The Oscar

7th Jun 2023

The Oscar

The Grand Oscar Fish: A Comprehensive Guide for Novice Aquarists

This charismatic creature is a favourite among aquarists, thanks to its striking appearance and interactive behaviour. So, let's get you ready to welcome an Oscar into your home aquarium.

What are Oscar Fish?

Oscar fish (Astronotus ocellatus) are native to South America and are popular among aquarists worldwide. They belong to the cichlid family and are renowned for their intelligence, vibrant colours, and the unique personality they exhibit. Oscars can reach up to 30-40 cm in length, hence they demand spacious living conditions.

Housing Your Oscar Fish

As Oscars grow quite large, the first rule is to provide them with ample space. A single Oscar fish requires a minimum of 200 litres, but if you plan on having more than one, aim for a tank of at least 400 litres. They are strong swimmers, so a tank with a large horizontal area is preferable.

When it comes to substrate, both gravel and sand work well, and decor can be added. However, be aware that Oscars are notorious for rearranging their tank decorations.

Recommended Water Parameters

Oscar fish prefer warmer water, so aim to keep your tank’s temperature between 23-28°C. The pH should be slightly acidic to neutral, ideally between 6.0-7.5. Oscars are not overly sensitive to water hardness, but generally, a dH of 5-20 is suitable.

Like any other fish, Oscars thrive in clean water. Regular water changes and a good filtration system are crucial to keep your Oscar healthy.

Feeding Your Oscar Fish

Oscars are primarily carnivorous and love a varied diet. A combination of high-quality carnivore pellets and live or frozen food such as bloodworms, brine shrimp, and krill works well. They are also known to enjoy the occasional treat of fresh fruits and vegetables. 

Choosing Tank Mates

Oscars are a semi-aggressive species and can grow quite large, so choosing tank mates requires thought. Other large South American cichlids, big catfish, large Plecostomus, and large silver dollar fish.

However, it's crucial to keep a close eye on their interactions, especially at feeding times, to ensure there are no serious conflicts.


The Oscar fish can be a fantastic addition to your aquarium, offering not just a vibrant spectacle but also an engaging pet. Remember, these fish require dedicated care, ample space, and a good diet to flourish.

As always, successful fishkeeping comes from understanding and meeting your fish's specific needs. So, equip yourself with the right knowledge, and you'll enjoy every moment with your Oscar. Good luck!