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Are Collonista Snails Reef Safe?

Managing an aquarium is often about finding and maintaining balance, and this involves looking at all of the creatures in your tank and weighing up how they are interacting.

You need to know which species are compatible with each other, which are destructive, and which are beneficial to the overall environment of the aquarium – and that means looking at everything, not just the fish. Even inhabitants as small as snails will require your attention.

Collonista snails are small even on the scale of snails, and often only reach around a quarter of an inch in size, so it’s easy to forget about them or dismiss them.

However, they are still an important part of your aquarium’s ecosystem and you should not ignore their presence, especially if they are growing in numbers.

This kind of snail is an algal feeder and can spread through your tank very quickly – which can be alarming if you are not familiar with them.

Usually, they will be introduced to the tank because they have hitchhiked on another addition, such as a larger snail, a clam, or un-quarantined decorations.

In general, they are a peaceful and unproblematic addition to an aquarium, and may even prove beneficial in eating nuisance algae.

Are Collonista Snails Reef Safe?

Yes, collonista snails are considered reef safe and they will not do any harm to the reefs in your aquarium as they do not attack or eat coral.

Many people categorize them as beneficial grazers, and they will usually help to boost the health of your tank, because they will feed on problematic algae and keep the tank clear.

They will eat algae before it has a chance to form properly, so even if you aren’t seeing much clouding in the water, the snails are probably still providing a benefit.

These snails do not cause any issues for a reef, although some people find that they do not look very appealing, especially if the numbers climb; they can get a little “out of control” in the tank.

Overall, however, they will not do any harm even if the numbers are high, and they will continue to serve a purpose as long as there is algae in the tank.

Some snails may be damaging to reefs, such as the flamingo tongue, olive snails, murex snails, and crown conchs; many of these prey on the herbivorous snails (such as collonistas) which are needed to keep down the algae and maintain the health of your reef.

Herbivorous snails should not cause any issues, so collonistas are reef safe and indeed beneficial.

How Can You Manage The Population Of Your Collonista Snails?

You should not need to manage the population of your collonista snails; although they can increase in numbers alarmingly quickly, it is best to allow this if it happens.

The population of snails will only grow to the limit of its food source, so if you have a lot of snails, that means you also have a lot of algae, which they will take care of for you.

If you try to control the population of snails, you will probably find that the algae quickly gets out of hand, and this is a significantly worse problem, even if you find large numbers of snails aesthetically unappealing.

It is best to let your snail numbers self-regulate; if the food supply goes down, the snails will hatch fewer babies, and the population will shrink again, but if it has grown, it is because there is a lot of food.

Trying to remove the snails will often expose you to bigger issues, because the algae will get out of control quickly if there are not enough herbivores to consume it.

Many aquariums are about finding a natural balance, and diversity is a good thing, but a glut of one kind of food will result in a temporary explosion of that food’s predator – in this case, a glut of algae will result in an explosion of collonista snails. Do not be concerned if this occurs; it will balance out, and there will only be as many snails as there is algae to support them. 

Do Any Fish Eat Collonista Snails?

Yes, if you really want to get rid of the snails in your tank, you can buy certain predatory fish that will very quickly get consume them – many carnivorous fish love collonista snails.

Lunar wrasse, peppermint shrimps, halichoeres wrasse, pink streaked wrasse, sixline wrasse, pufferfish, triggerfish, yoyo loach, striped Raphael catfish, clown loach, and bala sharks will all devour snails of various types, and may help to solve a snail population problem.

However, you should assess the viability of the tank for adding new inhabitants and make sure that whatever species you choose will fit in with the conditions you have.

Make sure that there are no conflicts between the tank’s current inhabitants and the new one, and that the temperature and conditions are suitable for the fish you want to add – as well as checking that you have enough space for a new inhabitant.

Many (but by no means all) of the fish that eat snails will also eat smaller fish that they find, which could be a problem.

It is also important to be aware that a fish that preys on snails will likely wipe out the population entirely, rather than just controlling the numbers.

If you just want to reduce the population, consider tackling the algal food source, or gifting or selling some of the snails to other hobbyists for their displays.


A collonista snail is often considered a major asset in a tank, as this species will keep on top of algal growth and ensure that your tank is clean and healthy. These snails can increase in numbers quite dramatically, which sometimes causes concern or frustration, but overall, they are beneficial and getting rid of them will cause an explosion of algae. If you are worried about the numbers of snails, give them some time to balance out and address anything that may be causing algae, rather than trying to get rid of the snails.