Okay this may seem trivial but what method should one use as an auto top off without a sump? Could you use an auto doser run into a 5g water jug and could this drip into the main tank. Are those auto dosing pumps strong enough to move water from beneath the tank into the main display. I would like to try something like this and mix in calcium etc into the water so that it goes in an auto top off? I don't have room to put anything above the tank......just curious how others do this????