Heater for a 55 gallon tank

[Mudfrog]

I just ordered a new heater for my 55 gallon tank, it is a 200w, do you think that will be suffice or will I probably need to purchase another one?

BTW it is a non submergable heater if it makes a difference.

[TankGirl]

I would purchase another one, to have a backup, and you can place one on each side of the tank for more even heating.

[Maillis]

I use 2 150 watt heaters in my 55 but a 200 placed in the center of the tank should be ok if the room temperature isn't more than about 5 degrees lower than the tank temp you want.

[XXFirefighter]

250 watt Ebo here.. not one issue..
I'd get a quality 2nd