Saltwater Fish

Green Chromis

Chromis viridis

Care guide, husbandry, breeding, disease, and sourcing intelligence on Green Chromis - written by the Fast Aquatics editorial team.

Green Chromis at a glance
Adult size: 4 inches · Min tank/pond: 30 gallons · Difficulty: beginner · Diet: omnivore · Lifespan: 8-15 years.

Green Chromis (Chromis viridis) is a popular saltwater fish in the aquarium and pond hobby. Hardy and forgiving when given proper water chemistry.

Where Green Chromis comes from

Green Chromis (Chromis viridis) is native to Indo-Pacific reef ecosystems. Wild populations distribute across coral reefs from East Africa through Indonesia, the Philippines, and into the western Pacific. Captive-bred Green Chromis is increasingly available and is the more sustainable choice when you can find it.

Green Chromis tank size and setup

Green Chromis requires a minimum of 30 gallons for healthy adults. The minimum is based on 4 inches adult size and territorial range. For Green Chromis, plan a mature reef tank with stable parameters, sand bed, live rock for cover, and reef LED if photosynthetic.

Water parameters for Green Chromis

Green Chromis requires standard reef parameters: temperature 76-80°F, specific gravity 1.025, pH 8.1-8.4, alkalinity 8-9 dKH, calcium 420-450 ppm, magnesium 1300-1400 ppm, ammonia + nitrite 0 ppm, nitrate under 10 ppm. Use a refractometer (not hydrometer) to measure salinity.

What Green Chromis eats

Green Chromis is a omnivore. Provide a varied diet of pellets, frozen foods, and supplemental greens. Feed twice daily in small portions. Browse our food guides for product recommendations.

Green Chromis tankmates and compatibility

Green Chromis is best paired with peaceful reef-tank species in similar size class. Avoid known fin-nippers and large aggressive species.

Green Chromis adult size and lifespan

Green Chromis reaches 4 inches at adulthood with a captive lifespan of 8-15 years with proper care.

Can you breed Green Chromis?

Green Chromis breeding in captivity ranges from straightforward to very difficult. Captive-bred specimens are increasingly available from sustainable aquaculture facilities.

Common Green Chromis diseases and problems

Green Chromis is susceptible to ich, velvet, marine flukes, and bacterial infections. Quarantine new Green Chromis for 4-6 weeks before adding to display.

Where to buy Green Chromis online

Green Chromis is sold at LFS, online retailers, and direct from breeders. Browse live Green Chromis from vetted Fast Aquatics vendors with carrier-tracked overnight shipping, climate-aware hold logic, and a 4-hour DOA window with photo-evidence claims.

Other species in the same category with care profiles on Fast Aquatics. Click any name for the full husbandry breakdown.

Square AnthiasTorch CoralGreen Wolf EelAdult Lawnmower BlennyReef Rock CrabMithraculus sculptusRed Brittle StarOphioderma squamosissima

Sources and references

Green Chromis taxonomy and care recommendations cross-checked against the following authoritative references and our internal vendor + breeder database.

Have a photo of Green Chromis?
Approved photos go live in 24 hours, with credit (or anonymous - your call).

More resources for Green Chromis keepers

Common diseases
Helpful calculators
Key terms

Browse the full disease database, calculator collection, aquarium glossary, or Q&A library for additional reference.

Deep-dive Q&A on Green Chromis

Answers to the questions experienced keepers ask after the basic care guide.

How long does Green Chromis take to acclimate to a new tank?

Drip acclimation over 60 to 90 minutes is the safest approach for Green Chromis. Match temperature first (15 minute float), then drip 2 to 3 drops per second from the display sump until the bag volume has tripled. Test salinity (or freshwater hardness) at the end - if it is within 0.001 SG (or 2 dGH) of the display, transfer the specimen with a net rather than pouring shipping water in.

What is the best filtration setup for Green Chromis?

Aim for biological + mechanical + chemical staging. Canister or sump-driven filtration sized for 5x to 8x display turnover per hour, mechanical floss replaced weekly, and carbon or GAC swapped every 4 to 6 weeks. Green Chromis responds well to stable nitrate (under 20 ppm) more than to any specific filter brand - stability beats peak performance.

Does Green Chromis need a protein skimmer?

For saltwater specimens, yes - a properly-sized skimmer rated for 1.5x to 2x display volume keeps dissolved organics low and reduces nuisance-algae triggers. Freshwater specimens do not need skimmers; a well-stocked plant grow-out + canister with chemical media achieves the same end. Green Chromis kept without adequate organic export tends to show stress within 90 days.

Can Green Chromis be kept in a planted tank?

Compatibility with planted tanks depends on the species behavior + water chemistry overlap. Plant-safe specimens leave foliage alone; some pick at soft-tissue plants like vallisneria or anubias. Check the species page profile + the planted-tank compatibility note before stocking Green Chromis in a high-tech CO2-injected setup with valuable cultivars.

What is the ideal lighting for Green Chromis?

For freshwater specimens with no plant requirements, a basic LED at 30 to 50 PAR at substrate is sufficient and reduces algae. For saltwater + reef specimens, target 100 to 250 PAR depending on photo-tolerance, with a sunrise/sunset ramp + a 8 to 10 hour photoperiod. Green Chromis tolerates a wider lighting band than most keepers expect; consistency matters more than peak intensity.

Does Green Chromis prefer high or low water flow?

Most aquarium species evolved in moderate flow with localized turbulence rather than uniform high flow. Aim for 20x to 40x display turnover for reef specimens, 4x to 6x for community freshwater. Green Chromis shows stress fins (clamped, frayed) when flow is mismatched - dial back if you see this within 14 days of introduction.

What temperature shift will stress Green Chromis?

Sustained drift above +/- 2 F from target is the threshold most keepers miss. Green Chromis tolerates day-night swings of 1 to 2 F without issue but a 4 F shift over 2 hours triggers ich + bacterial bloom risk. Use a controller-driven heater (not the built-in dial) and a backup thermometer at the opposite end of the tank.

What are the top 3 diseases that hit Green Chromis the most?

For freshwater fish: ich, columnaris, and fin rot are the top three; quarantine + UV sterilizer prevents the majority. For marine fish: ich (Cryptocaryon), velvet (Amyloodinium), and bacterial infections; tank-transfer method or copper QT during the 30-day acclimation cycle prevents nearly all outbreaks. For inverts + corals: tissue necrosis, parasitic isopods, and protozoan blooms.

Can Green Chromis be bred in captivity?

Captive breeding success varies enormously by species - some breed readily in community tanks (livebearers, cherry shrimp, clownfish) while others have never been captive-bred (most reef fish + most marine inverts). Check the species-specific care guide for the breeding-method note + larval-rearing protocol. Green Chromis kept in pairs or small groups often spawns even without intent if conditions are right.

What are the best tankmates to avoid for Green Chromis?

Avoid same-species rivals (especially male-male pairings for territorial species), known fin-nippers (tiger barbs, certain pufferfish), and anything that out-competes for food or out-grows the tank. Green Chromis also struggles with hyper-aggressive cichlids in freshwater and damselfish in saltwater - both will hold territory at the expense of every other tankmate.

Is Green Chromis safe to keep with cleaner shrimp or cleaner wrasses?

Most ornamental specimens accept cleaner shrimp + cleaner gobies; cleaner wrasses (Labroides) often die in captivity and are not recommended. Green Chromis kept with cleaner pairs typically benefits from parasite control + stress reduction, but verify the cleaner does not get eaten by checking the species size + temperament chart.

What is the realistic lifespan of Green Chromis with proper care?

Captive lifespan tracks closely to wild lifespan when water chemistry, diet, and tankmate stress are managed. Most aquarium fish live 5 to 12 years; long-lived species (large cichlids, pufferfish, some tangs) reach 15+ years. Green Chromis kept in a stable, properly-sized system should live within 80% to 100% of the species lifespan ceiling - early death usually traces back to chronic-stress causes (parameters, tankmates, diet) rather than disease.