Clown fish care summary
|Clown fish type
|Minimum tank size
|Max size fish
Clown fish care needs
Clownfish care can be broken down into 7 simple steps/attributes:
- 10 to 30 gallons of saltwater to call home in a quiet place within your home
- Stable reef quality water with a mature biological filter that has completed the nitrogen cycle such that it converts toxic ammonia waste into less problematic nitrates
- Flowing, well-oxygenated water (achieved with pumps or air bubbles)
- Routine feedings of the right foods
- Routine light schedule to recreate sun-up and sun-down on the reef
- Some live rock or other structure to make the aquarium feel like a reef and not like the scary open ocean
- Water changes to remove waste and replenish/reinvigorate the water quality
They do not need an anemone.
Clown fish care levels explained
There are three categories of care levels: easy, moderately easy, and difficult to care for. The good news is that every clownfish on this list is considered moderately easy or easy to care for. In a Saltwater Aquarium Blog survey, 95% of 133 people were successful in keeping clownfish. That is more than 9 out of every 10 that tried keeping clownfish.
Minimum tank sizes explained
We all need space to live our lives healthily. Clown fish need the same thing. The estimated minimum tank sizes in the chart above are a bit aggressive compared with what you might see as a consensus/echo -chamber on the rest of the internet.
Other sites (including reputable ones) recommend 20-30 gallon minimums. They’re not wrong. Those are great size tanks for clown fish. Their minimum is just a little more conservative than my recommendation.
Clown fish are not open water swimmers. They tend to congregate in a relatively smaller location. If they have an anemone (they don’t need an anemone), they tend to spend their time literally right there, in the tentacles of the anemone. They don’t need a lot of volume, especially if they are the main event in the tank, and you don’t intend to keep a lot of other fish.
However, it is important to note that having a bit more open volume in a fish tank allows for a bit more of a margin for error. The smaller the tank, the less margin for error there is. So encouraging a tank size slightly above the bare minimum does have some advantages, but it isn’t a bare minimum then, is it?
Aggressiveness in clown fish explained
The categories of aggressiveness assigned to saltwater fish can be a bit confusing because there are not any clearly defined standards I’m aware of that drive the categorization. Peaceful and aggressive are relatively straightforward. Maroon clownfish are aggressive. As they get bigger, they get meaner to the fish and your hands in the tank. Yes, they might bite you. But what does semi-aggressive mean?
For the most part, you can expect most clownfish to be peaceful most of the time. Those minority of circumstances where they would not be expected to be peaceful would be if you put 3 or 4 clownfish in a tank (you could see them get along, or you could see the 1-2 that are not in the pair bullied), or if you mixed two species of clownfish or any 1 species of clownfish with damselfish or chromis.
You may also see aggressiveness start when/if the pair starts breeding. Mom and Dad are going to protect their nest, and sometimes they get a little nutty after that and protect their territory with vigor even when not protecting eggs. The larger the clownfish species, the more that seems to happen.
Finally, the longer your clownfish is in the tank, like if it outlives a generation or two of other community fish, they can sometimes be a bit territorial towards the newer additions to the tank if you add them to the tank one-by-one. But this won’t likely be all that aggressive, especially when compared with some other species that may also be in the tank reacting to the same territorial incumbent dynamic.
Hopefully, you conclude that a few of these scenarios are manageable, avoidable, or a sign that you’ve raised your clown fish so well that they are trying to raise babies. And also, hopefully, you have some more specific guidance to understand the semi-aggressive nature of some of these species.
Male/female size differences and maximum sizes
In some clownfish species, like Maroon, Ocellaris, Percula, and Skunk, the female clownfish in the pair will be significantly more significant than the male. In contrast, both genders are the same size in Clarkii clownfish. However, since every male clownfish could potentially be a female clownfish later in life, a smaller male can still potentially reach the maximum size, but not likely in the current gender role.
As a simple rule of thumb, you can expect the maximum size listed to be most applicable to a large, fully grown female, with the male being a bit or a lot smaller (most of the time).
Care required to raise clownfish
The care required to keep a clown fish in a saltwater tank is straightforward, similar to the care needed for a moderately delicate freshwater fish, and not that complicated.
For starters, clown fish are saltwater fish, so they need salt water. To make saltwater, you buy a salt mix from the pet store designed for just this purpose that has all the natural ingredients in the precisely perfect amounts to re-create ocean reef water when measured correctly. It’s as easy as making Country Time lemonade from a mix (does that product still exist?).
There are 5 important care tips, when it comes to managing the saltwater, you will keep your clownfish in.
1. Water evaporates. Salt doesn’t
Water evaporates. You know this, you’ve seen this. Salt in salt water, does not evaporate. So when your saltwater level shrinks because of evaporation (and it will shrink from evaporation), only freshwater has evaporated. The salt (and waste and everything else) stayed behind and is now more concentrated in the tank than before the evaporation. So you want to minimize the water level shrinkages by replacing evaporated water with regular freshwater.
2. Waste accumulates
Your fish tank doesn’t have a toilet, water closet, a loo, or whatever you call it. So…it’s all in there…there is no way to ‘flush’ away anything. You flush away the yucky stuff by siphoning and replacing part of the water. The advice to follow most of the time is to only replace 10-20% of the water volume on water change day.
The time to ignore that advice is if there is an emergency.
It is casually called a weekly water change or a regular water change. Only the most organized of us stick to that routine long-term. The important thing is to test your water, know if it is in good shape, and do water changes to keep it in the sweet spot. Whether you’re managing a freshwater aquarium or saltwater aquarium, this is the same thing.
3. Newly made saltwater needs to rest
Wait a day or two after mixing and setting up your fish tank the very first time, just to be safe, and always wait 2 hours or more after mixing before you use salt water when you do water changes. It may look ready, but sometimes more chemistry is happening in the bucket that could harm your fish.
Make sure the salt is fully dissolved (and, therefore, the water is stable) before using it. I like mine to sit out overnight but I have certainly rushed it more than a few times and have waited about 2 hours (there is still a little padding in my estimate there).
4. Stability and slow tweaks are better than fluctuation and constant change in pursuit of perfection (except during catastrophes)
The stability of the water chemistry is the name of the game. You want the water temperature, pH, amount of salt, and amount of waste to be consistently in the sweet spot. You also want to be a bit laid back about getting it to the right location and keeping it there more than hyper-vigilant and constantly adding or taking away things to achieve perfection so that the values keep going up and down.
5. You want to recreate tropical ocean water parameters
If you measure the salt mix correctly (it’s not hard to do, you use a measuring cup, just like baking), the water you create should be the proper pH and salinity, without any ammonia, nitrites, or nitrates in it. Here is a table listing the ideal water parameters for a clown fish aquarium:
|8.1 – 8.4
|0 parts per million (ppm)
|0 parts per million (ppm)
|Low ~ less than 40 parts per million (ppm)
Over time, nitrates will build up due to the nitrogen cycle. Ammonia and nitrites in your tank are signs of a problem with your filter. You can learn more about water parameters here.
What do clownfish eat in an aquarium?
On a reef, a clownfish will be an opportunistic eater, snagging a small meal, throughout the day, on good days, whenever the current sends it in the right direction. That is a difficult thing to recreate in a home aquarium. So the general advice is to feed them small meals 2-3 times daily.
There is nothing magical about the number. However, it’s encouraging two things…aim for more than one meal a day and try not to make it a huge meal.
Any more than that, if you were manually feeding them, it might scare you away, but I share the reef story. Hence, you understand the frequency is intended to closely replicate normal eating behaviors. Also, recognize that the ocean isn’t going to provide food like clockwork.
There are other advantages to more frequent, smaller meals, too. Small meals are more likely to be fully consumed, which means less waste, which means more minor damage to the water quality, which means happier fish and happier humans who have to do less maintenance.
If you miss a meal or an entire day, that’s no big deal if your fish is otherwise happy and healthy. If you go away for a weekend, it’s no big deal if your fish is otherwise well fed. It’s no worse than a hard day at the reef.
If you take a week-long vacation, your fish will also be okay some percentage of the time. Let’s say, the majority of the time, the majority of the fish will be OK. That’s a pretty tough week on the reef, but very likely, your fish is overfed and has some fat reserves to hang in there.
If you leave your tank for more than a week without someone caring for it, you’re asking for trouble. If you live in the home with the tank and don’t feed your fish for a week, you’re starving the poor fish.
If you cannot do 2-3 feedings a day, one feeding will be acceptable. Your fish will adapt as long as you meet the minimum nutritional needs in that feeding.
A quick tip about feeding and vacations
In the last few days leading up to a time when I know I’ll be separated from my fish tank, I fatten up my fish with more feedings whenever possible, to counteract the calorie loss from the fasting I’m about to impose during my travel.
What do you feed clownfish?
Clown fish are very good at eating. Most clownfish were born and raised in an aquarium setting, and the companies that raise them to get them used to eating the usual foods. Here are the options you have:
- Live foods: brine shrimp, mysis shrimp, blackworms
- Frozen foods: mysis shrimp, brine shrimp, and all sorts of other frozen foods
- Pellets: small, dry, nutrient-dense pelleted foods; some sink, some float
- Flakes: dry, thin layers of food that float on the surface
Most clown fish will eagerly eat any of the above, with the greatest zeal in this order: live, frozen, pellets, flakes (although your fish may have a different palate).
Clown fish, like humans, are omnivores, which means that they eat all sorts of things and likely need different foods to be max-healthy. That doesn’t mean they want to share your creme brulee, but some variety in their fish foods is likely to be more nutritionally complete and, therefore better for your clown fish.
Maintenance required in clown fish care
Fish tanks are great for doing two things–holding water (with fish in the water) and growing algae. They may actually be better at growing algae than holding water, so performing maintenance to prevent algae or remove algae will be part of your new hobby. There is no way to avoid it other than to ignore it, which will eventually be pretty unappealing to look at.
Daily maintenance to care for a clown fish
Cleaning the inside of the glass for clown fish care
Daily, you will want to clean your aquarium glass to wipe away the algae film that grew there since the last time you wiped it. The easiest and dryest way is to use one of the expensive magnet cleaners. I don’t know why they are so expensive. But, they work.
If you miss a day, your tank will be fine, but the job gets harder each day you miss. It’s potentially the difference between a 1-minute quick wipe daily and a 15-30 minute scrub once a week.
You will probably also want to wipe down the outside glass (the part in your room) to wipe away drips and keep it looking amazing. Just use a small amount of freshwater and a microfiber towel. No chemicals.
Test the water daily for optimal clown fish care
It is also best to verify the temperature, salinity, pH, Ammonia, and Nitrates daily until you get totally bored because you know exactly what the result is going to say. You have a bit of a sixth sense because you can tell when the water quality has changed–because you’ve been watching and testing.
It is best to record these in a spreadsheet or a Reef Journal.
You will need these items for proper clown fish care:
- Thermometer to measure temperature
- Test strips and/or a test kit to measure pH, Ammonia, Nitrates
- Hydrometer to measure specific gravity, which is used to estimate/measure the salt concentration (salinity)
You will also try feeding your fish 2-3 times daily.
Turn on the lights daily (or set them on a timer)
Your clownfish will need light. If you only have clownfish and no corals or anemones, just about any old light will do. You want the lights on for 8-12 hours each day and off for the remaining 12-16 hours. I include this as a maintenance step, but if you automate it with a smart plug or a timer, you set it once and never have to do that ‘task’ again.
Weekly maintenance for clown fish care
Weekly, you will want to do the following, in support of your clown fish care:
- Replace any water that evaporated with dechlorinated fresh water. If the amount of evaporation is significant, you can and probably should replace the evaporation more often than weekly. Still, if you have a lid on the tank, I guess approximately weekly will be fine.
- Wipe away any salt crystals you see build up around the lid, corners of the tank, or anywhere water drips and then evaporates
- Scrape away algae on the glass, if you skipped a few days
- Perform a partial water change of ~10% by using a gravel vacuum/siphon to suck out about 10% of the water and replace it with aged clean saltwater. Try to remove any debris, detritus, or problem algae buildup you observe
Once you get through the first several months and the early algae blooms (diatoms, dinoflagellates, cyanobacteria, hair algae, etc.) and you notice your water parameters are consistent/good, with no algae, you can scale back on the water changes–but early on, it helps you to stay on top of it because you’re constantly removing excess nutrients and are physically removing algae along with the cleanup.
How are clown fish care needs different from a freshwater fish
Caring for a pair of clown fish in a saltwater tank without an anemone or corals is actually somewhat similar to caring for freshwater fish. The primary care needs are to maintain stable, high water quality, a day/night cycle with the lights, regular feedings, and water changes to remove waste.
The main difference is the salt. In clown fish care, you need to buy a special salt mix, measure it and mix it in the correct ratio. You also need to replace evaporated water with dechlorinated freshwater to maintain the proper salt ratio. Beyond that, care is substantially similar to freshwater.
Adding invertebrates to the tank, like anemones or corals, does make the care significantly more complicated and is the subject of other articles on this site.
Equipment needed for clown fish care
Here is the equipment needed to care for a clown fish in a saltwater tank:
- An aquarium (10 or 30-gallon minimum size)
- Lid for the aquarium
- A heater
- Aquarium lights
- Smart plug
- Powerhead pump or air pump with airline
- Gravel vacuum/siphon
- Glass cleaning magnet
Some all-in-one systems come equipped with some of these items, but if not, you will need to purchase them separately.
Here are the supplies needed for clown fish care in a saltwater tank:
- Saltwater aquarium salt mix (buy the bucket size, you will need and use lots of buckets in this hobby)
- Test strips or kit (ammonia, nitrates, nitrites, pH)
- Variety of frozen and dry saltwater fish foods
- Regular towels and rags for cleaning up drips and salt creep
- Microfiber towel for making the aquarium glass shine without chemicals
Aquascape and decorations needed
For clown fish care in a saltwater tank, you will need the following decorations to aquascape:
- Live rock
- Live sand
- Any aquarium decorations you want: mangrove roots, fake rocks, Star Wars theme decorations, etc.
Best location to care for clown fish
The best tank location for clown fish care is somewhere you get to enjoy it, which is also out of the way from vibrations (like foot traffic from humans or machines running, etc.). Fish are food, not friends, to many creatures that enjoy eating fish. So most fish are wary of fast motions and vibrations in the water because those things also tend to be associated with
If you are planning a larger tank, you have the added considerations of weight and the floor structure supporting the weight that will influence things, but if your tank is near one of the minimum sizes, you shouldn’t have a problem with the weight of that tank in support of your clown fish care.
Clownfish tank mates
The good news is that most clown fish species are relatively peaceful community fish, meaning there are many great tank mates. Other saltwater fish have very similar requirements as clown fish care.
In a survey of Saltwater Aquarium Blog Community members, the four most common clownfish tank mates were:
Check out this other article for the rest of the best clown fish tank mates.
Establishing a pair of clown fish
An interesting aspect of clownfish biology is that they are born with male and female reproductive organs. The technical term for what they exhibit is called sequential hermaphrodism, or you might say that clownfish are sequential hermaphrodites.
Those are some big words, but the concepts are not that complicated to understand. Calling them hermaphrodites means that they have both male and female organs. The term sequential tells us that they are not ‘both’ male and female at the same time, but rather that they are either male or female with the potential to change sequentially from the first gender into the second.
In the case of clownfish, that gender transition occurs only in one direction, from male to female. This specific type of sequential hermaphrodism is called protandry, or protandrous hermaphrodism.
Now, with those fancy schmancy terms out of the way, let’s break down what that means practically speaking.
All juvenile clownfish become males first.
Therefore, on the reef, if you were to encounter a small group of clownfish, what you would observe is that the largest, most dominant fish in the group would be the one and only female. The second largest fish would be the dominant, breeding male. Any other tagalongs are likely juvenile males.
Then, if the female is lost, the breeding male would change gender to become the breeding female, and one of the juvenile males would become the breeding male. It doesn’t have to go that way, it is decided amongst the clowns based on the pecking order and dominance, but that tends to be the way it goes.
There also is no turning back, either. Once female, always female.
As you can imagine, that would have created a completely different storyline for the movie Finding Nemo, as Marlin (Nemo’s dad) became the next Mother (after Nemo’s Mom was eaten by the barracuda). Then Nemo would have stepped into Marlin’s role as Father of the nest.
Not sure why Pixar didn’t go with that storyline instead.
Symbiosis with anemones
One aspect of clown fish biology that makes them so interesting to watch is their symbiosis with anemones. Anemones are generally fish-eating predators, but clown fish have evolved to safely live among the tentacles of a host anemone.
Few things in the world look as comfortable and cozy as a clown fish snuggled into their host anemone. It is very natural for most of us to want to re-create that symbiotic relationship in our tanks, but I caution against it. Anemones are challenging to keep alive. They are primarily wild-caught, and slow growing, which means the individual you see in the store might be quite old and won’t be replaced on the reef any time soon.
Meanwhile, they will likely die in your tank, which is a big bummer.
Anemones also tend to move around your tank, stinging everything in their path (which is bad), and they also tend to climb up and jam themselves into the pump and drain inflows and outflows, causing floods (after stinging everything in their path there).
Finally, clownfish don’t always take to the anemone, which is one of the ultimate letdowns.
They are not impossible to care for. They are gorgeous creatures. If you still think you gotta have it, the best option to start with is a Bubble Tip Anemone. They are often available as aquacultured (grown in captivity) specimens, they are potentially the hardiest and host the majority of popular clownfish species, but again, are not required for clown fish care.
The most popular clown fish types to care for in a saltwater tank
The six most popular clown fish types are:
- Ocellaris clownfish
- Maroon clownfish
- True Percula clownfish
- Tomato clownfish
- Cinnamon clownfish
- Clarkii clownfish
What to read next
There is a lot more to learn about clown fish care. Check out these other great, related articles:
- Ocellaris clownfish
- Snowflake clownfish(a designer type)
- Picasso clownfish (a designer type)
- Clownfish breeding journal
- Maroon clownfish
- Tomato clownfish
- Do clownfish eat their eggs?
- Best clownfish and anemone pairings
- Bubble tip anemones
Michael, Scott W. Marine Fishes: 500+ Essential-to-Know Aquarium Species. TFH Publications. Neptune City, NJ: 2001.
Saltwater Aquarium Blog Survey Data, June 2022.
Ulrich III, Albert B. The New Saltwater Aquarium Guide. Saltwater Aquarium Blog Publications. 2014.
Wilkerson, Joyce D. Clownfishes: A Guide to Their Captive Care, Breeding & Natural History. T.F.H Publications. 2001. Neptune City, NJ