Clownfish are hardy, colorful, and full of personality. They still need stable water, smart feeding, and a calm setup. This guide covers daily care, pairing, and common problems.
Tank setup and water parameters
Start with a tank that fits their behavior. Keep one clownfish in 10 gallons minimum. Keep a pair in 20 gallons or more. Choose a lid, since clowns can jump when startled.
Aim for stable reef-safe parameters. Keep temperature at 25–26°C (77–79°F). Keep salinity at 1.025 specific gravity. Keep pH at 8.1–8.4 and alkalinity at 8–10 dKH.
Control nitrogen with routine testing. Keep ammonia and nitrite at 0 ppm always. Keep nitrate under 20 ppm for fish-only tanks. For reefs, try to stay under 10 ppm.
Provide moderate flow and simple structure. Use live rock or dry rock for shelter. Add a sandy bottom if you prefer. If you want an anemone later, wait 6 months for tank maturity.
- Cycle the tank fully before adding fish. Test ammonia daily at first.
- Run a heater with a controller to prevent temperature swings.
- Do 10–15% water changes weekly in the first three months.
For step-by-step cycling help, see how to cycle a saltwater tank. For parameter targets and testing routines, use our reef water parameters guide.
Feeding, behavior, and choosing tankmates
Feed small portions two times per day. Offer pellets or flakes in the morning. Offer frozen mysis, brine, or chopped seafood at night. Remove uneaten food after two minutes.
Clownfish are omnivores and like variety. Add spirulina pellets or algae-based flakes twice per week. Soak food in vitamins once weekly. This helps color and fin health.
Expect territorial behavior near their chosen spot. They may host a coral, powerhead guard, or rock corner. This is normal. Give them a “home” area so they feel secure.
Choose tankmates that are calm and not fin nippers. Good options include gobies, blennies, and small wrasses. Avoid aggressive damsels in small tanks. Avoid large dottybacks unless the tank is spacious.
- Start with one clownfish if your tank is under 20 gallons.
- Add a second clown later to form a pair. Choose a smaller fish.
- Feed more often during pairing to reduce fighting.
If you plan a reef, check reef-safe fish ideas before you buy. It helps prevent conflicts and coral damage.
Health, quarantine, and troubleshooting
Quarantine is your best protection. Use a 10–20 gallon bare tank with a sponge filter. Match salinity and temperature to the display tank. Quarantine new clownfish for 14–30 days.
Watch for common clownfish issues. White dots can indicate marine ich. Rapid breathing can signal velvet or ammonia exposure. Stringy poop and weight loss can suggest internal parasites.
Also watch for brooklynella, often called “clownfish disease.” It can look like heavy slime and frayed fins. Fish may scratch and breathe fast. Act fast with isolation and proven treatment plans.
Many problems start with stress and swings. Keep salinity changes under 0.001 per day. Keep temperature swings under 1°F per day. Test ammonia if a fish looks “off” after a feeding.
- If a clown stops eating, check temperature and ammonia first.
- If fins fray, improve water quality and reduce aggression.
- If spots appear, move fish to quarantine before treating.
Common mistake: adding an anemone too early. Anemones need stable nutrients and light. Another mistake is overfeeding in small tanks. That often drives nitrate spikes and algae blooms.
Conclusion
Clownfish thrive with stable parameters, steady feeding, and low stress. Start with the right tank size and quarantine new arrivals. With good habits, a pair can live for many years.
Sources: Fish Disease: Diagnosis and Treatment (Noga); The Conscientious Marine Aquarist (Fenner); Captive Seawater Fishes (Tullock)
By
