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Clownfish are the most popular marine fish in the world, and seeing a pair nestle into an anemone is one of the highlights of reef keeping. Clownfish are hardy and well suited to beginners. Anemones are a bigger commitment. This guide explains how to keep both successfully, and when to wait.
Clownfish care at a glance
| Need | Recommendation |
|---|---|
| Tank size | From 75 litres for a pair of ocellaris or percula |
| Temperature | 24–26°C |
| Salinity | 1.024–1.026 SG (33–35 ppt) |
| Diet | Omnivore: quality pellets plus frozen mysis and brine shrimp |
| Temperament | Peaceful with other species; territorial with other clownfish |
| Lifespan | 10 years or more; some live over 20 |
Choosing clownfish
- Ocellaris and percula are the classic orange and white "Nemo" clownfish. They're the most peaceful and the best choice for most tanks.
- Designer morphs such as Black Ice, Snowflake and Platinum are varieties of ocellaris and percula, with the same care needs.
- Maroon clownfish grow larger and become aggressive. Keep them in bigger tanks without other clownfish.
Choose captive-bred clownfish where you can. They adapt to aquarium life and prepared foods far more easily than wild fish.
Keep clownfish as a single fish or a pair. All clownfish are born male; in a pair, the larger fish becomes the female. Adding a third clownfish usually leads to bullying.
The right tank
A pair of ocellaris clownfish can live happily in a well-established 75 litre tank. If you want an anemone too, go bigger: around 100–200 litres gives more stable water and room for the anemone to move. All-in-one systems make a good start, such as the Fluval Sea EVO 52L for clownfish alone, or the UNS Dual All-In-One 60A and TMC First Wave for clownfish with corals. Browse our marine beginner aquariums and marine nano tanks.
Do clownfish need an anemone?
No. Captive-bred clownfish live perfectly well without an anemone, and many never meet one. They often adopt a soft coral, a hammer coral or even a powerhead as a substitute. An anemone is a lovely addition, but it's optional.
When to add an anemone
Anemones are sensitive to unstable water. Wait until your tank has been running for at least six months, with stable parameters, before adding one. Before you buy, check that:
- Salinity, temperature, alkalinity, calcium and magnesium are stable from week to week.
- Ammonia and nitrite read zero, and nitrate and phosphate are measurable but low.
- Your lighting is strong enough (see below).
- Every pump intake is covered, because anemones wander and can be shredded in an unguarded pump. Many powerheads have guards or flow kits, such as the Charterhouse 3D Vortech MP10 Flow Kit. See our wavemaker guards.
Our guides to reef aquarium chemistry and what to test for explain the key parameters.
Choosing a host anemone
The bubble tip anemone (Entacmaea quadricolor) is by far the best choice for aquariums. It's the hardiest host anemone, it's accepted by ocellaris, percula and maroon clownfish, and aquacultured specimens adapt well. Colour forms such as the Rose Bubble Tip Anemone are especially popular. See our current anemone selection.
Carpet and long tentacle anemones are much harder to keep and better left to experienced reef keepers.
Lighting and flow for anemones
Anemones rely on light for most of their energy. A bubble tip anemone needs moderate to strong reef lighting, similar to many LPS and SPS corals. Spotlight-style LEDs such as the Kessil A80 suit nano tanks, while the Kessil A360XE covers larger systems. Our reef lighting guide explains PAR and coverage; browse marine and reef lighting.
Give anemones moderate, varied flow. Too little and they struggle to shed waste; too much and they'll keep moving. An anemone that wanders constantly is telling you something isn't right, often light or flow.
Adding an anemone
- Acclimatise it slowly over 30–60 minutes, as you would a fish.
- Place it on rock in a sheltered spot, near where you'd like it to settle. It will choose its own place, often a crevice where its foot is protected.
- Leave it alone for a few days. Don't move it once it has attached; damaging the foot can be fatal.
- Introduce clownfish after the anemone has settled. Hosting can happen within hours or take months.
Feeding clownfish and anemones
Feed clownfish once or twice a day with a good marine pellet such as Hikari Marine A, plus frozen foods such as Gamma Mysis or Ocean Nutrition Mysis. Browse marine diets.
Anemones benefit from a small piece of meaty food once or twice a week, such as mysis or chopped prawn, about the size of the anemone's mouth. A target feeder such as the TMC Reef Coral Feeder makes this easy. Clownfish often "feed" their anemone themselves, carrying food to it.
Common problems
- Anemone keeps moving: check light, flow and water stability. Some movement after introduction is normal.
- Anemone has lost colour (bleaching): often a sign of too little light, or a sudden lighting change. Correct the cause gradually.
- Clownfish won't host: captive-bred fish can take a long time. Be patient; never force the fish into the anemone.
- Clownfish has white spots: could be marine white spot or brooklynella. See our white spot guide, and always quarantine new fish.
For a full shopping list, read A Beginner Reefkeeper's Shopping List. If you'd like advice on which anemone suits your tank, our team is happy to help.
