Aquariums at Home may earn an affiliate commission when you buy through links on this site. See footer.

Can Oscar Fish be Used in Aquaponics?

Aquaponics is a combination of aquaculture and hydroponics. It’s a form of organic food production whereby aquaculture water (created by fish waste) is ‘fed’ to hydroponically grown plants. From an aquarist standpoint, it involves using aquatic plants and animals to create a symbiotic environment. If you’re thinking of trying aquaponics, you may be wondering if Oscar fish can be used in the process?

You can use Oscar fish for aquaponics, provided they’re kept in mated pairs or small groups of no more than 5 in an extra-large aquarium. You must also use compatible plants like pothos or devil’s ivy that thrive in the same aquatic conditions (temperature, pH, hardness, etc.) as Oscars.

Now that you know you can use Oscar fish for aquaponics, let’s explore this topic further and in more detail. Together we’ll discover how aquaponics works, how to setup an aquaponics tank, what size tank is best, how many Oscars can be kept together, what fish make the best tankmates, what to feed them, and what types of plants to use.

So, if you’re ready to learn more about using Oscar fish for aquaponics – including both the pros and cons of such an endeavor – then let’s begin!

How Does Aquaponics Work?

Aquaponics involves keeping fish and other aquatic creatures in tanks and using their wastewater to feed organically grown plants and vegetables. The wastewater is pumped into grow beds. The roots absorb the nitrates and the water is returned into the tank – filtered, clean, and free of toxins. It’s the perfect way to create a mutually beneficial environment for both aquatic creatures and plants to thrive.

How Big of an Aquaponics Tank do you Need for Oscar Fish?

Adult Oscar fish grow to be quite large by aquarium standards – 12 inches or more in length! Therefore, you need an extra-large tank to house a mated pair or small group of Oscars for use in aquaponics. Up to 150-gallons is needed, depending on how many fish you keep, as Oscars are active and need plenty of space. The more room they have, the less aggressive and territorial they’ll be in captivity.

How to Setup an Aquaponics Tank with Oscar Fish?

To setup an aquaponics tank with Oscar fish, start with a 100+ gallon tank. A mated pair of Oscars with a small group of silver dollar fish is a good combination or you could go with a species-only aquarium and have 4 or 5 Oscars. Ensure the water conditions are conducive – temperature of 75- to 80-degrees F; pH ranging between 6 and 8; hardness level of 12 and 15 dH.

Purchase some devil’s ivy plants and place them in grow beds with lava rock at the top of the fish tank. You’ll need two canister filters. The filters will attach on either side of the tank to create flow through the grow beds. The wastewater from the fish tank is then pumped into the grow beds whereby the roots of the plants absorb the nitrates before returning the water (filtered and clean) into the fish tank.

*For more information on setting up an aquaponics tank at home, including the equipment and supplies needed as well as the various design options to choose from, please refer to my article entitled: What is an Aquaponics Tank?

lightly colored Oscar fish

What are the Pros and Cons of Using Oscar Fish in an Aquaponics Tank?

In terms of using Oscar fish in aquaponics, there are both advantages and disadvantages to such a setup. These include the following:


  • Oscars are big fish and produce a lot of excrement – the more detritus in the wastewater, the better able it is to nourish the plants which, in turn, do a better job of filtering out toxins
  • Oscars don’t typically eat live plants so they’re of no threat to the greenery or its roots in the aquaponics system
  • Oscars are active, colorful, and a joy to observe in captivity
  • Oscars are thought to be the most intelligent fish in the aquarium trade


  • Oscars are big fish and need an extra-large tank which requires more time and effort to maintain
  • For an aquaponics system to work, you’ll need more than just a mated pair of Oscars – a small group of Oscars or a mated pair of Oscars with some compatible tankmates is required
  • Oscars are more expensive to purchase – anywhere from $10 to $20 per fish
  • Oscars require plenty of food to sustain them and must be fed at least twice a day

How Many Oscar Fish can be Kept Together in an Aquaponics Tank?

Oscar fish are best kept in mated pairs or small groups of 5. It’s not recommended to house 3 Oscars in the same tank as two will likely pair up and bully the odd one out! For aquaponics, keeping 5 fish is better since a pair likely won’t produce enough organic matter to benefit the plants. If you only have enough space to house a pair, consider adding other compatible aquatic creatures to the tank.

What Tankmates are Best for an Aquaponics Tank with Oscar Fish?

Oscar fish are active and aggressive by nature. Therefore, they require tankmates of similar size and temperament. Peaceful, schooling fish that are fast and can outswim Oscars are also a good option. For aquaponics, consider adding a group of 4 silver dollars, if you have the space – an extra-large, 150-gallon tank, for example. Don’t add small invertebrates like shrimp or crab to the tank as they’ll get eaten.

What Types of Plants are Best for an Aquaponic Tank with Oscar Fish?

The best plant for an aquaponic tank with Oscar fish is pothos or devil’s ivy. It’s a hardy, tropical vine that can thrive in humid, low-light conditions. Best of all, Oscars won’t disturb the roots so it can grow lush and full. The healthier the plant, the better able it is to remove carbon dioxide and add oxygen to the tank. All you need is lava rock for drainage – the nutrient-rich aquaculture water will do the rest.

What Type of Food is Best for Oscars in an Aquaponics Tank?

Feeding omnivorous Oscar fish a diet of both plant- and meat-based foods is important for the purposes of aquaponics. This’ll ensure they stay healthy and produce nutrient-rich waste needed to nourish the plants. High-quality cichlid flakes and pellets are recommended as well as ‘treats’ like live or frozen bloodworms and brine shrimp as well as boiled peas, blanched spinach, and lettuce leaves.

planted fish tank

Final Thoughts

To sum-up, Oscar fish can be used for aquaponics, so long as they’re kept in mated pairs or small groups in an extra-large aquarium. Using compatible plants that thrive in the same environmental conditions as Oscars is also required. Keeping the tank clean and feeding Oscars nutrient-rich food will help sustain the ecological balance needed for both fish and plants to thrive in an aquaculture environment.

I trust this article has answered your questions pertaining to Oscar fish and aquaponics. Thanks for reading and good luck with your aquarist endeavors!

Recommended Posts

Best Tank Size for Oscar Fish (55, 65, 75, 90 or 125 Gallons?)

Best Tankmates for Oscar Fish

What to Feed Oscar Fish?

How Fast Do Oscar Fish Grow?

Do Oscar Fish Eat their Babies?