Winter heater advice for 24 gallon saltwater

[Petrichor]

I need some advice on heaters for a new, still cycling, 24 gallon saltwater tank. Right now I have an older Eheim Jager 75w heater, but I'm not sure it will be enough for the tank for winter. You see, I previously lived in the SW United States and never had to use a heater on my saltwater tank as, well, the desert did that for me. Now I'm living in Ontario, Canada and I'm wondering how a much colder winter will affect my tank temps?

The tank is located in a finished basement near an exterior wall, but not near any windows. Would my 75w heater be enough, or do I need to buy something higher powered? I know having two heaters is generally preferred, so would a second 50w-75w be fine?

If I do buy one I'm looking at the Aqueon submersible heaters as they're within my budget. Any opinions?

 

[Scurvy]

Room temp will probably be the deciding factor but assuming you keep it around 72/73 degrees I would expect the 75w to be enough. My 125ish gallon system sits on a concrete slab next to sliding glass doors and does ok with (1) 300w heater in MA winters.

General rule of thumb is 3w/per gallon.

 

[Scurvy]

My ATO container has frozen before though in a severe cold stretch

 

[W1ngz]

If you're buying heaters and have what you call an 'old' heater already, I'd replace the single 75 with a pair of 50s and a simple temp controller. If the budget is really tight, keep the 75 and put it on separate controller, and plan to add a 50 for some redundancy.

If one fails, a single 50w probably won't maintain an ideal temperature, but should be able to maintain a minimum safe temperature provided normal room temp.

 

[Jonathan Gamboa]

I’d go with what w1ngz suggested. Exactly what I do. Works great and a good safe guard to give you some time if anything fails.

 

[Petrichor]

Thanks for the replies! I didn't know temperature controllers were a thing, but they sound great. I can't afford two new heaters and a controller all together though, so I will definitely add it to the future upgrade list and stick with my 75w Eheim until winter. I should have enough by then to get 2 new heaters and the controller if I don't spend all my savings on coral by then!

 

[W1ngz]

The 75 alone should be fine. Add the controller as soon as you can to protect against a 'stuck on' situation that cooks the tank. It's likely to be easier to calibrate also, and then later on when you have a few more bucks, you can add a 50 for a little more redundancy.