It's no secret that I've just very recently stripped down a 120g and a small hex tank in my fish room. I now know exactly what those two tanks were costing thanks to monitoring my smart meter before and after. I was looking at £750 a year to run them both! It was a shocker I can tell you.
The biggest wedge of that was, as you say, heaters. But also filters, pumps and powerheads all add up too.
Before I took the plunge and stripped them down I toyed with the idea, although only momentarily, of heating the fish room itself by means of keeping my wood burner stoked up constantly in the next room (with free wood from work, win win all round). I could have taken every heater out of my tanks, including the 3x300w heaters in my 360.
It would have been a huge saving over the year but the very nature of the woodburner means it goes out when not fed, ie during the night. The temps in my tanks, just by relying on the woodburner, would have been all over the place, which put me off. And there's no way on god's earth I'll fork out money for coal to keep the fire in all night, lol.
The sad part is, you can insulate your tanks all you like, you can turn the temps on them right down to borderline acceptable, but the way the prices are spiralling means you're still gonna get heavily stung on electricity usage.
You could think about going the native route and put your heaters away, good saving there, but you'll still have other ancillary equipment to pay for. Or you can do the unthinkable and downsize, as I have.
The coming months are going to be make or break time for many hobbyists.
