The Ultimate Guide to Clownfish Care

Clownfish are quite easy to keep healthy and happy in a well maintained marine aquarium. In captivity, clownfish can live for over a decade and will grow to become part of the family. They are active, engaging fish and will follow you as you walk by the tank. Let our comprehensive guide walk you through everything you need to know to keep your clownfish happy and healthy for years to come!

Clownfish Care Quick View

Tank size: 8 gallon +	Water temperature: 73 – 80°F	Ammonia: 0
Nitrates: < 20 ppm	Nitrites: 0 ppm	Specific Gravity: 1.020 – 1.026
PH: 8.0 – 8.4

Setting up the Perfect Clownfish Tank

The first thing many people want to know is what size of an aquarium is needed to keep clownfish. A tank of 20 gallons or larger is ideal for Ocellaris or Percula clownfish. However, clownfish will do well in tanks that are quite small by marine aquarium standards. Nano tanks of about 8 to 10 gallons are on the small end for Ocellaris Clownfish but the fish will still do quite well in a tank that size. This Coralland 8 gallon saltwater tank is a great example of a nano tank that would work well for clownfish. In fact, many breeders will put large pairs in a 10-gallon tank or smaller for spawning. Some species, such as Maroon Clownfish, require a larger tank – 29 gallons or more.

Species	Minimum Tank Size
Ocellaris	8 gallon
Percula	8 gallon
Maroon	29 gallon
Clarkii	29 gallon
Tomato	29 gallon

Clownfish do not need a lot of room to swim like some fish do, as they will swim up and down in a relatively small area much of the time. They will be even happier in a small tank if they have a host, such as an anemone or a coral, which they can use for refuge. If you want to fast-track this symbiotic relationship, check out our guide on getting your clownfish to live in a host anemone.

The real problem with a small tank is that it requires a lot more frequent maintenance than a larger tank, as counter intuitive as that may seem. In a small tank, toxins such as ammonia and nitrates will build up faster (in relation to the water volume of the tank), resulting in poor water quality. This leads to algae growth and unhealthy tank inhabitants. With a small tank it is vitally important to have quality filtration combined with regular water changes. A protein skimmer, such as this one from AQQA, would be beneficial but is not always necessary if water changes are done on schedule.

Supply List for a Clownfish Tank

Water Parameters for Clownfish

The biggest key to a healthy clownfish tank is stability. This is why larger tanks are considered easier to maintain than smaller tanks. A higher volume of water is easier to keep stable than a smaller volume. Aim for these parameters to keep your clownfish healthy and happy:

• Temperature: 73 – 80°F
• PH: 8.0 – 8.4
• Salinity: 1.020 – 1.026 (26 – 35 ppt)
• Ammonia: 0
• Nitrites: 0
• Nitrates: < 20 ppm

A test kit, such as the API Saltwater Master Test Kit, will prove invaluable for keeping your water parameters at optimal levels.

There should be ample water movement and sufficient lighting for the tank setup. For instance, if keeping anemones or corals, you should have very strong, specialized lighting. However, fish-only tanks do not require intense lights and will be fine with standard aquarium lighting.

Best Foods for Clownfish

Types of food: pellets, flakes, frozen
How often: 1x per day
How much: only what they can eat in 3 minutes

Clownfish will happily accept a wide variety of foods. In general, any quality flake or pellet food made for carnivores or omnivores will do just fine. They will benefit from a varied diet, however. Mixing in some frozen foods or even live foods will keep your clownfish happy and healthy for years. It is best to feed at least once per day. However, depending on the size of the tank and the other inhabitants, clownfish will do just fine being fed every other day. This will cut back on maintenance issues, although your clownfish will obviously grow at a slower rate.

For pellet food, I’ve used Hikari Marine-S pellets with great success. For my breeding pairs I’ve also used Marin Ultra Marine soft clownfish pellets. They’re a little more expensive but one of the best options available for clownfish. And when it comes to flake food, Seachem’s Nutridiet Marine Flakes are my top choice.

Clownfish should be fed as much as they will eat in about 2 or 3 minutes. You want to be sure food isn’t floating around the tank for long periods of time or getting stuck in rocks and other crevices. This will lead to poor water quality and algae issues. A good cleanup crew, such as snails, crabs, and starfish, will aid in keeping any extra food from hanging around too long.

If you are hoping to breed your fish, then the feedings will need to be upped to at least three times per day with a wide variety of high-quality foods. You can read more about that in our guide on how to breed clownfish.

Clownfish Compatibility

Clownfish tend to be fairly small and relatively slow-moving. With this in mind it’s important that they aren’t placed with large carnivorous or aggressive fish such as Lionfish and Groupers. Otherwise, there are not many limits to the type of tank in which clownfish can live. They do equally well in fish only tanks, tanks with live rock, community tanks, more aggressive tanks (to a degree, of course) and full reef tanks. They do not need an anemone to live or stay healthy in captivity. Although the symbiotic relationship of an anemone hosting a clownfish is a beautiful thing, many clowns in captivity will not ever live in one, even when given the opportunity.

Here are some great tank-mates for clownfish, depending on the setup of the tank:

One thing to keep in mind is that clownfish will generally not get along with other clownfish in the tank. Ocellaris Clownfish are among the least aggressive. However, multiple clownfish (even other Ocellaris) will often fight. If you want to have multiple clowns, it is best to introduce them at the same time and make sure they have plenty of room. Alternatively, you could introduce a smaller clownfish, which is likely a male or juvenile, to a more established, somewhat larger clownfish. The larger clown will likely be aggressive to the newcomer but as long as they are not both females, the smaller fish will usually submit to the female and become the male. They will often pair up and sometimes even become mates. Before getting a tank mate you’ll want to find out if you have a male or female clownfish.

Mixing different species of clownfish is not usually recommended except in very large tanks. Different variants of the same species are completely fine in pairs though, such as a standard Ocellaris and a Snowflake Clownfish. Occasionally, even the different species will bond and sometimes eventually mate. For instance it is common for Ocellaris and Percula clownfish to pair up and live peacefully together as a pair.

Clownfish Tank Maintenance

Maintaining a clownfish tank doesn’t need to be a full-time job. The amount of time and effort it takes depends a lot on the other inhabitants. Here’s a checklist for regular tank maintenance:

• Quick equipment check (temperature, auto-top off, dosers, lights, protein skimmer, etc.) – Daily check at feeding
• Clean the glass – Weekly (more as needed)
• Test water parameters – Weekly until stable, then monthly or as needed
• Water change – Weekly to monthly, 10% – 20% depending on schedule and needs
• Check filters, pumps and clean – During water changes (as needed)

Clownfish Diseases and Problem Solving

Once established, clownfish are quite hardy. Most problems and diseases arise from improper quarantine or acclimation. Here are some of the most common issues and what you can do to help your fish.

• Breathing fast or hard: This is often a water quality issue such as ammonia. Test your parameters and prepare for a large (50%) water change. If ammonia is the issue you need to stay on top of this until the tank stabilizes.
• Stringy poop: Sometimes this will happen with new fish as they acclimate to the tank and is not an ongoing problem. However, this can also indicate an internal parasite. If the fish is still eating, medicated food is best. Look for ingredients such as Metronidazole or others indicated for internal parasites in fish. If they aren’t eating the fish should be moved to a separate hospital tank and the water medicated directly. Don’t treat the water in your display tank!
• White scales: There are three main external diseases that will affect clownfish. Brooklynella, Ich, and Velvet are three major external diseases that target marine fish like clownfish. Ich is probably the most common and looks like grains of salt on the scales. It may come and go, but if it’s in the water it is always present until treated properly. Velvet looks more “powdery” and is less common than saltwater Ich. Both can generally be treated with copper (in a hospital tank). Velvet is more urgent than Ich. Some tanks always have Ich present and strong fish can often fight off the disease (treatment is best, though). Finally, there is Brooklynella (Brook). This is highly dangerous but fortunately not very common in tank-raised fish (more common in wild-caught fish). Copper is ineffective on Brook – instead use formalin, Metronidazole, or Ruby Reef Rally. All three diseases should be treated in a hospital tank if at all possible and can be fatal if left untreated.
• Lethargy – staying in the corner or bottom of the tank: This can be difficult to diagnose. Look for other issues, such as those described above. By the time your fish is staying in one spot or not swimming normally this indicates an urgent issue. A hospital tank is the best bet and treat with something like API’s General Cure to start.  

Congrats, you’re now ready for clownfish! Our clownfish buying guide has all the information you need on where to buy clownfish and how to acclimate them to your tank safely. Overall, clownfish tanks are relatively easy to set up and maintain. Keep your fish fed well, keep the water as clean as possible, make sure they are not being harassed by their tank-mates, and your clownfish will become the tank favorite in no time at all.