Do Mystery Snails Eat Algae?

I love my mystery snails – and I’ve had quite a few of them. They spend all day driving around your aquarium helping to keep things clean.

Mystery snails eat quite a few types of algae (in addition to other things). They aren’t as good of algae eaters as other species like the nerite snail or mystery snail, however, so they shouldn’t be looked at purely as a method of controlling algae in an aquarium.

Let’s discuss this in a bit more detail.

Do Mystery Snails Eat Algae?

The answer to this question is that yes – mystery snails do eat a varieties of soft algae, including both green and brown algae.

A few mystery snails aren’t going to take care of your algae problem, though. They graze on algae more than they eat it.

The types of algae that mystery snails eat include:

  • Brown Algae (Diatoms)
  • Soft Green Algae (Including the small fuzzy green stuff that grows on glass walls)

Although mystery snails can eat these types of algae, they tend to graze on what’s present on the substrate, decorations, and walls (and may not eat all of it).

They’re not particularly likely to get what’s growing on the surfaces of leaves or other hard to reach places.

Types of algae that mystery snails don’t eat include:

  • Hair algae
  • Black beard algae
  • Staghorn algae
  • Phytoplankton (Green Water)
  • Blue-Green Algae

If you have these types of algae in your aquarium, you shouldn’t expect them to eat any of them.

Not much will take care of Blue-Green Algae or Staghorn, so if those are what you have you should be prepared to clean it by hand and increase flow in your aquarium. (And change water more often.)

What Do Mystery Snails Eat?

Mystery snails mostly feed on the biofilm available on all of the surfaces of your aquarium (walls, substrate, decorations, etc) as well as dead fish, leftover food, dead plant matter, and other things that fall to the bottom.

Contrary to popular belief, they’re not so hot on eating living plants. I’ve had plants and mystery snails in my aquarium, and I’ve never seen them feeding on a healthy plant.

It seems that their main source of food is the biofilm – based on my experience – and they’ll incidentally pick up the soft green algae from the walls or the diatoms from the floor as they’re passing through.

This is why they’re not as good at clearing your aquarium of algae, because it’s not mainly what they’re going for.

Better Choices for Algae Eaters

The best algae eater is probably the nerite snail. They have problems of their own, but they are most well known for eating most types of algae and doing a fairly good job of it.

Among shrimp, the amano shrimp is the star algae eater – though YMMV on how big of a dent they will make in your algae issue.

Among fish, the rubber lip pleco and young siamese algae eaters are the best algae eaters.

Most of these options will even eat the hard types of algae that other creatures won’t get to – except plecos won’t eat hair algae. You can check my guides on things that eat hair algae and black beard algae if you’re having those problems specifically.


Mystery snails do indeed eat algae. I’ve even had a mystery snail live in an aquarium entirely off of algae and biofilm (fed him once or twice his entire life) without any other fish or fish food to feed off of. (Lived longer than average for a snail by quite a bit.)

If you’re thinking about getting a mystery snail specifically as an algae eater, however, you should probably reconsider. You’ll end up being disappointed when they don’t eat as much algae as you expect them to.