem is a new tank may not have a sump so I can I achieve ATO?