saving which way?
we went over this on a aus forum, came down to solar energy, heat the water using solar water heater setup correctly (complicated as hell) heat the room over tanks, insulate as much as possible, dont waste old water and try to diy as much as you can. These where all on the topic of fish rooms not single tanks, I dont think there is anyway you can really keep a single tank down apart for using sponges over canister etc but the difference is little
we went over this on a aus forum, came down to solar energy, heat the water using solar water heater setup correctly (complicated as hell) heat the room over tanks, insulate as much as possible, dont waste old water and try to diy as much as you can. These where all on the topic of fish rooms not single tanks, I dont think there is anyway you can really keep a single tank down apart for using sponges over canister etc but the difference is little