My opinion is always err on the side of safety when it comes to high wattage fish tank heaters. If they go bezerk when you are sleeping, or at work during the day, you can easily come home to fish soup
Please keep a very close eye on it and your tank.
46 Gallon Bow F/W: 4 - Zebra Danio's, 2 - Red Platy's, 2 - lg. Silver Dollars, 1 - Pleco (4.5"), 1- Gourami, 1 - Cory Cat, 1 - mystery snail, 4 - Cherry Barbs, 1 - Black Molly