Updated: Nov 14, 2021
There a dozens of species of nerite snails in the family Neritidae. Most of them are marine, many are brackish and only a few can live comfortably in freshwater. Amongst those are the Neritina natalensis (spotted nerite), and the Neritina turrita (zebra nerite). These two species are the most commonly sold in the aquarium trade as freshwater nerite snails. However, if you have a tank with low pH and soft water, your nerite won't thrive and may not survive.
A short video of a recent addition to my tank.
Most gastropods need calcium in the water so they can grow their shells. Therefore softer water, water with a low calcium and magnesium content, are not ideal for most snails and nerites are no exception. N. natalensis and N. turrita begin their lives in brackish water. They emerge from eggs laid by a singular female, fertilized by a singular male. They can then live out their days in the brackish mangrove swamps of Africa they are native to, or migrate to more fresh water, growing up to one inch. If they end up in fresher waters, the pH must still be above 7, the general hardness above 4 dKH, and the temperature between 74 and 78 degrees Fahrenheit for them to thrive. To reproduce, they will return to brackish water. This is why you will rarely see them reproduce in the home freshwater aquarium.
If you provide the correct environment for a freshwater nerite snail and choose to add one to your aquarium, you won't be disappointed in its' ravenous appetite for algae. They consume all different kinds of nuisance algae, without eating plants, and will clean up your rocks, decorations and glass. They prefer an established planted aquarium with plenty to eat.