🐠 Free tool · straight from our care sheets

Compare two species

Torn between two fish, corals or inverts — or want to see how they really stack up? Pick any two and compare what matters for keeping them well, side by side. Every value comes from our fact-checked care sheets, so it can never contradict the full guide.

Ocellaris Clownfish Percula Clownfish
KindFishFish
DifficultyBeginnerBeginner
GroupClownfishClownfish
Adult sizeAbout 3–3.5 in (7.6–9 cm); up to ~4 in (10 cm). Females are noticeably larger.About 3 in (7–8 cm), occasionally to ~4 in (10 cm). Females larger.
Minimum tank~15–20 gallons for one or a bonded pair; 30+ gallons for a reef (sources differ — BRS lists 15 gal, TFH recommends 30+). Bigger, more stable water is more forgiving for a new keeper.~15–20 gallons for one or a bonded pair; 30+ for a reef (BRS lists 15 gal). Stable water matters more than a big number.
Temperature75–82°F (24–28°C).75–82°F (24–28°C).
pH8.1–8.4.8.1–8.4.
Specific gravity1.020–1.025.1.020–1.025.
Other paramsNitrate under ~20 ppm; stable salinity matters more than a perfect number.Nitrate under ~20 ppm; steady salinity beats a perfect one-off reading.
DietOmnivore — a quality marine pellet or flake as the staple, plus frozen mysis and brine shrimp. Small amounts 2–3 times a day; remove uneaten food.Omnivore — a quality marine pellet or flake, plus frozen mysis and brine shrimp; small amounts 2–3 times a day.
TemperamentHardy and generally peaceful in a community — but territorial toward other clownfish, including its own kind.Hardy and generally peaceful — a touch bolder and more territorial than the ocellaris, especially around a chosen host.
Reef-safeYes — safe with soft, LPS and SPS corals and with inverts. One reason it's the classic first reef fish.Yes — safe with soft, LPS and SPS corals and with inverts.
LifespanA long-term commitment — 10+ years, and 15+ with excellent, stable care.A long-term fish — 10+ years, essentially the same as its near-twin, the ocellaris.
OriginIndo-Pacific — eastern Indian Ocean through Australasia (Thailand, Malaysia, Singapore, Indonesia, the Philippines, Taiwan, NW Australia), north to southern Japan.
Choosing, not cohabiting. This tool helps you pick between species. To check whether two fish can actually share a tank, use thefish compatibility checker andstocking calculator.

Quick answers

How do I choose between two saltwater species?

Compare what decides whether you can keep them well, not just looks: difficulty, adult size, minimum tank, water parameters and temperament for fish; light, flow and placement for corals. This tool lays those side by side straight from our fact-checked care sheets, so the comparison can never contradict the full guide.

Can I keep these two species together?

This tool is for CHOOSING between species, not confirming they can share a tank. Whether two fish can live together depends on temperament, size and tank space - use the fish compatibility checker and stocking calculator for that. Use this tool to compare species you are deciding between.

Can I compare a fish and a coral?

Yes. The tool shows the fields each one has, so a fish shows tank and temperament while a coral shows light, flow and placement, side by side. It is handy when planning a mixed reef and weighing up what a new addition needs.

Are the numbers in this tool reliable?

Yes - they come straight from our species care sheets, each fact-checked against authoritative marine-aquarist and aquatic-vet sources, so the comparison always matches the full care sheet. It is honest guidance to help you choose, not a substitute for reading the full sheet.

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