Clownfish Tank Setup – Guide for Beginners

Disclosure: I may earn a commission when you purchase through my affiliate links. As an Amazon Associate I earn from qualifying purchases. – read more

You may have heard that clownfish are hardy and adaptable and that they make for great beginner fish.

This is true, but with some notable mentions. While these fish are more adaptable than others, they still require personalized care to thrive.

Today, we will touch upon everything clownfish-related, from the tank size to the layout, water parameters, diet, and everything else you need to learn about them.

If you’re a novice clownfish enthusiast, keep reading!

Choosing Tank Size for Clownfish

Naturally, the tank size is the first step to overcome. Several things you should know here:

  • Clownfish are poor swimmers – It’s not that clownfish don’t know how to swim, it’s just that they’re using a lot of energy doing so. This is due to their swinging body motions that are only fit for short swimming sessions. This low mobility is the reason why clownfish rely on anemones to survive in the wild. We’ve mentioned this point to highlight why clownfish don’t need too much space, to begin with. Around 20 gallons for a pair of 4-inch clownfish should suffice in most cases.
  • Can’t have too many clownfish – You don’t need extra room to accommodate multiple clownfish because this isn’t how this species rolls. Clownfish are pair-based fish that won’t tolerate the presence of other clownfish, whether it’s their own breed or another. So, you should only keep a pair at most. If you want to have multiple clownfish, you need to increase the tank size considerably and assume territorial violence will become the norm.
  • Need room for tank equipment and decorations – Always account for the space necessary to accommodate the various decorations that make up the clownfish’s habitat. These fish are reef animals that like a diverse ecosystem. Caves, rocks, reef structures, and other decorations are very useful in this sense. You also need room for the filtration system and any other equipment pieces that you may use.
  • Consider future community upgrades – Many people opt for community setups, given the clownfish’s social behavior and easy-going attitude. These fish can adapt to any community setting, provided their tankmates are equally peaceful and sociable. Get a larger tank if you plan on upgrading to a community setup down the line. This will save you from having to purchase a different aquarium when the time comes. Plus, your clownfish won’t mind the extra space until their tankmates arrive.

As you can tell, the ideal tank size for your clownfish varies based on your goals. You generally need at least 20 gallons to accommodate your typical Nemo pair but may require more depending on the situation.

Some clownfish species, like the maroon or the Clarkii, require more space, given that they can reach 6 and 7 inches, respectively.

In their case, a 50-55-gallon+ setup would be more appropriate.

Setting Up the Clownfish Tank

Now that you have decided on the right tank, you now have the following to consider:

Placement of the Tank

You want to place the tank in a well-aerated room with stable temperatures. Clownfish don’t like temperature drops, given that their ideal temperature range is 74-79 F.

Light levels don’t matter too much, so long as they are not too bright and you have a good day-night cycle in place.

Also, place the tank in a less circulated room to prevent the fish from getting stressed. Clownfish can get rattled by sudden movements outside their tank.

This is due to the fish being rather less apt at facing any potential threats due to its reduced swimming capabilities.

Filtration System

The filtration system is essential for any clownfish setup. This is due to the filter’s role in the ecosystem’s hygiene and the water movement it produces.

Clownfish live in ecosystems with moderate water movement, which aids in better breathing and an overall cleaner environment.

The filter will also suck in floating particles, detritus, algae and plant matter, and food leftovers. This will prevent the formation of ammonia and nitrites, to, which clownfish are quite sensitive.

Aquarium Equipment

The aquarium equipment necessary for a clownfish tank can vary depending on the clownfish species and whether you have a single-species or a community setup.

Overall, you may need the following:

  • Heater – Keeps the temperatures stable and allows for constant monitoring and better temperature control.
  • Filter – Cleans the habitat, boosts oxygenation, and offers the necessary water movement that clownfish require to thrive.
  • Water conditioner – This is necessary in case your fish require some extra water nutrients that would promote healthy mucus production. Water conditioners also have antibacterial properties, keeping your fish calmer and healthier over the years.
  • Live rocks – These aren’t vital for your clownfish tank but will make for a great addition nonetheless. Live rocks house a variety of organisms that your clownfish will happily consume to supplement their diet.
  • Water tester kit – You absolutely need a water tester kit to verify water quality occasionally and prevent dangerous fluctuations. The tester kit is useful for detecting ammonia, nitrite, or chlorine contamination, as well as highlighting other heavy metals or chemicals that may affect your aquarium’s life.
  • A net – This is necessary to remove fish, eggs, or floating matter like algae or dead plants whenever necessary.
  • Refractometer – This is a necessary piece of equipment, given that refractometers measure water salinity. This makes the tool critical for any marine ecosystem.
  • Protein skimmer – A useful tool designed to remove food residues, waste, and nitrates. It also prevents dangerous nitrate buildup due to dead organic matter in the water.

All these tools and equipment are necessary to preserve your clownfish’s ecosystem in top shape for years to come.

Substrate & Decorations

In terms of substrate, go for sand, crushed coral, or aragonite. These are necessary to buffer the water pH and provide your clownfish with a natural-looking ecosystem.

In terms of decorations, take diversity as a starting point. Clownfish live in diverse ecosystems with plenty of rocks and other hiding areas available.

They don’t use to hide a lot but require a varied layout to remain comfortable and at peace.

Cycling the Tank

You should never introduce your clownfish to an uncycled ecosystem. These fish are particularly sensitive to ammonia and nitrites, so you should always cycle the tank first.

The fishless tank cycle is pretty straightforward:

  • Prepare the tank – You add the substrate, add the water, and add the decorations.
  • Have an ammonia source – Ammonia is the byproduct of fish activity, generally speaking. Since you have no fish in the tank, you require an alternate source. Simply get pure ammonia, no colorants, additives, or any other chemicals that may sabotage the process. Get a water tester kit ready, and add several drops of ammonia to reach the desired concentration. You’re looking for 2-3 mg/L (2-3 ppm) on average. Don’t let ammonia go above 5 ppm, or the nitrifying bacteria won’t be able to transform it into nitrites.
  • Perform regular water changes – You now have to supervise the cycling process and test the tank water regularly. Perform a partial water change whenever ammonia levels get close to 5 ppm.
  • Manage nitrites – Nitrites should become ‘visible’ in the water 2-3 days later, which is a sign that nitrifying bacteria have formed. Once that happens, you only need to add half the amount of ammonia you were using in the beginning. Again, the goal is to keep ammonia levels between 2 and 3 ppm. The same concentration applies to nitrites. Perform a partial water change whenever each chemical approaches its acceptable thresholds.
  • Cycle completion – You can consider the cycle complete if, upon adding the regular dose of ammonia, it all disappears literally overnight and no traces of nitrites are visible. When that happens, measure the amount of nitrates present. The presence of nitrates in concentrations of up to 20 ppm is a sign that the denitrifying bacteria are now present. At this point, the cycle is complete, and you can add the fish.

Just make sure you control the amount of nitrates. These aren’t as toxic as ammonia or nitrites, but they’re still dangerous in concentrations above 20 ppm.

This is why partial water changes are necessary for all aquatic ecosystems, with a frequency that varies depending on each case.

You can also use an activated carbon filter to clear out any potential contaminants along the way.

Monitor Water Parameters

This is a critical point because water parameters can fluctuate at times. Clownfish need stable temperatures, pH, salinity, and clean water overall.

Ignoring this will place your clownfish in a difficult spot, making them prone to health problems along the way. Swim bladder disease and marine Ich are real dangers to consider.

You should always monitor water parameters to make sure your fish are healthy and safe. Also, keep an eye on your clownfish.

They will exhibit signs of stress whenever something’s not right with their water. Early measures will prevent more extensive problems down the line.

Getting Your Clownfish

Clownfish are a popular aquarium breed, so you shouldn’t have problems finding a couple of specimens.

That being said, I advise caution when purchasing your clownfish. Clownfish are notoriously mistreated by fish shops that cannot provide them with a healthy and balanced ecosystem.

They are often poorly fed, overcrowded, and kept in subpar conditions that make them prone to health problems.

Make sure your fish is healthy and doesn’t have any genetic or physical issues that could turn into life-threatening issues later on.

I recommend getting your first clownfish pair from a more reputed seller and breeding the fish at home. This will ensure the fish’s quality and prevent any unwanted surprises.


Clownfish are hardy, peaceful, and cute marine fish that can adapt to any community life.

Pair them with some peaceful tankmates and ensure optimal living conditions, and your clownfish will honor you with your presence for years to come.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
Leave a Comment

Your email address will not be published. Required fields are marked *