The viridis (Chromis viridis) is a popular reef aquarium fish reaching 3.5 in (9 cm) in the home aquarium. Originating from the Indo-Pacific region, it is rated as easy difficulty and is generally considered reef safe. Its peaceful temperament makes it suitable for community reef setups when proper care guidelines are followed.
Quick facts
| Scientific name | Chromis viridis |
| Max size | 3.5 in (9 cm) |
| Min tank size | 30 gal (115 L) |
| Temperament | Peaceful |
| Diet | Omnivore |
| Reef safe | Yes |
| Care level | Easy |
| Origin | Indo-Pacific |
Overview
The following sections detail exactly how to keep this species thriving in a saltwater reef environment.
Tank requirements
Provide a minimum tank size of 30 gal (115 L) with ample live rock for grazing, hiding, and territory. Maintain standard reef parameters: temperature 75–80 °F, pH 8.0–8.4, salinity 1.024–1.026, alkalinity 8–11 dKH. This species is peaceful enough to add at any point in the stocking order. Moderate flow and lighting that suits your coral mix work well.
Water parameters
Maintain standard reef aquarium parameters for long-term health:
- Temperature: 75–80 °F (24–27 °C)
- pH: 8.0–8.4
- Salinity: 1.024–1.026 sg
- Alkalinity: 8–11 dKH
- Ammonia / Nitrite: 0 ppm
- Nitrate: < 20 ppm (lower is better for a reef)
Stability is more important than hitting a specific number. Avoid sudden swings in any parameter.
Diet and feeding
Feed a omnivore diet consisting of high-quality marine pellets, frozen Mysis shrimp, and occasional algae sheets. Feed 1–2 times daily in small amounts consumed within two minutes. Vary the diet to ensure complete nutrition and vibrant coloration.
Behavior and compatibility
This species has a peaceful temperament and coexists well with most reef-safe community fish including clownfish, gobies, and cardinalfish. Fully reef safe with corals, clams, and invertebrates.
Breeding
Breeding Chromis viridis in captivity is possible for dedicated hobbyists. Sexing can be difficult without observing spawning behavior.
Tips for success
- Quarantine for at least 2–4 weeks before adding to your display tank.
- Provide 30 gal (115 L) minimum—larger is always better for long-term health.
- Vary between frozen, pellet, and live foods for optimal nutrition.
- Maintain stable water parameters—sudden changes cause stress and disease susceptibility.
- Observe the fish eating at the store before purchasing to ensure it is feeding well.
Frequently asked questions
What tank size does a Chromis viridis need?
The minimum recommended tank size is 30 gal (115 L). This provides adequate swimming space, territory, and stable water volume. Larger tanks are always better, especially for active swimmers.
Is this fish reef safe?
Yes, this species is considered fully reef safe and will not harm corals, clams, or invertebrates.
What does this fish eat?
This is a omnivore species. Offer a mix of meaty and plant-based foods: pellets, frozen Mysis, brine shrimp, and occasional nori.
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