Assassin Snail
Clea helena
The Assassin Snail (Clea helena) is a peaceful snail that's easy to keep. Give it a tank of at least 20 litres (5 US gallons), water held at 72-81°F, and a pH of 7-8.5.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
Various
We don't shade a region on this simplified map - your text may be Europe-only, worldwide, listed as "Various," captive-only, or outside the five areas used in the stocking calculator. That tool still scores whether your fish come from similar parts of the world.
Regional colours match the stocking calculator's origin map.
Assassin Snail Tank Setup
Keep them in at least 20 litres (5 US gallons) with steady water at 72-81°F and a pH around 7-8.5. Healthy shells depend on enough calcium and clean, stable water.
What Do Assassin Snails Eat?
They're bottom feeders, so give them sinking wafers, tablets, or frozen treats like bloodworm once the lights go down. Flakes that never reach the bottom leave them hungry even when the tank looks well-fed.
Assassin Snail Tank Mates
Sensitive to copper and some medications. The Assassin Snail is peaceful, which is the first thing to weigh up when you choose tank mates. Good matches come down to the whole stocking list working together - temperature, tank size, and temperament - not any single label. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Assassin Snails Good for Beginners?
Reasonable early choice after cycling. Buy after the tank has stable ammonia and nitrite readings, not the same weekend you fill it.
Assassin Snail - frequently asked questions
What size tank do Assassin Snails need?
Assassin Snails need a tank of at least 20 litres (5 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
What water parameters do Assassin Snails need?
Keep them at 72-81°F with a pH of 7-8.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Assassin Snails eat?
Assassin Snails are bottom feeders. Give them sinking wafers, tablets, and frozen foods that settle on the substrate, ideally after the lights go off. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Assassin Snails good for beginners?
Yes - Assassin Snails are a reasonable beginner fish once the tank is cycled and parameters are stable. Add them after ammonia and nitrite read 0 ppm, not the same day you fill the tank.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Assassin Snails
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- OscarPredator - Oscar will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
