500 watt digital titanium water heater
This heater features an external digital thermostat that doubles as an always-on LED thermometer. The electronics stay out of the water and can be mounted for quick visual checks. The temperature sensor is on a separate line from the element for more accurate readings. It plugs into any standard 120 volt outlet and you can put up to three of them on a standard household 15 amp circuit. This heater comes with a one year warranty from the manufacturer.
Electrical usage note: This heater uses about five cents worth of electricity per hour when it is actually heating and almost nothing when it is in stand-by mode. Assuming that your conditions require that the heater cycle on for one-third of the time, or a total of about eight hours per day, this unit will cost about 12 dollars per month to operate.
Tip: Preventing warm air from escaping the building or greenhouse will significantly decrease the cost to operate this or any electric heater.
200 watt digital titanium water heater
All of the same features as the heater above in a more gentle 200 watt model. Perfect for breeding colony aquariums and fry tanks. You can plug up to seven of these on the same 15 amp circuit without tripping the breaker. Handy for keeping rows of fry tanks at the optimal temperature.
Electrical usage note: This heater uses about two cents worth of electricity per hour when it is producing heat. Cycling on and off for 24 hours, with a combined average of 8 hours in heating mode, it will add about $4.80 per month to your electric bill.
Comes with a one year manufacturer's warranty.