FINALLY after 3 years or so I have an auto water changing system installed on my 10' tank!
I am now putting 24 gallons of fresh water into the tank every single day, all automatically and I don't have to do a single thing.
This was a bit of a challenge here because there is no water near the tank and its nowhere near a floor drain either. New neighbour on my street is a semi retired plumber, YA solutions! He picked up a pump for me that holds about a quart of water in the bottom of it. So water overflows from my sump into this pump, then when it hits the float in the pump it gets sent away about 30' and ties into a sink drain. We also ran a whole new line bypassing my water softener to the tank (60' or so of line). happy happy, doing water changes on this tank was always a pain in the butt and involved 2 x 50' pythons yuck.
No worries now about the sump ever running dry, or if I forgot to change the water. Now to get the tank in my living room on the same setup