Basement to living room the easy way and the harder way

[Sk8r]

We have a living room with 2 tanks, one salt, one fresh. The salt feeds water via a couple of 1" return holes in the floor up from the sump, which has a topoff (minor floor repair if ever not needed)
but....
The discus freshwater tank, a 50, that evaps a gallon a day, is 20 feet in the opposite corner with a doorway between (no hiding anything along the wall) and next to a fireplace and a brick outer wall. We puzzled and puzzled what elaborate methods it would take to get a hose to that tank (rather than climbing a flight of stairs with 5 gallon buckets).

Bingo! there is an ac return vent right beside tha tank and it crosses from the furnace, to that ready-made hole in the wall. It's thin ducting beyond. So we drill up into that duct right where the vent is, insert a quarter inch hose that we can put at will into a 5 gallon bucket upstairs, beside the tank, and use a simple pump to do the lifting. If we source the pump and hose in a 5 gallon bucket hand-carried from the sump's ro/di soruce---and pump it up to another 5 gallon bucket in the living room, we never risk an overflow and the problem of monitoring for that between living room and basement is non-existent. The hose will simply run through the slats of the vent and lie useless and empty in between fills.