How Much Electricity Does My Fish Tank Use?

How Much Electricity Does My Fish Tank Use?

Taking care of our fish requires the use of electrical equipment such as filters, heaters, lights, and air pumps. These various pieces of equipment are designed to provide our fish with oxygen and stable water parameters. 

Unfortunately, all pieces of electrical equipment used in fish tanks will have an associated power consumption, known as wattage. The wattage will dictate the overall running cost of that piece of equipment. By adding the various wattages, we can better understand the overall running costs of our fish tanks, by the hour, day, month or even year.  

With electricity prices constantly fluctuating in the UK, it is a good idea to check we can afford the costs associated with keeping our fish tanks in great condition. 

Read on to find out more… 


How much will it cost to run my fish tank?

If you own or are looking to purchase a tropical fish tank, the power consumption will likely come from your heater, light, and filter. Let’s use some examples to better understand the running costs of some popular aquariums:

A Fluval Roma 200 comes with a 200W M-Series Heater, 21W LED light and a 12W Fluval U4 filter. The total power consumption assuming everything is on will be 233W. However, we can reduce this figure by assuming the heater will be on half the time (when the thermostat kicks in) and the lights for half a day. That reduces the overall estimated power consumption to 122W. 

The average cost of electricity in the UK is currently 27 pence per kilowatt hour (November 2023). In essence this means you will pay 27 pence for every 1000 watts of power used in an hour. Using the estimated wattage of the Fluval Roma 200 (122W), it will cost little over 3 pence to run this fish tank for an hour, which equates to 79 pence per day, and £288.55 for the year!

Now let’s use a smaller desktop aquarium as an example. The Juwel Primo 70 comes with a 50W Aquaheat Heater, 8W Novolux LED Light, and 4.4W Bioflow One Filter. Total power consumption of this equipment equates to 62.4W, but as mentioned previously we can reduce this to 33.4W by assuming the heater and light aren’t on permanently. Running costs on the Juwel Primo 70 would therefore be less than 1 pence per hour, 22 pence per day and £80 for the entire year! 

Of course, there are other factors to consider when calculating the running costs of our beloved aquariums. Realistically you will not have the lights on for half a day. We recommend you keep your lighting on for no longer than 8 hours in a day, to reduce algae growth. Also, take advantage of the dimming settings of your LED lighting if available as this will also reduce the power consumption. Fluval AquaSky LED lights and Fluval Plant Spectrum LED Lights both have dimming capability, which is why we recommend these fish tank lights to all our fellow hobbyists. Additionally, the ambient air temperature will affect how much the heaters turn on. On warm summer days it is likely that the heater will turn on very little. Likewise, if you use central heating systems in the winter this will provide additional warmth to fish tanks meaning the heater is used less.   


How to lower your fish tank running costs?

There are several things we can do to ensure our fish tanks are cost effective to run. The first and easiest is being smart when purchasing a fish tank. You will want to consider your own personal budgets related to running costs and shop accordingly. Pay careful attention to the wattages of the equipment included as they’re often not equal depending on the manufacturer. Go for the most economical option!

Be sure to purchase a fish tank which comes with LED lighting rather than fluorescent lighting. LED lighting is much lower wattage than fluorescent lighting and will also last much longer. If you are looking to swap your existing fluorescent lighting to LED to save money, we recommend using the Interpet ECO Max Aquarium Lights which come in a range of sizes and can easily be mounted to a range of aquariums.  

Live aquatic plants demand a period of light every day to photosynthesise and grow. A 12-hour photoperiod can be reduced to 8 hours in a day which will reduce the running costs. Take advantage of dimming your aquarium lights when available. Many manufacturers now provide dimming as standard. Very few aquatic plants need exceptionally bright lights. We often find running LED lights at 50% promotes plant growth and impedes algae growth while increasing the efficiency of your fish tank. Win, win. 

The ambient air temperature where our aquariums are kept will impact the amount of time our heaters are switched on by the thermostat. By ensuring our homes are well insulated, we can further increase the efficiency of our fish tanks. Likewise, we can insulate our fish tanks a little, by using the likes of structured foam backgrounds, hoods, and lids. Anything to prevent heat leaching out of the aquarium will improve the running cost of your fish tank. 

Finally, you may wish to go for temperate/cold water fish and remove the heater entirely. There are several species of fish such as Fancy Goldfish, White-Cloud Mountain Minnows, Danios, Tiger Barbs, Corydoras and Plecostomus which thrive in cooler water. Removing the heater will substantially lower the power consumption of your aquarium, but you will have a smaller selection of species to choose from. Let’s use our Juwel Primo 70 example from earlier. By removing the 50W heater, the aquarium power consumption will now be reduced to around 8.4W. Yearly running costs would now be just less than £20 per year! That is some incredibly economical fish keeping costs. 

*Electricity prices may vary and differ from those quoted in this blog. The above rates do not include standing charges and VAT.


Energy Efficient Fish Tanks at Complete Koi & Aquatics 

We hope you have found the information in this blog useful. Hopefully it will help you better understand the costs associated with keeping fish.

Here at Complete Koi & Aquatics, we only stock market leading products which use the latest advances in technology to reduce running costs. We endeavor to provide fish tanks which utilise LED lighting and highly efficient pumps and filters. 

 If you would like to browse our fantastic range of quality fish tank products, click here

If you have any questions related to the running cost of a fish tank, don’t hesitate to contact us directly. We’re always happy to help fellow aquarium enthusiasts, so click here to get in touch today!

Shop the best aquarium products & accessories for your fish at Complete Koi today

For more information and advice on aquatics, check out the rest of our blogs…


The Ultimate Guide To Canister Filters | How To Safely Clean And Maintain An AquariumA Beginners Guide To Setting Up An Aquarium 


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