New tank needs a heater...but what size?

[Lessgo]

I have order a new 300 gallon tank (72x30x32) and it's getting a 135 gallon sump.
It's going in my basement, and the closet window to the tank is 25 feet away. It will have no chance of getting natural light.
The tank will be lit by 3 x 360 kessils.
Skimmer is a reef octopus sss 5000
House temp is usually 69 to 71 degrees

But where I'm at a loss is what do I need for heaters. I've had some tell me I need dual 400watt heaters, all the way up to 1800watts of heaters.
Can anyone help me as to what I need for heat.

Thanks for the help