The Ultimate Oscar Fish Care Guide (Diet, Tank Conditions, Breeding)

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Oscar Fish Care

The Oscar Fish is an incredibly popular tropical freshwater fish that hails from the Amazon basin of South America. Their popularity is largely due to their intelligence levels, their playful behavior and their beautiful colourings.

Oscar Fish (also known as Velvet Cichlids) are not the easiest fish to care for, so we only recommend them to aquarists who have a bit of experience under their belts. Some Cichlids can become aggressive and the Oscar Fish is no exception so it’s recommended that they are kept in a tank of their own.

With that being said, aggression is not an Oscars default behaviour and outbursts are rare so feel free to take that recommendation with a pinch of salt.

Oscars grow astonishingly fast, so it’s important that you understand what you are getting yourself into when you pick them up from the pet store or a Cichlid breeder. Oscar fish babies are as small as any other tropical fish when they are young (1 to 2 inches) but under the right conditions, they can grow at a rate of 1 inch per month, to a fully-grown size of around 10 – 12 inches.

Oscar Fish Care 101: Tank Requirements

Red Oscar Fish Tank Conditions

Due to their sheer size, it’s important that you have more than enough tank for the Oscar fish to grow into and thrive in. Anything smaller than 55 gallon per fish will be a struggle and will put unnecessary stress on the fish.

Oscars are notoriously messy fish and require a lot more maintenance than most other species. Oscars produce a lot of waste so frequent water changes are a given necessity, but the smaller the tank that you house them in, the more frequently you will have to clean them and check the water parameters.

Oscar Fish enjoy living in pairs or small groups. We would recommend keeping at least 2, or even 5 if you have the space. Keeping three isn’t always a good idea as two of the fish could bond and dismiss the other one.

Oscars are sensitive to changes in water parameters and they are also susceptible to common tropical fish diseases such as Ich, Dropsy, Fin Rot and Tail Rot. We will discuss the most common Oscar fish diseases later in this guide, but for now, just remember that clean water is absolutely essential to the health of your Oscars.

The perfect temperature for Oscar Fish is between 75 and 80 degrees Fahranheit (23 – 27 Celcius) and they prefer a pH balance of between 6 and 8. Oscars can tolerate a wide range of water hardness levels but we would recommend keeping it around 12dH – 15dH.

Oscars are very sensitive to changes in water temperature as well as increases in ammonia levels. Because of this, we would recommend a good quality water filtration system as well as an aquarium heater with a built-in thermometer. Not knowing the precise temperature and letting the ammonia levels spike is a surefire way to cause stress in the fish, leading to a loss of colour, a lack of appetite and a general unhappiness.

Make sure you have a good quality water test kit on hand to regularly test the water parameters. The one we use religiously that has never let us down is the API Freshwater Test Kit

In terms of the tank setup and decorations, I wouldn’t worry too much about it. Oscars love to rearrange their environment themselves so just add a few plants, rocks and ornaments and let them get to work playing interior designer.

What Do Oscar Fish Eat?

Now that you know what the ideal tank should look like for your Oscar Fish, it’s time to look at what you should be feeding them.

Oscars are very liberal when it comes to their diet. They will eat almost anything that you put inside their tank. Because of this and also because of their size, it’s crucial that you understand their nutritional needs fully and it’s up to you to make sure that they are met. A balanced diet is always recommended.

Oscar Fish Diet

In their natural habitat, Oscars will feed on a lot of small insects and crustaceans. Occasionally you can offer your Oscars live foods as well as feeder fish such as Goldfish or Rosy Red Minnows. It’s worth noting however that feeder fish are not nutritionally adequate and usually contain too much fat if fed in large quantities.

To be on the safe side and to make sure that your Oscars are getting fed everything that they need, we would recommend feeding an equal amount of processed flake or pellet foods and live foods such as insects, shrimps and worms.

Oscars also require a higher level of Vitamin C and plant matter which they would usually get offhand from the prey that they would eat in the wild. Algae supplements such as Hikari Tropical Wafers are a great way to add this fibrous plant matter into their diet without causing any bloating problems.

Just like their owners, Oscars love variety in their diets and will appreciate a consistent circulation of different types of foods. Here is a “shopping list” of suitable foods that we would recommend…

  • Brine Shrimp
  • Bloodworm
  • Krill
  • Cichlid Pellets/Flakes/Wafers
  • Frozen Peas


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