What tank size does a Japanese Trapdoor Snail need?

A Japanese Trapdoor Snail needs an aquarium of at least 40 litres (10.6 US gallons) with a footprint at least 45 cm (17.7 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Japanese Trapdoor Snail need?

Japanese Trapdoor Snail does best at 2–28 °C (35.6–82.4 °F), pH 6.5–8.5 and a general hardness of 6–20 °dGH.

Is the Japanese Trapdoor Snail suitable for beginners?

Yes — Japanese Trapdoor Snail is one of the easier species to keep and forgives typical first-tank mistakes, as long as the aquarium is cycled and maintained.

Species library

Japanese Trapdoor Snail

Cipangopaludina japonica

Viviparidae

InvertsDifficulty: ●●○○○Data: well-established

📷 Oregon Department of Fish & Wildlife · CC BY-SA 4.0 · resized · iNaturalist

Japanese Trapdoor Snail — Cipangopaludina japonica — 📷 Oregon Department of Fish & Wildlife · CC BY-SA 4.0 · resized · iNaturalist

About

The Japanese trapdoor snail is a large, cold-hardy freshwater snail from East Asia, prized as a peaceful algae grazer for ponds and unheated aquariums. It carries a rounded, olive-brown shell sealed by a horny operculum — the 'trapdoor' — which it pulls shut for protection. Fully aquatic and undemanding, it tolerates everything from near-freezing pond water to tropical warmth, slowly cleaning up algae and detritus without harming healthy plants.

Care

Excellent for coldwater ponds and unheated tanks, yet equally content in tropical setups. Provide hard, alkaline water with ample calcium for shell health and avoid copper entirely. Plant-safe, fully aquatic and a very slow livebearer that will not overrun a tank.

Diet

Grazing omnivore feeding on soft algae, biofilm and detritus. Offer algae wafers, blanched vegetables and a calcium source such as cuttlebone; it ignores healthy plants when regularly fed.

Tankmate compatibility

Gets along with (35)

Possible with care (188)

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Avoid (48)

Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.

Telling males from females

There is no reliable way to sex this species by eye. That is the honest answer, not a gap in our data.

All the methods, with diagrams

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Frequently asked questions

What tank size does a Japanese Trapdoor Snail need?: A Japanese Trapdoor Snail needs an aquarium of at least 40 litres (10.6 US gallons) with a footprint at least 45 cm (17.7 in) long — for this species, swimming length matters as much as raw volume.
What water parameters does a Japanese Trapdoor Snail need?: Japanese Trapdoor Snail does best at 2–28 °C (35.6–82.4 °F), pH 6.5–8.5 and a general hardness of 6–20 °dGH.
Is the Japanese Trapdoor Snail suitable for beginners?: Yes — Japanese Trapdoor Snail is one of the easier species to keep and forgives typical first-tank mistakes, as long as the aquarium is cycled and maintained.

Sources

Water & tank

Temperature2–28°C

Optimal temp.18–24°C

pH6.5–8.5

Hardness (GH)6–20°d

Carbonate (KH)4–12°d

Adult size5 cm

Min. volume≥ 40 L

Min. tank length≥ 45 cm

Swimming zoneBottom

TemperamentPeaceful

Water typeFreshwater

FlowLow

Lifespan~5 yrs

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