How Much Electricity?

for the week of 6/3/98

Once they see the assortment of aquarium accessories that are plugged into the wall, many hobbyists wonder just how much their tank is costing them in electricity each month. Here's the basic formula:

Monthly Cost = (wattage) x (charge/kwh) x (hours/day) x 30 x .001

(wattage) can usually found on each item
(charge/kwh) can be found on your electric bill; residential is often .05 to .07
(hours/day) is how long the item is operating

For example, an aquarium pump might use 4 watts and runs 24 hours per day, so it's monthly energy cost would be:

4 x .06 x 24 x 30 x .001 = .17 or about 17 cents per month

Adding up all the items for a typical 20 gallon setup might look like this:

Item	Wattage	Hours/Day	Cost
Light	15	12	.33
Air Pump	4	24	.17
Power Filter	9	24	.39
Heater	100	4*	.72
Total			$1.61

* This number varies considerably depending on difference between room and aquarium temperatures. In cooler climates or seasons, the heater might run a total of 12 or more per day; in warmer situations, it may hardly run at all.

Larger aquariums will of course require somewhat larger amounts of energy, and it often pays to look into the wattage rating on items before purchasing them.

Submitted by: Jim Kostich

"Tip of the week" appeared regularly in 1999 and 2000.