Snails · Pomacea diffusa

Mystery snail care guide

Also called: Spike-topped apple snail, Golden mystery snail, Blue mystery snail, Ivory mystery snail, Magenta mystery snail, Pomacea bridgesii

Mystery snails are colourful apple snails, about 2 inches (5 cm) across, that scavenge leftovers and dead plant matter. They are peaceful and fun to watch, but they need hard water for a healthy shell, a tight lid and a plan for their egg clutches.

Mystery snails need a tank of at least 10 gallons (38 L), and water at 21–26°C (70–79°F) with a pH of 7.2–8. They grow to about 5 cm (2 in) and are peaceful.

Plan a tank with mystery snailsSee all tank mates

Mystery snail quick facts

Scientific namePomacea diffusa
FamilyAmpullariidae
OriginAmazon basin, South America (the colour forms in shops are captive-bred)
Adult size5 cm (2 in)
Minimum tank10 gallons (38 L)
Temperature21–26°C (70–79°F)
pH7.2–8
Hardness (GH)8–18 dGH
Group sizeCan live alone
TemperamentPeaceful
Swims atAll levels
DietOmnivore
Care levelEasy
Lifespan1–2 years
Safe with plants?Mostly (nibbles soft plants)
  • Known jumper: keep a tight-fitting lid.

Tank setup

Give one snail at least 10 gallons (38 L), and add about 2 gallons for each extra snail in a lightly stocked tank. They breathe air at the surface through a snorkel-like tube, so they need easy access to the top. Keep a tight lid on, since they can crawl out and dry up. A waterline close to the lid also leaves females less room to lay eggs.

How many mystery snails in a tank?

The smallest common tank that suits mystery snails is a 10 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.

TankMystery snails (alone)
3 gallonToo small
5 gallonToo small
10 gallonUp to 16
15 gallonUp to 24
20 gallonUp to 32
20 gallon longUp to 32
29 gallonUp to 47
40 gallonUp to 65
55 gallonUp to 89
75 gallonUp to 121
125 gallonUp to 203

What you need for mystery snails

Sized for a 10 gallon tank, the smallest common size that suits mystery snails. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.

Tank and equipment

Food and extras for mystery snails

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Water parameters

Keep them at 21–26 °C (70–79 °F), pH 7.2–8.0 and at least 8 dGH. Soft or acidic water thins and pits the shell, so add crushed coral or a mineral supplement if your water is soft. Cooler water within this range slows them down and often means a longer life. Avoid copper medicines and salt treatments.

Best tank mates for mystery snails

These popular species share mystery snails' water needs and temperament. See the full list of 106 good matches.

Avoid keeping mystery snails with

  • Oscar: Oscar eats snails, including mystery snails.
  • Assassin snail: Assassin snail eats snails, including mystery snails.
  • Clown loach: Clown loach eats snails, including mystery snails.
  • Discus: They need different temperatures: Mystery snail 21–26°C (70–79°F), discus 28–30°C (82–86°F).
  • Dojo loach: Dojo loach eats snails, including mystery snails.
  • Electric yellow cichlid: Electric yellow cichlid eats snails, including mystery snails.

Feeding

They eat leftover fish food, biofilm, soft algae and dead plant leaves. Give them a sinking food a few times a week, such as algae wafers, shrimp pellets or blanched spinach or zucchini, and include calcium-rich foods for shell growth. Remove uneaten vegetables within about 12 hours.

Behavior

Peaceful and active, often gliding over the glass or floating up to the surface. They don't attack fish, shrimp or other snails. They mostly leave healthy plants alone but may eat duckweed and soft or melting leaves, especially if underfed. Avoid puffers, snail-eating loaches, large cichlids and fish that nip their feelers, such as some bettas.

Breeding

Each snail is male or female, so you need both to get babies. Females climb out of the water, often at night, and lay a pink, raspberry-like clutch above the waterline, usually under the lid. The eggs hatch in one to four weeks depending on warmth. To prevent babies, remove clutches as soon as you see them.

Tips from experienced keepers

  • Buy snails under 1 inch (2.5 cm). Young snails live longer with you and aren't laying eggs yet.
  • A snail sitting still with its trapdoor shut is often just resting. Check for a foul smell before deciding it's dead.
  • Never release mystery snails or tank water into ponds or streams. Apple snails are invasive in many warm regions.
  • Add crushed coral or cuttlebone if your water is soft and shells look thin or pitted.
  • Remove egg clutches from the lid if you don't want dozens of baby snails.

Frequently asked questions

Do mystery snails eat live plants?

Healthy plants are mostly safe. They prefer leftovers and dead leaves, but they may eat duckweed and soft or melting leaves, especially if they are underfed.

Why is my mystery snail floating?

Usually it has trapped air in its lung to drift or rise to the surface, which is normal for a day or so. If it floats for days and smells bad, it has likely died.

Can a mystery snail live alone?

Yes. They don't need company, and keeping just one is the simplest way to avoid eggs and babies.

Sources

We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.