What Snails Eat Diatoms? An Aquarist’s Guide

What Snails Eat Diatoms

What Snails Eat Diatoms? An Aquarist’s Guide

Every aquarist has encountered diatoms – those brownish, slippery films that sometimes grace our tank walls and ornaments. And while they might be an unsightly nuisance to us, did you know some snails consider them a gourmet meal? That’s right, snails eat diatoms – but which snails?

Snails that eat diatoms include Mexican Turbo Snails, Astraea, Trochus, Nerite, and Cerith. Their appetite for diatoms makes them valuable to aquariums and reef tanks, helping to keep the unsightly brown algae growth in check. Maintaining optimal water parameters can also discourage diatom growth.

This article delves deeper into the fascinating world of snails that feast on diatoms, helping to keep reef tanks and aquariums sparkling clean. Get ready to discover the efficient and diverse snail species that wage war against diatoms and transform these tanks into vibrant aquatic wonderlands.

Pertinent Aspects of Aquariums: The Nitrogen Cycle and Cycling a Fish Tank

It’s only natural to feel eager to stock your new aquarium with fish as soon as it’s set up. However, this tempting impulse must be resisted at all costs, as stocking fish in a new aquarium will result in their demise within a week.

Losing all your fish within such a short time can be heart-wrenching, particularly for new aquarists or tank hobbyists.

Related Reading: Do Snails Increase Bioload?

The crucial step is to allow the new fish tank to go through a complete nitrogen cycle, as a new aquarium or fish tank is a toxic environment for the first two months. During this time, the necessary bacteria that break down ammonia compounds into nitrite and nitrate are absent in the new aquatic environment.

Hence, the presence of ammonia compounds in the tank renders it toxic and unsuitable for any form of life. Nitrites, which would not usually harm freshwater fish, can become highly toxic in new fish tanks due to their elevated levels.

Leaving a new tank empty for approximately two months enables the completion of the nitrogen cycle, breaking down all nitrogen compounds from ammonia to nitrite and finally to nitrates.

Aquarists and tank hobbyists agree that the nitrogen cycle typically takes 4 to 6 weeks. However, the rapid changes and fluctuations during this cycle can create an ideal environment for diatoms to thrive.

Once diatoms have emerged and been identified, the next step is to explore effective methods for eliminating them.

Related Reading: Can You Cycle a Fish Tank with Snails?

How to Get Rid of Diatoms: Choosing Your Diatom Clean-Up Crew

Tank hobbyists and aquarists commonly rely on snails as efficient tank cleaners or part of the “clean-up crew.” Regardless of the name given, these snails bring a promise of cleanliness and sparkle to water environments.

Rather than debating what to call these critters, the critical question is which snail species is best suited for a specific tank environment. Each tank is unique, depending on the aquarist’s chosen stock, and different types of stock require different cleaning needs.

Important: Only introduce the clean-up crew into the fish tank after completing the nitrogen cycle.

Several snail species are renowned for their cleaning abilities, making them excellent clean-up crew members.

These species include:

  • Mexican Turbo Snails
  • Astraea
  • Trochus
  • Nerite
  • Cerith
  • Conch snails
  • Nassarius snails
  • Otocinclus catfish
  • Amano shrimp
  • Margarita snails

Related Reading: Can You Use ParaGuard With Snails?

Trochus Snails: What Makes Them Great Diatom Eaters?

Native to the Indo-Pacific region, Trochus snails have found their way into aquariums worldwide as humans have brought them out of the wild for conservation and breeding purposes.

Highly favored by tank hobbyists, Trochus snails are renowned for their voracious appetite and ability to consume substantial amounts of diatoms.

These versatile snails have a wide dietary range, including:

  • Filamentous algae
  • Green algae
  • Slime algae
  • Cyanobacteria

This makes Trochus snails ideal tank cleaners as they effectively eliminate diatoms, which cause brownness and give the aquarium an unsightly appearance.

Moreover, Trochus snails can coexist with fish in the tank since they clean up any leftover food, contributing to the overall cleanliness of the ecosystem.

Key Considerations for Trochus Snails:

  • The recommended population of Trochus snails is five per gallon of system volume.
  • The number of Trochus snails required in a fish tank depends on the level of algal growth.
  • Increasing the number of Trochus snails accelerates the clean-up process.
  • Once they have finished consuming diatoms, Trochus snails can be provided with algae wafers introduced into the tank at night.

I recommend the Hikari Usa Inc AHK21328 Tropical Algae Wafer 8.8-Ounce for Trochus snails (link to Amazon). It is a highly preferred choice due to its high vegetable content and inclusion of pure cultured spirulina. This top-selling pleco diet is rich in stabilized vitamin C, promoting stress reduction and disease resistance while keeping the water clear.

Astraea Snails: Their Love for Hair and Film Diatoms

Although found in various parts of the world, Astraea snails are originally native to the Caribbean. While they may resemble Trochus snails in appearance, the two have distinct differences.

For instance, when an algal-covered rock causes them to slip, Trochus snails can flip their bodies. In contrast, Astraea snails will remain face-up.

Nonetheless, Astraea snails are an excellent choice for a clean-up crew, mainly due to their strong affinity for hair and film algae.

They play a valuable role in keeping aquariums and reef tanks free from these types of diatoms, contributing to a cleaner and more visually appealing aquatic environment.

Cerith Snails: Their Love for Sand Beds

When it comes to choosing cleaners for an indoor aquarium, Cerith snails offer significant advantages. These snails are known for their impressive cleaning abilities.

In their natural environment, Cerith snails diligently clean waste and decaying matter near sand beds. In fish tanks, they focus on removing diatom deposits from the bottom edges of algae clinging to the glass walls.

In addition to their cleaning prowess, Cerith snails are also considered visually appealing, adding an extra aesthetic value to any fish tank. Their presence can enhance the overall beauty of the aquatic environment.

Mexican Turbo Snails: Their Love for Film and Hair Algae

Another highly recommended species for a reef tank clean-up crew is the Mexican Turbo snail. These snails are known for their voracious appetite, capable of cleaning up a small tank within a day or two.

However, their value as part of a cleaning crew goes beyond speed. Mexican Turbo snails excel at eliminating stubborn forms of algae, such as film and hair algae, that adhere firmly to glass surfaces.

Considering their impressive capabilities and body size, roughly equivalent to a golf ball, one Mexican Turbo snail is typically sufficient for a 5-10 gallon (19-38 liters) water tank.

For larger tanks exceeding 10 gallons (38 liters), 2-3 snails are generally considered adequate (source: Tidal Gardens).

Nerite Snails: The Small-Tank Species

Nerite snails are naturally found in both the Caribbean and Pacific regions. However, they have become widely available in controlled environments thanks to human intervention. They are highly sought-after as part of a cleaning crew for aquariums, being popular among aquarists, particularly those with small tanks.

What sets Nerite snails apart is their ability to clean diatoms that cling to acrylic or glass panels in the aquarium. Some species also eat diatoms growing on rocks, adding to their cleaning capabilities.

However, it’s important to note a cautionary aspect regarding these snails. When introducing Nerite Snails to the fish tank, it is crucial to ensure they do not end up upside down.

They cannot flip themselves over, and if left facing up, they can easily die. Proper attention and care should be given to ensure their well-being in the tank.


Keeping an aquarium is not for those seeking relaxation but rather for those willing to actively engage in the survival of the species housed in the tanks. This responsibility begins from the moment the aquarium is set up.

You should allow the tank to rest for approximately 4-6 weeks to facilitate the completion of the nitrogen cycle. To maintain a sparkling clean tank, aquarists and hobbyists can rely on Mexican Turbo snails, Nerite Snails, Cerith Snails, Astraea Snails, and Trochus snails, which have a consistent appetite for diatoms and diligently keep the tanks clean each day.  

Frequently Asked Questions

Do Nassarius snails eat diatom?

Nassarius snails are known to consume diatoms. They are scavengers that feed on various organic matter, including diatoms, detritus, and leftover food particles. Their feeding behavior helps to maintain water quality in saltwater aquariums.

What will eat brown diatoms?

Otocinclus catfish, amano shrimp, and nerite snails effectively consume brown diatoms and certain other types of algae. However, introducing them to your aquarium at the appropriate time is critical, as they may also consume live plants if added too early.

Do conch snails eat diatoms?

Conch snails are voracious eaters of algae, diatoms, fish waste, substrate bacteria, and decaying organic matter in aquariums. However, due to their rapid feeding pace, they may quickly exhaust their available food sources. Providing additional sustenance such as algae wafers, sinking pellets, or other suitable foods is vital to ensure their continued nutrition and well-being in the aquarium.

Will Margarita snails eat diatoms?

Margarita snails are known to eat diatoms. Gut analysis studies have indicated that diatoms are a significant part of their diet. They consume both macroscopic algae and detrital elements but primarily feed on diatoms.

How do I reduce diatoms in my tank?

To reduce diatoms in your tank, consider reducing the lighting duration and intensity, as excessive light can promote their growth. Regularly clean the tank and perform water changes to remove excess nutrients that diatoms thrive on. Introduce algae-eating species like certain snails or otocinclus catfish, which can help control diatom populations.



  • Paul Odoteh

    Paul Odoteh is an established writer and editor with nearly 10 years of experience in writing and editing. He holds a bachelor's degree in IT and has written for numerous publications and individuals. Currently, Odoteh is dedicated to expanding his blog, SnailPedia.com, which was inspired by his passion for owning an aquarium.

    https://www.snailpedia.com pdoteh@gmail.com Odoteh Paul

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