is the one I have. I had the same issue when I was going out of the country for a month. I had friend stop in to feed, but top off was too much to ask for. I got a 45 gallon BRUTE container that I fill about every 3 weeks.
When I had a FW
tank (years ago) there was a product called the Merdian (sp?) Water Changer. It had two hoses that were connected. One hooked to the faucet, the other was the drain. At the tank, it had a spring loaded attachment clip. The drain line had a screen around it. The fresh water line created a jet stream of aerated water back into the tank. Forcing that much air into the water removed the chlorine. The hose ran about 3 gallons per hour into the tank. I would hook it up for an hour two every week and had a 10 - 20% weekly water change while I watched TV.
I no longer see that product on the market probably due to the increased use of chloramine.