I got the vacuum siphon (with bulb - medium) from Petsmart to remove my water from tank to bucket but was thinking about how to get my fresh, treated water from second bucket to tank - besides dipping and pouring. Was in the garage and I had a fountain pump I bought about a month ago that wasn’t strong enough for fountain so I replaced it with a larger pump. Also had the hose that had not been used. Cleaned the pump and ran 3-4 buckets of water through it. I guess this should work to pump water from bucket to tank? It will empty 5 gallons in less than 3 minutes. About the same displacement as sink. It should work I guess........will be doing my first change on Sunday.