[pandacory]

So clearly led lighting is the most energy efficient in terms of watts/par, but what about other equipment?

Is an Inline heater more efficient than an in tank heater?
Is one type of powerhead more efficient than another (design, not flow related)?
Is a canister, hob, or sump the most energy efficient for a given filtration capacity?
Does glass insulate the water column from temperature changes better than acrylic?

 

[bsmith]

Im pretty sure that the Eheim Classic line of canister filters use the least amount of energy in comparison to other canisters rated for similar flow and tank size suggestion.

 

[DarkCobra]

The Hydors and clones seem to have much higher flow per watt than traditional powerheads.

Acrylic is a better insulator than glass.