3.5G tank. Any heater recommendations?

[Emmahlee]

My heater has been working well until the cold hit.
now it is struggling to keep my 3.5 gallon tank warm. During winter it will get down to -8 degrees Celsius. & my house does not have central heating.
Do you have any recommendations on which heater I should buy??
I need a good quality heater that isn't too pricey.

[Micho]

Elite Submersible Heater 25w, it's adjustable and Elite brand is so reliable.

It'll heat anything up to 5g.

[Emmahlee]

Thank you! I will have a look around for one.