Blue

As heaters can and will fail.Happened to me this weekend with tropical tank.Rather than put one heater in your tank of the correct wattage.Purchase/put in two heaters which ammount to correct wattage required.Example tank requiring 300Watt heater place in two 150Watt heaters.That way should one fail there is less risk of fish loss and less likely hood of your fish being boiled alive should a heater stick in the on position.