Aquarium in garage

[Newbie1]

So I put my salt water aquarium 55gal in the garage. It has a 20 gal sump. I have about a 7 gal ro reservoir. I had two heaters in the sump and set at 82 degrees. The thermometer was in the display and it was 79-80. Today I see the temp at 77. So I put another heater. I don’t know if my ro which doesn’t have a heater, cooling the sump down when it fills up. Or if the garage is getting colder... or what.
What can I do to help and ensure the safety of the tank during winter? Should I put a space heater facing the sump? Another heater? What?

 

[lapin]

What size heaters? They might be to small to keep up.

 

[tehmadreefer]

First off where do you live that has winter weather? So depending g on that will depend on the size of heaters you need.

 

[ihavecrabs]

If you are in Kansas, I hope that garage is insulated and heated.

I made the mistake of cycling rock in my garage a few years back over winter and my heater never turned off while it was out there. $$$ on electricity.

 

[tehmadreefer]

Kansas, ya, um thats not gonna work out too well unless the above is accurate with insulated and climate controlled!

 

[MixedFruitBasket]

Why is 77 too low?