How to Humanely Kill Aquarium Snails

How to Humanely Kill Aquarium Snails

Ornamental snails are unique animals to keep in your tropical freshwater aquarium. The problem is that not all snails willingly enter our tanks.

       Some species of snails can be kept without problems in aquariums; others can become a complex problem to fight. Seeing multiple spots inside the aquarium and gelatinous clumps through the glass is something every aquarist has come across or will come across at least once.

       Because they reproduce quickly and easily, these mollusks quickly infest any aquarium; because of that, they ended up receiving unique fame in the hobby, leading even experienced aquarists to fear infestations.

       Each species of freshwater snail has a different type of egg. Anyway, when you see snail eggs, you’ll know what they are.

       One of the most efficient actions to be taken in case of infestation is using strategies that lead to the death of these snails. Cause death to another living being is an issue that affects many aquarists, who are looking for a more humane way to get rid of these animals and have their aquarium balanced again.

       This article contains basic information about snail infestations in freshwater aquariums and how to dispose of them most humanely and ethically possible.

Snails in tropical freshwater aquarium

       An aquarium goes far beyond a container with only water and fish; it is a small and unique ecosystem. This closed ecosystem is fragile and shelters countless organisms that, when in balance, help keep the system stable; one of these organisms is the snail, which has its specific function within the aquarium.

       Some species have great beauty and are kept because of their ornamental character. They are easy to reproduce and resistant animals. They are considered great aquatic animals for beginners to maintain; they can even be purchased in specialized stores. Other snails appear spontaneously in our aquariums.

       The first thought that comes to the mind of the hobbyist who follows a more natural line is to let the flow of life go and let the tiny snails live their lives in peace. The problem is that the snail population can get out of control quickly, whether unwanted or ornamental.

       The functions of snails as an aquarium inhabitant are numerous; they help in algae control, in the cycling of leaves, dead fish, and leftover feed, and serving as food for fish. They are indirect water quality indicators: they reproduce more intensively when the aquarium has excess organic matter.

       The rapid and frequent reproduction is the reason for so much fear and anger on aquarium keepers. They easily multiply their population, reproducing oviparous, ovoviviparous, hermaphroditism, or even parthenogenesis.

       Among the main problems mentioned by aquarists is the unpleasant appearance caused by this population “boom,” providing a sloppy look and the attack on plants, especially those with more tender leaves such as Elodeas, Cabombas, and Foxtail.

Where do unwanted snails come from?

       Most of the time, snails are introduced to the aquarium through newly obtained plants and decorative elements; Decoration, and equipment that have been used in other aquariums and have not been adequately sanitized, will transport eggs and adult animals. We can also include substrates, filters, stones, and driftwood in this list. Even the bag of the fish you bought at a store can contain eggs.

       It’s common to find snails belonging to the Physa, Lymnaea, Melanoides, and Planorbis genera as pests in our aquariums. These species have in common that they feed on algae and eventually plants, leftover feed, and other foods, dead leaves, and even fish corpses, in addition to having a very high propagation speed.

       Anyway, it is perfectly possible to keep snails under control in the aquarium, with an acceptable population and in balance with the other inhabitants and with the system in general.

How does infestation happen?

       The infestation by snails occurs for the same reason as the explosion of algae and bacteria: Inadequate maintenance of the aquarium.

       A lack of periodic maintenance directly causes system imbalance. Management such as water renewal, removal of organic matter dispersed in the aquarium, and cleaning the substrate are techniques that must be carried out periodically to always leave the aquarium in good condition and the water in perfect quality.

       Failure to carry out the proper maintenance leaves the perfect environment for snails to dominate and increase; this also benefits algae, the main snail food.

       Keep your maintenance up to date, and your aquarium should not have infestation problems.

How to defend my tank from unwanted invaders

       Always sanitize and quarantine newly acquired ornaments and plants. Decorative objects, driftwood, rocks, and substrates can be sanitized with bleach, rinsed well, and exposed to the sun until they dry completely; this should destroy eggs, animals, and pathogens on the surface.

       In the case of plants, mosses, and other live ornaments, you can proceed with disinfection and quarantine. Disinfection can be done in different ways, using mollusk solution, permanganate baths, sanitary water, brine baths, etc. Quarantine plants for around 15 days are the ideal period for you to observe any contaminating species.

       There are several ways to disinfect; we recommend researching the different techniques, talking to specialists, and proceeding in the way that you feel most comfortable and safe.

Controlling and eliminating snails from your aquarium

       When facing a population explosion, you must be fast and accurate in combat use effective methods that do not cause problems in your aquariums or suffer the snails.

       There are several different ways to remove mollusks from our aquarium humanely. Use baits such as vegetables to attract them, then remove them from the aquarium, use proper traps, dip copper wires in water for a day or two, and chemical treatment with mollusks.

Controlling through a natural way

       It is much easier to prevent than to cure; because of this, the best alternative to take is to avoid an infestation in your aquarium. Along with the primary control method, which is the quarantine of new inhabitants and disinfection of objects, we can follow some measures that should be applied even when we do not have infestations; these techniques help avoid problems in the general health of our aquarium.

       Always feed aquarium inhabitants only the necessary amount. Leftover food will degrade the quality of the water and make food available to the mollusks, something that ends up benefiting them.

       Always carry out periodic maintenance, with the correct water change, siphoning off the substrate, and general cleaning of the tank, removing everything that should not be there, mainly algae. Ensure to remove algae, plant material, and decomposing organic material that can serve as food for the snails.

       In addition to making your aquarium highly efficient in terms of sustainability and water and environmental quality, these measures will rapidly suppress the unwanted snail population in a completely natural and human way.

       With the low availability of food and good water quality, snails will decrease their reproductive rate, resulting in population stability naturally and humanly, even with a surprising number of individuals.

       This method is, without a doubt, the easiest and most humane form of control.

Physical removal

       Physical removal is carried out in different ways and with different instruments. Each time you see a snail or eggs, remove them from the aquarium with your hands, net, tweezers, or other ways. Physical removal can also be carried out passively, using traps or baits.

       Another way to get them out of the aquarium is to use the equipment to siphon the substrate during the partial water change. Siphoning is an effective method for removing snails that usually stay on the substrate and eggs deposited there.

       Always inspect for eggs and carefully examine glass, equipment, and plant leaves; Egg masses can be found in or out of the water. These gelatinous masses are easily removed with a razor blade or scrappers.

       Repeat the procedure until the infestation subsides.

       In the passive capture method, you can use traps for this purpose. These traps usually work by adding a feed, attracting and trapping the snails. An alternative is to use vegetables or leaves to draw mollusks; when the leaf is covered with them, we remove it from the aquarium. Ideally, this method should be used just before the lights go out every day.

How to get rid of snails in a humanely way

       After removing the eggs and adults, you will end up with hundreds, not to mention thousands of snails and eggs. Because we are dealing with living creatures, we have to have certain ethics when we get rid of them.

       The most exciting thing is to separate the eggs in a secondary aquarium until they hatch; that way, you can see the animal’s life cycle complete; kids love this option.

       The young and adult snails that have been collected (or hatched) can continue their life cycle and be used as live food for fish, a very natural and pain-free outlet.

       Eggs and snails are a delight for almost all species of tropical fish, such as guppies, tetras, gouramis, and cichlids; When removing eggs and snails from the aquarium, setting them up for food is an excellent way to dispose of them. These eggs and adults can also be taken to a hobbyist or specialized store.

      Freezing is considered a humanized form of euthanasia, as it does not cause suffering or pain, in addition to being quick. By freezing, the snails can be kept to be used as food for a few weeks, or you can discard them the way you prefer.

       Other humane disposal forms involve placing the snails in a hypersaline solution or an alcoholic solution.

       Fish can always be introduced to help control these pests. Fish like Clown Loach and Pufferfish always look for treats like snails to feast on.

Chemical control

       Some hobbyists prefer to adopt chemical control, which consists of using a specialized molluscicide for the aquarium; it is considered a humanized technique, as it acts quickly, without suffering on the animals.

       To increase the efficiency of chemical control, proceed with the physical removal of the mollusks for a few days in a row. Preferably separate all the fauna in another tank, taking care not to take any eggs or snails with them, then treat the main aquarium with the mollusk component; make sure to follow the product’s package insert carefully.

       After treatment, maintain a correct maintenance routine, thus preventing reinfestation.

Unwanted methods of control

       Some methods have the principle of causing intoxication and longterm suffering in snails; everyone should avoid these techniques.

       The best known of them is the use of copper wires inside the aquarium or the slow salinization of the tank. Both methods use substances that are considered toxic to snails kill them by accumulating in the body, thus slowly killing them causing suffering and pain to the animal.

       As well as extravagantly raising the temperature of the water, the use of certain non-specialized products to finish the snails should be avoided and are not considered a humane way to get rid of them, as they lead to toxicity and suffering.


       Knowing the snail control techniques, you can adequately kill them without causing unnecessary suffering. As maintainers of our systems, we must always cherish ethics and animal welfare, both at the time of life and death.

       Scientific knowledge has evolved to provide a humanization in the form of euthanasia, so this must be considered and always carried out ethically so as not to cause suffering to the animal or the performer.

       Knowing a little about the habits and behaviors of snails helps when trying to fight or control the number of individuals.

       If your aquarium does not have these invertebrates and you want it to remain that way, remember to always quarantine and use preventive products (such as mollusks) on newly acquired plants.

       The coexistence between snails and the aquarist can be harmonious and productive; just be fully aware of the function and reason for the presence of these invertebrates in your aquarium. Just stick with your scheduled maintenance and pay attention to the teachings in this guide to keep your snail population under control.


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        Amaral RS (Org.), Thiengo SARC (Org.), Pieri OS (Org.). Surveillance and Control of Molluscs of Medical Importance: Technical Guidelines. 2nd ed. Brasília: Editora MS, 2008. 178 p.

        BRAZIL. Federal Council of Veterinary Medicine. Brazilian Guide to Good Practices in Animal Euthanasia – Concepts and Recommended Procedures. Brasília, 2013. Available at:áticas%20para%20Eutanasia.pdf.pdf

        BRAZIL. Law No. 11,794, OF October 8, 2008. Regulates item VII of § 1 of art. 225 of the Federal Constitution, establishing procedures for the scientific use of animals; repeals Law No. 6,638, of May 8, 1979; and takes other measures. Available at:

        CF, Pearce TA, Valdés A. The Mollusks: A Guide to Their Study, Collection, and Preservation. Universal-Publishers, 2006 – 445p.

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        Guimarães CT, Souza CP, Soares DM, Araújo N, Schuster LMR. Occurrence of molluscs in aquaria of ornamental fishes in Belo Horizonte, Minas Gerais, Brazil. Mem. Inst. Oswaldo Cruz, 85: 127-9, 1990.

        Guimarães MCA, Menezes RMT, Tuan R. (2016) Experimental study on reproduction of the freshwater snail Biomphalaria tenagophila (d’Orbigny, 1835), Invertebrate Reproduction & Development, 60:2, 145-151.

        Oliveira-Filho EC, Caixeta NR, Simplício NCS, Sousa SR, Aragão TP, Muniz DHF. Implications of water hardness in ecotoxicological assessments for water quality regulatory purposes: a case study with the aquatic snail Biomphalaria glabrata(Say, 1818). Brazil J. Biol. 2014 Feb; 74(1): 175-180.

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