Finding Your Own Nemo: Why Owning a Clownfish is Hard Work

The clownfish shot to fame after the popular computer-animated film Finding Nemo in 2003. After this, scores of children wanted a Nemo fish of their own. The irony being, of course, that the film is against keeping fish in captivity. However, the main cause for concern is that clownfish are not easy to take care of, and the decision to look after this fish should not be taken lightly. With the film’s sequel, Finding Dory, set for release in 2016, its time to get ready for another upsurge in popularity of marine animals. We take a closer look at clownfish and how hard they really are to look after.

The Clownfish

Clownfish are marine fish, which means that out of all the fish that you could choose from, they are one of the most difficult. They require warm water, as opposed to cold, and they require a salt water composition that is similar to the ocean.

They are therefore not suitable for beginners or children. If you plan on keeping clownfish, you need a tank no smaller than 30 gallons or 120 litres and the water quality should be very high and well circulated. The temperature needs to be between 24˚C - 27˚C, the salinity at 1.020 – 1.024 and the pH 8.0 – 8.4.

Clownfish will rarely get along with other clownfish in the same tank. While they are rarely aggressive, multiple clownfish will fight. If you want more than one, you should either; introduce them at the same time and make sure that they have plenty of room, or introduce a smaller clownfish to a more established clownfish. As long as they aren’t both females they will be happy together and may even mate.

The Aquarium

To keep clownfish you’ll need a filtration system, a substrate of fine aragonite, a hydrometer to measure salinity and test kits for nitrate, nitrite, ammo, ia and pH.

Feeding Clownfish

Clownfish are omnivores and will accept most foods. A varied diet will keep them happy, but they should be happy on marine flake food. Ideally, a good diet will be based around a good quality marine flake food, which is complemented by algae, frozen food and live food. Feed them 3-4 times a day if possible.

Wild Caught vs. Captive Bred

Wild caught clownfish have an extremely high mortality rate between capture and retailer, with some estimating it as high as 90%. Even if they make it to the home, they rarely survive for very long. Nemo was one of the lucky ones then that he managed to survive capture and rehoming!

The reasons for the delicate nature of wild-caught clownfish and the high mortality rate is not known for certain, but it is likely due to the stress of being pulled away from their host anemone and the rough handling during the journey.

Captive bred clownfish, on the other hand, are much hardier and relatively inexpensive. A wide range of clownfish are now bred on farms, and most retailers only stock farmed fish – but it may be worth checking as these ones are the only ones worth buying. Farmed fish are also much more preferable from an ethical point of view as well as a financial one, as the harvesting of wild caught clownfish is threatening local populations of the fish in the wild.

However, in comparison to other marine fish, they are one of the least hardy and need careful looking after.


Anemones are used by clownfish in the wild as protection from the elements, however, they can be very tricky to keep. Not all anemones will be used by all clownfish, and some can even damage or eat your clownfish.

Farmed fish, however, don’t need an anemone and as long as the tank has plenty of cover, they will be happy without one.