Koi (Cyprinus carpio) is a intermediate-level freshwater fish that needs at least 500 gallons and 40-80°F. Koi are pond fish that grow very large. Small koi can live in aquariums only temporarily.

Care facts at a glance

Scientific nameCyprinus carpio
FamilyCyprinidae
OriginCaptive-bred
Adult size24 in
Minimum tank500 gallons
Temperature40-80°F
pH7.0-8.5
TemperamentPeaceful
Social behaviorGroups
Swim levelAll levels
DifficultyIntermediate
DietOmnivore: koi pellets, vegetables
Typical lifespan25+ years

Quick tips

  • Plan for a pond.
  • Cannot stay in small tanks.

San Diego water

Naturally suited to San Diego's hard, alkaline tap water once it is dechlorinated (the city uses chloramine, so use a conditioner that handles it). Learn the numbers in our San Diego tap water guide.

Before you buy

Make sure your tank is cycled (how to cycle a tank), check your numbers with the water testing guide, and use the compatibility guide to check tankmates. These are general ranges; individual fish and local water vary.

Find it at Pet Zone

Pet Zone Tropical Fish is a San Diego aquarium store with two locations. Stock changes daily, so call ahead if you are after a specific species or plant. Shop online at petzonesd.com.

Pet Zone Convoy

4160 Convoy St, San Diego, CA 92111
(858) 987-0309
Open daily, 10am-6pm

Aquascaping, planted tanks

Pet Zone Mid-City

4266 University Ave, San Diego, CA 92105
(619) 283-1812
Closed Monday; Tue-Fri 10:30am-6pm, Sat 11am-6pm, Sun 11am-4pm

Monster fish, koi