Wait for black Friday, buy a generator inverter, less noise and powerfull, they can run for long hours and they won't have the power peaks that it could burn and kill some of the sensitive equipment like controllers and small voltage items that work in your tank, they're costly too, but normally they keep a good reselling price if you decide to get rid of it one day.
Yes, you could get might be a lot more power from a regular generator, but a hell of a noise and power peaks will come with it, there's might be a solution for that, I don't know, someone else can chime on that.