Question: are fish tanks expensive to run?
Answer: On 24 hours per day for oxygen in your fish tank. ... 5.04 kilowatts times 12 cents per kilowatt = $0.60 cents per month to run your powerhead for your 50 gallon aquarium powerhead. The total electric cost of running a 50 gallon aquarium with live plants or coral is $9.72 dollars per month.