WOW! I have not run into an issue like that. I have never had a problem with the one tank on the rheostat. Honestly, I never planned on keeping the setup like that, but it was a rescued BP and I needed a tank setup fairly quickly. I had everything I needed except a thermostat, so I ran out to Petco and picked up the rheostat (it was most cost effective at the time), and since it has yet to fail me, I figured I would stick with it for now![]()