How Much Will a Pet Fish Impact Your Water Bill?


Compared to a cat or dog, allowing your child to adopt a fish may seem way less daunting—but is the worry of an increased water bill holding you back? Between filling and cleaning a water tank, adding a fishy friend to your household may sound like a burden. We’re here to bust some myths and break down how much you can actually expect your water bill to be impacted (spoiler alert: it’s not a lot). 

Finding the right fit 

The first step of any pet adoption process is finding the right fit. Read up on different species of fish to ensure you choose the best option for your child, as the level of care ranges for different types. It’s also very important to choose the right tank for your fish, which in turn will affect the amount of water you will use per month depending on size and filtering abilities. You can either choose a fish first and research into the perfect tank, or if you’re still weary on water usage, choose a smaller tank and find a fish to fit!

How often to clean

The monotonous process of cleaning and replacing water in an aquarium may put you off on the idea of becoming a fish parent, but the reality is far easier than you’d suspect. The average recommendation is to implement a 30% water change every 2–4 weeks. But, once again, this may vary depending on species and size of the tank. That’s why it’s important to do your research! 

Bonus: It’s suggested to try not to change more than 50% of the water, because doing so can remove helpful bacteria that has grown within the tank or bowl.   

Teaching responsibility 

The truth of the matter is that you won’t know the exact expense of adding a pet fish until it’s adopted, especially with all of the different possible variations of fish and tank size.

However, why not use this moment to teach some important lessons in responsibility to the kids? Pay attention to the small difference in your water bill after adopting a fish, which usually ranges from a few cents to a couple of dollars. Then, consider asking your child to use a portion of their allowance or lemonade stand earnings to cover those expenses. This will teach them accountability, and they may even feel like proud fish parents with real responsibilities.  

Bottom line: if the only thing stopping you from getting a pet fish is the threat of a severely increased water bill—no need to worry. Very rarely will a little fishy friend add that much to your expenses. Either way, you can use it as a valuable lesson for your kids. So go ahead, do your research, and bring home the newest member of your family!