The cost of electricity can vary wildly across the US. Even within the same states, you can encounter a range of different costs and approaches to billing those costs. Some areas are billed with flat rates, some have tiers, it can vary based on time of day or season too. It is all just very specific to you and your tank.

As it pertains to estimating the ongoing costs of running an aquarium, electricity is something you just cannot overlook. It's something every aquarium needs and the costs can be significant. The larger the tank, the more power you're going to consume. 

Estimating Your Monthly Electrical Costs For The Aquarium

#1 - Find Out How You're Billed

Using a past electrical bill or researching with your power company, you can find out exactly how you are billed. In most cases, you are charged a particular fee per kWh - kilowatt hour. 

  • kWh (kilowatt-hour): How much power you're household is consuming per hour.

The cost per kWh can vary depending on the time of day and/or month of the year but might also be a flat rate depending on where you live. Sometimes the cost per kWh is tiered based on total consumption where you get rewarded for being "energy conscious". The energy bill will show how much kWh was measured and at what cost per kWh you were charged.  

#2 - Find Your Cost Per kWh

If you're lucky to have a single cost per kWh, it's pretty straightforward and will be listed on your bill. If you are in a camp where the cost per kWh varies, you can just make your life easy and calculate the average. 

Calculating Your Average Cost Per kWh

  1. Using a previous bill, locate the total number of kWh used in a single month or billing period.
  2. Find the total cost of your bill. Deduct any processing fees or one-time charges.
  3. Divide the total cost of your monthly bill ($) by the total number of kWh you used to get the average cost per kWh.

The average cost of power in the USA is just above $0.10 per kWh. It can be as much as $0.70 and as low as $0.05 per kWh. 

#3 - Measure How Much Power Your Tank Uses in kWh

This step takes a little effort because most of you probably don't track the power usage of your tank. The easiest approach is to use something like the Kill-A-Watt surge protector which is a great tool that not only serves as a power center with 10 outlets but also tracks your power consumption in kWh. Aquarium controllers like the Neptune Systems Apex or a Kilowatt Meter can also be used to monitor power consumption in kWh.

Track consumption for at least 24 hours to get your total kWh consumption per day or just run it all month long to get the total kWh for the month. Remember, all the equipment needs to be plugged into that kilowatt meter. You can just as easily track equipment individually and add the kWh of each device together. 

How To Calculate kWh Using Wattage

Alternatively, you can calculate the kWh using the total wattage of each piece of equipment on your tank and how long it is turned ON. This can be a little misleading just because each device is not always going to be using the maximum wattage when it is ON. That said, it will give you the maximum possible consumption and therefore maximum cost. 

kWh = (watts x hours of ON time) / 1000

  1. Find the total wattage of each device on your tank
  2. Multiply by how many hours that device is ON in a 24 hour period
  3. Divide by 1000 to get kilowatts hour 
  4. Add the kWh from each device to get a total kWh for 24 hours
  5. Multiply x30 to get the total kWh for the month

#4 - Calculate Total Cost

Here, you can get the final estimate of how much the electricity will cost to run your tank each month. Simply multiply the total kWh you are using per month x the cost ($) per kWh.  If you want an annual cost, multiply the monthly cost by 12.