Care guide

Nerite and mystery snails with shrimp

By the Shrimp Tank Hub editorsUpdated Oct 23, 2026Research-based

Research-based, not hands-on. We haven't run controlled trials ourselves. This guide compiles hobby references, manufacturer documentation and recurring owner reports (e.g. r/shrimptank, 2024–2026). Checked October 2026. How we research

Snails are the classic clean-up crew for a shrimp tank, and nerite and mystery snails are the two most people consider first. Both are peaceful, both graze on algae and leftovers, and neither hunts shrimp. They differ a lot in size, appetite and breeding, though, and a few common shrimp-keeping habits, such as very soft water and pest treatments, can be hard on snails. This guide covers what to expect from each, and how to keep both snails and shrimp healthy in the same tank.

Quick version: yes, nerite and mystery snails are generally safe with cherry shrimp and other dwarf shrimp. They don't hunt healthy shrimp, though they will scavenge a dead one. Nerites stay small, eat mostly algae and can't breed in fresh water, but leave hard white eggs on surfaces. Mystery snails are bigger, eat more (including shrimp food), and lay egg clutches above the waterline. Both need some GH and KH for healthy shells, both need a lid, and most planaria and hydra treatments will kill them.

Do snails eat shrimp?

Nerite and mystery snails don't catch or attack healthy shrimp. Both are grazers and scavengers. Owners sometimes find a snail on a dead shrimp and assume the worst, but a snail feeding on a shrimp that has already died is cleaning up, not hunting. If you keep finding dead shrimp, the snail is very unlikely to be the cause; start with why are my shrimp dying.

The snail that is a real concern is the assassin snail. It hunts other snails and is sometimes reported to eat weak or newly molted shrimp, so many shrimp keepers leave it out, especially in breeding tanks. Our cherry shrimp tank mates guide covers other options, from fish to other shrimp.

Nerite vs mystery snails at a glance

	Nerite snails	Mystery snails (Pomacea diffusa)
Adult size (roughly)	Small; often around 1 inch, horned types smaller	Larger; often around 2 inches
Main food	Algae and biofilm on glass, rocks and leaves	Algae, leftovers, sinking foods and decaying plant matter
Competes for shrimp food	A little	Yes, readily eats shrimp food
Breeding in a home tank	Eggs do not hatch in fresh water	Breeds; males and females are needed, clutches laid above the water
Eggs you will see	Hard white dots on rocks, wood and glass	A cluster of eggs above the waterline
Waste (bioload)	Low	Noticeably more
Escape risk	High; can climb out	Can climb out; needs a lid with an air gap
Best for	Algae control in small shrimp tanks	Larger tanks where extra waste is not a problem

Sizes and habits vary by species and individual, so treat these as rough hobby guidelines.

Nerite snails with shrimp

Nerites are popular with shrimp keepers because they are small, eat algae steadily and don't overrun a tank. Several kinds are sold, including zebra, tiger, olive and horned nerites.

No population boom. Nerites need brackish water for their young to develop, so the eggs they lay in a freshwater tank don't hatch.
The white eggs. Females still lay small, hard white eggs on rocks, wood, equipment and glass. They are harmless but hard to scrape off, and some keepers dislike the look on dark hardscape.
Escapes. Nerites are known for climbing out of tanks, so keep a lid on and cover any gaps around tubing.
Enough food. A small, very clean tank may not grow enough algae for a nerite. If the glass and rocks are spotless, offer an algae wafer or blanched vegetable now and then.

Mystery snails with shrimp

Mystery snails are colorful and active, and many people enjoy watching them. In a shrimp tank, plan for three things:

Bigger appetite. Mystery snails eat shrimp pellets, wafers and blanched vegetables as readily as shrimp do, and they produce more waste. Feed so the shrimp still get their share, for example by spreading food or using a feeding dish, and remove leftovers. See best shrimp food.
Egg clutches above the water. Mystery snails have separate sexes, and females lay clutches of eggs above the waterline, often on the lid or glass. That is why they need a lid with a little air space. If you don't want more snails, remove clutches before they hatch.
Bioload. In a nano tank, one mystery snail adds noticeable waste. Keep up with water changes and don't overfeed.

Water hardness and shell health

Snails build their shells from minerals in the water, much as shrimp use calcium and magnesium to harden each new shell after a molt. Neocaridina water, with moderate GH and some KH, usually suits both. Very soft, acidic water is harder on snails: owners commonly report thin, pitted or cracked shells in tanks with very low GH and KH. That is worth knowing for Caridina tanks on active soil, which run soft and acidic on purpose; snails may not do as well there long term.

If shells look worn, check GH and KH first. Our GH and KH explained guide covers the numbers. Avoid making big changes to water hardness to suit a snail, because sudden shifts are a bigger risk to shrimp than a reading that is slightly off.

Treatments and products that kill snails

Planaria and hydra treatments. Most of the common shrimp-safe dewormers used against planaria and hydra are also deadly to snails. Move snails to another tank first if you can.
Copper. Copper is toxic to both shrimp and snails. Check medications, fertilizers and plant additives for copper before using them; see shrimp-safe fertilizer.
Snail-control products are made to kill snails, so keep them out of a tank with nerites or mystery snails.

Adding snails safely

Inspect and rinse. New snails can carry hitchhikers, such as tiny pest snails or eggs, on their shells. Look them over and rinse them in tank water before adding.
Acclimate slowly. Snails are sensitive to sudden changes too. The same slow approach you use for shrimp works; see drip acclimation.
Start small. One or two snails is plenty for most small shrimp tanks. Add more only if there is algae and food to support them.
Keep the lid on and cover gaps around filter and heater cords.

Never release aquarium snails. Apple snails (the family that includes the mystery snail) are invasive in parts of the US and elsewhere. The USDA allows Pomacea diffusa, the species usually sold as the mystery snail, to be moved between states without a permit, but most other apple snails are restricted, and some states, including Texas, Arizona and Nevada, regulate the whole genus according to a 2025 US Fish and Wildlife Service risk summary. Check your state's rules before buying, and give away or return unwanted snails rather than releasing them or their eggs.

What about ramshorn and bladder snails?

Ramshorn and bladder snails often arrive on plants. They are harmless to shrimp and graze on the same leftovers, but their numbers rise quickly when there is excess food. A sudden boom is a sign to feed less, not a reason to reach for a snail-killing product. They make a useful indicator in a shrimp tank for exactly that reason.

Track it

If you keep snails with shrimp, write down GH, KH and feeding along with any snail eggs or shell wear. The Water Parameter Log printable keeps it all on one page.

Frequently asked questions

Will nerite snails eat my shrimp?

No. Nerite snails graze on algae and biofilm and do not hunt shrimp. Like most snails, they may feed on a shrimp that has already died.

Can mystery snails live with cherry shrimp?

Yes, generally. Mystery snails are peaceful and do not hunt shrimp, but they eat shrimp food and add more waste, so they suit larger tanks and need careful feeding so the shrimp still get enough.

Why are there white dots on the rocks in my shrimp tank?

If you keep nerite snails, those are almost certainly nerite eggs. They do not hatch in fresh water and are harmless, but they are hard to scrape off.

Do nerite snails breed in freshwater tanks?

No. Nerite eggs need brackish water to develop, so they do not hatch in a freshwater shrimp tank, and nerites will not overrun it.

Will planaria treatment kill my snails?

Usually, yes. Most common planaria and hydra treatments that are considered shrimp-safe are deadly to snails, so move snails to another tank before treating if you can.

Why are my snail shells cracking in my shrimp tank?

Thin, pitted or cracked shells are commonly linked to very soft, acidic water with low GH and KH. Check your water hardness, and avoid sudden big changes that could stress shrimp.

Sources: USDA APHIS, Snails and Slugs; US Fish and Wildlife Service, Spike-topped Applesnail (Pomacea diffusa) Ecological Risk Screening Summary (2025). Care details are compiled from hobby references and owner reports.