Best heating option for moderalty large water volume

[ca1ore]

Also depends a lot on what your tank is made from. My current 450, with 1" acrylic walls, requires less total wattage than did my prior 265 with 12mm glass walls. Imagine plywood would be even better.

 

[Feet4Fish]

I also have 1 inch acrylic walls so pretty good insulative property.

 

[maroun.c]

In the same boat, my setup is a 400 G at home and connected frag tanks and sump in a non heated basement. been struggling with 2500-3500 w (and we use 220V so that doubles up I believe on 110V) of heaters non stop Dec-MAr every year. the only break the heaters get is when halides turn on.
been considering a Titanium heat exchanger or just heating up the basement.
to make it worse I have to vent the basement to avoid humidity issues so that adds up a lot to the heat loss. last year I resorted to running dehumidifiers set at 60-65% humidity levels which decreased a lot the amount of ventilation and heat loss and made it easier for heating.