How big does Guppy get?

Guppy reaches an adult standard length of 2.5–6 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.

What water does Guppy need?

22–28 °C, pH 6.8–7.8, 8–20 dGH, 4–12 dKH. At 6 °C wide it is one of the more forgiving ranges.

What is the smallest tank for Guppy?

At least 40 L, and no shorter than 50 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is a schooling fish: keep at least 3 together. Fewer than that and it hides, loses colour, and aggression has nowhere to spread.

What is Guppy like to keep?

Temperament: peaceful. Difficulty: beginner. It occupies the top and is omnivore. With plants it is "Leaves plants alone".

Can Guppy be kept with its most common tank mate?

The checker returns "Can be kept together". Guppy and Platy is a well-established pairing. Individual fish still differ; the record says "usually fine", not "guaranteed".

G-01 / 01Freshwater

Guppy孔雀鱼

Poecilia reticulata · Poeciliidae

The classic beginner livebearer: endless male tail colors and ready-made fry.

Illustration to come

G-01 / 01 · Guppy Poecilia reticulata

SpecificationsFish atlas

Name: 孔雀鱼
Scientific name: Poecilia reticulata
Family: Poeciliidae
Origin: Northern South America (Venezuela, Trinidad, northern Brazil)
Adult size: 2.5–6 cm
Temperament: Peaceful
Diet: Omnivore
Water level: Top
Level: Beginner
School size: ≥ 3
Min. tank: 40 L
Min. length: 50 cm
Plant safe: Leaves plants alone

Water requirementsFreshwater

Temp.22–28 °C

pH6.8–7.8

Hardness8–20 dGH

Alkalinity4–12 dKH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Keeping notes

1Keep two females per male at minimum; isolate a female before she drops, or the adults eat the fry.
2Prefers hard, slightly alkaline water; sudden temperature or pH swings bring on ich and fin rot.
3Omnivorous on flakes plus brine shrimp, twice a day in portions finished within two minutes.
4Safest with platies and mollies; avoid tiger barbs and angelfish that chase and nip long tails.

Check a tank mate

Jump straight to the verdict for Guppy against this one — no need to pick it again.

Frequently asked questions

How big does Guppy get?: Guppy reaches an adult standard length of 2.5–6 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.
What water does Guppy need?: 22–28 °C, pH 6.8–7.8, 8–20 dGH, 4–12 dKH. At 6 °C wide it is one of the more forgiving ranges.
What is the smallest tank for Guppy?: At least 40 L, and no shorter than 50 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is a schooling fish: keep at least 3 together. Fewer than that and it hides, loses colour, and aggression has nowhere to spread.
What is Guppy like to keep?: Temperament: peaceful. Difficulty: beginner. It occupies the top and is omnivore. With plants it is "Leaves plants alone".
Can Guppy be kept with its most common tank mate?: The checker returns "Can be kept together". Guppy and Platy is a well-established pairing. Individual fish still differ; the record says "usually fine", not "guaranteed".