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Green Fish Tanks: Eco-Friendly Aquarium Cleaning Hacks

One out of every 12 households has some type of aquarium. If you’re one of those households, is your fish tank green? We’re talking about the algae that build up inside the aquarium as well as your cleaning methods. Keeping up a fish tank can consume thousands of kWh of energy per year; that’s more power than your refrigerator uses.

Plus, you want to use eco-friendly chemicals to clean your fish tank so that you don’t harm the fish inside. Here are some ways to maintain your fish tank so that it doesn’t hurt the environment.

Start With a Small Tank

Bigger isn’t always better when it comes to maintaining an eco-friendly fish tank. If you’re a novice in this arena, start small. We don’t mean that you should buy a fishbowl. Those aren’t a suitable environment for your fish.

Even though fishbowls seem more convenient to maintain because you don’t have to buy any fancy equipment, they’re challenging to manage. The chemical and physical composition in a fishbowl can vary wildly. If you can’t keep the atmosphere stable, your fish will not thrive.

Many fishbowls don’t have a large enough area to absorb oxygen at the water’s surface. Therefore, fish in bowls slowly suffocate. Fishbowls also lack proper filtration. Filtration is essential in small vessels, however, because the water quality is so poor.

Therefore, if you do start small, choose a tank instead of a fishbowl. You can outfit a tank with filters and pumps to keep them working correctly.

A 10-gallon tank consumes only about 90 to 120 kWh per year of energy. That’s the equivalent of the amount of energy that a coffee maker uses. A huge tank consumes a massive amount of energy, however. Saltwater tanks also require more power than freshwater tanks.

You’ll get the hang of maintaining your small tank reasonably quickly. Once you’re comfortable, you can move onto bigger sizes.

Self-Cleaning Fish Tanks

Self-cleaning fish tanks are a great start if you’re experimenting with a small container. They come in many forms.

Some, like the NoClean Aquarium, work off of the principles of physics. Dirt sinks to the bottom of the tank, where it is trapped in a reservoir. A tube runs from the bottom to the top of the tank. The tube drains through a pipe on the exterior of the tank.

When you pour clean water into the container, it pushes the contaminated water up the tube and out the faucet on the side.

If you get a self-cleaning fish tank that works using this method, you’ll need to change the water as frequently as every two to three days. If you don’t, you can throw off the balance of minerals in the water, which can be dangerous for your fish. However, you don’t have to use harsh chemicals or remove the fish from the tank to replenish the water.

Use Bio-Stones

Adding different elements, such as stones to your aquarium creates interest and gives fish places to hide. Some products also clean your tank.

Products such as EcoBio-Stones contain cement and volcanic rock. These items are porous and filter some of the water. Manufacturers also infuse them with friendly bacteria, which respond to the organic waste in the water. The beneficial organisms help keep your tank clean by:

  • Clearing up cloudy water
  • Reducing odors
  • Accelerating the nitrogen cycle

These products mimic the action of live rocks, which also stabilize water chemistry, deliver bacteria into the water, and help balance nitrogen. However, live rocks that are sourced from the wild are not eco-friendly. If you put live rock in your fish tank, make sure that it’s farmed in an environmentally friendly manner.

Clean With Plants

Plants have a similar effect as rocks in an aquarium. They add movement, make the aquarium look lively, and help the fish feel as though they’re in a natural habitat. Plants provide shelter for the fish.

Plants absorb carbon dioxide and nitrates that your fish put out into the water. They also emit oxygen. They’re natural filters that help keep your aquarium healthy.

Plus, plants take nutrients from the water to survive. Any algae that might grow in your tank compete with decorative plants for these nutrients. When you have enough plants in your aquarium, the algae may not get enough nutrients to survive, and your tank will stay cleaner.

But you have to choose the right plants for your needs. If they’ll go in the tank, make sure that you can completely submerge them. The plants must also be compatible with your fish and water type.

Some of the most resilient and low-maintenance aquarium plants include:

  • Echinoderms
  • Lilaeposis
  • Anarchies
  • Anubis

Try an Aquaponic Fish Tank

In an aquaponics fish tank, the fish and the plants have an interdependent relationship. The plants grow in basins above the tank, and the fish swim around below them.

As the fish swim around, they eliminate waste into the water. The tank’s pump pulls the waste out and deposits it into the garden at the top. The plants use the waste as nourishment to grow, and the water, which is now filtered and waste-free, returns to the tank.

This self-sustaining ecosystem doesn’t require a lot of maintenance. It looks great and can help you grow a flourishing indoor garden.

The best plants for aquaponic fish tanks include those that would do well in an aquaponic system, such as:

  • Herbs
  • Wheatgrass
  • Lettuce
  • Leafy greens

Eco-Friendly Aquarium Filters

There are many aquarium filters on the market, and you might wonder if using them is eco-friendly. Canister-style cleaners contain filtering media that pull contaminants out of the water to refresh the tank. Unlike power filters, which have replaceable cartridges, canister filters must be washed regularly.

Using a canister filter can produce less waste because you don’t have to throw out the biological media. That’s a good thing because the filtering material holds onto beneficial bacteria that help your fish tank stay clean.

You should keep the filter material wet while you’re cleaning out this type of filter, though. Doing so will help it last longer and retain its biological properties. Change your filter media once it starts to disintegrate, which might happen every year or two.

You can also try using a water purifier cube. These sit near the water inlet of the pump and filter contaminants. They’ll keep the water clear, maintain cleanliness, and balance the pH levels. Many water purifier cubes extend the life of your fish and reduce odors in the tank.

Use Fish Tank Gravel

The stones that you place on the bottom of your aquarium aren’t just there for looks. While aquarium gravel is aesthetically pleasing, it also makes the environment more eco-friendly.

One of the most important reasons to use aquarium gravel is to provide a place for friendly bacteria to grow. Colonies of beneficial microorganisms clean your fish tank of animal waste, debris from plants, and uneaten food. Although bacteria can grow without gravel, they’ll maintain adequate numbers for a healthy tank when they have the right habitat.

If you don’t have gravel in your tank, you’ll notice that debris builds up relatively quickly on the base of the aquarium. This can be harmful to your fish because it throws off the ammonia and nitrate levels. You’ll need to change the water more frequently in a bare tank, which reduces the environmentally friendly appeal of your aquarium.

The substrate also enhances water chemistry. Certain types of gravel, such as coral or oyster shell, can make the water harder, which is preferable for some types of fish.

Some experts believe that brightly colored gravel can stress out fish. That’s probably because the animals aren’t used to seeing those hues in nature. If the substrate is artificially painted, the color can flake off and harm your fish. Choose natural materials whenever possible for the healthiest tank.

Get an Algae Eater

Many aquariums develop algae from time to time. This type of plant can leave a furry green film on the inside of the glass. It may make the water cloudy and cause the tank to smell.

Different types of algae can plague your aquarium. These plants proliferate when there’s a lot of waste and food in the water. Therefore, cleaning your tank properly is one way to keep algae at bay.

You can select a high-quality filter that’s designed for fighting algae. Keep your filter clean so that it can work efficiently.

You can also give your fish higher quality food, which they are more likely to eat without leaving leftovers. Adjust the feeding schedule to minimize food waste.

Turning off the aquarium lights at night will also stop algae from undergoing photosynthesis during those times. It won’t grow as rapidly. Plus, you’ll save money on your electricity bill.

If your fish tank tends to develop algae, though, you can use nature to take care of it. Algae eaters are fish that consume this plant material. While you’ve probably seen them clinging to the inside of the glass in commercial fish tanks, not all algae eaters look the same.

You need to get an algae eater that is suitable for your water and tank type. The animal should also be compatible with the other organisms in your tank.

Some of the most common algae eaters include:

  • Twig catfish
  • Siamese flying fox
  • Mollies
  • Malaysian trumpet snail
  • Nerite snail
  • Amano shrimp
  • Cherry shrimp
  • Ghost shrimp

Use a UV Sterilizer

Many people use UV sterilizers in saltwater and freshwater fish tanks to reduce parasites, combat algae growth, and fight bacteria. UV sterilizers involve using tubes of ultraviolet light to damage the DNA of single-celled organisms that might be damaging your ecosystem.

UV sterilizers can be standalone products. They can also connect to your canister filter to get rid of any pathogens that might return to the aquarium via the water outflow.

One of the best things about a UV sterilizer is that it doesn’t use harsh chemicals. Also, it should protect the beneficial bacteria if you’ve set up your tank properly. Friendly bacteria live on surfaces, such as rocks, plants, and gravel. As long as these useful bacteria don’t get pulled through the filter, they’ll stay alive to work their magic.

UV sterilizers may stress out your fish at first. However, they’re safe and won’t harm the animals. Make sure that you follow the manufacturer’s instructions when using this type of equipment, and purchase the right kind for your aquarium.

Sourcing Your Fish

If you’re really concerned with having an eco-friendly aquarium, you should be particular about sourcing the fish. Wild populations of fish are often harvested from the wild. They’re pulled from their habitats in abundant coral reefs to be sold in pet stores.

Approximately 80 percent of these fish die as they’re being captured and transported. Furthermore, the companies that trap these fish spray cyanide into the reefs, damaging the habitats and putting pressure on natural fish populations.

About 90 percent of freshwater aquarium species can be bought from farms. These types of fish are often considered to be a more environmentally friendly option than wild-caught fish.

It’s the saltwater fish that pose a problem. Most of these cannot be farmed. But hobbyists love the look of brightly colored saltwater fish. If you have a saltwater aquarium, use reputable sources to purchase the animals. Don’t buy endangered species.

Also, make sure you know what the fish are supposed to look like. Many sellers will dye the fish to make them even more vivid. However, this process leaves the animals susceptible to illness.

The Marine Aquarium Societies of North America can point you in the right direction for sourcing fish using ethical practices.


If you’re excited about your aquarium hobby and are concerned about its impact on the environment, you can practice in a way that’s gentle on the planet and your miniature ecosystem. Do some research to make sure that you’re using products that are compatible with your setup. Once you get on a roll, you’ll probably get hooked on all of the options for eco-friendly aquarium cleaning.

Jason Roberts
About Jason Roberts
Jason is an aquarium fanatic that has been a fish hobbyist for almost three decades.

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