What is the best way to keep tanks to hold heat in an unheated basement. It's sort of heated on the other side of the basement but my heaters are almost always on. Ive lowered my lemps to about 78* when i usually keep them at about 82*. These heaters being on all the time is just racking up the bill. Two of them dont have tops but i have rigid insulation over the top so i guess that helps a little. Any help is appreciated. Its also a concrete floors but none of the tanks are on it. The 29g is close to sitting on it though..