organism
Nerite snail vs mystery snail
Which snail for a planted community tank?
Short answer
Nerites for algae control — they eat hard green spot algae that almost nothing else touches, and cannot breed in fresh water. Mystery snails for a larger, more visible animal that eats detritus and leaves plants alone.
Side by side
| Dimension | Nerite snail | Mystery snail | Favours |
|---|---|---|---|
| Adult size | 2–3 cm | 4–6 cm | — |
| Algae eating | Excellent, including green spot | Modest | Nerite snail |
| Breeds in fresh water | No — larvae need brackish water | Yes, above the waterline | Nerite snail |
| Lays visible eggs | Yes — hard white capsules that never hatch | Yes — pink clutches above the waterline | Neither |
| Eats healthy plants | No | No | Neither |
| Needs an air gap at the surface | No | Yes — it breathes air | Nerite snail |
| Climbs out of the tank | Frequently | Occasionally | Mystery snail |
| Bioload | Low | Moderate | Nerite snail |
Which to choose
Nerite snail
Choose nerites for algae control in a tank you do not want overrun with snails.
Mystery snail
Choose mystery snails for a larger, more interesting animal — and leave an air gap above the waterline.
One caveat
Both need hard, alkaline water with adequate calcium. In soft acidic water their shells pit and erode, and the damage does not repair.