The Best Algae Eaters for Freshwater Aquariums
Updated: Apr 10
If you’ve got a freshwater tank set up and you’re looking to keep your natural ecosystem balanced (or as balanced as you can create) then chances are you’re in need for an algae eater or two. These little (algae) suckers are experts in clean up, but many also have quirky looks and their own personality so they’ll make a great addition to your tank in their own right, aside from their amazing snacky habbits. With you being able to take your pick from fish, shrimp and even snails, let’s dig in to the favourite algae eaters for your freshwater aquarium.
First things first, let’s fire away a misconception: There are more algae eater options than buying a Pleco fish or a nerite snail, however they are excellent options. The term algae eater refers to a whole range of species of both fish and invertebrates and each have their own needs and requirements.
Assess what kind of an environment they’re going into so that you can pick the best option for you. Start with looking at water paramaters and rule out any that can’t thrive in your tank. Another thing to consider are things like how much activity there is in your tank, how much activity your algae eater choice will add. What about aggression levels? Another tank mate takes up more water, if your tank is already crowded, then you might want to opt for a larger tank. This way, it will also limit how quickly your water turns bad too!
Will your current fish be okay with the algae eater you choose? Will they bond and be happy together or will one try to eat the other? What about oxygen levels? Pick one that matches your oxygen level - if you’ve just got aeration coming from a filter splashing into the water and you’ve got several fish already, go for one of the lower requirements in terms of aeration. If you’ve got an air pump/bubble stone, aeration from a filter and live plants then your oxygen levels will be considerably higher.
What about the speed of the current? Some fish love it, some fish hate it. Likewise there are some algae eaters that get stressed out with harsher currents and some that love it. How much foliage do you have? And hard rocks? For algae eaters to be full, they need some surfaces for algae to build up on but if you have too much you’re only going to slow your current problem - you may even need two algae eaters to eradicate the algae build up.
We want to make it clear that these things need to be considered as you add more inhabitants to your tank, as all should be balanced, however the good news is that most algae eaters you can pick up from a store can thrive in a range of water parameters. Keep the water quality high with water changes and tap water conditioner if you need it, and they’ll be fine! You’ll mainly just have to focus on making sure that the different personalities for your aquatic citizens mesh well together. Whether you want to learn more about starting a new aquarium or just more advanced nuances to clean your system for better tank photography, this article will explain our favorite options.
Let’s start with The Best Algae-Eating Fish.
Bristlenose Plecostomus (Bristlenose plecos)
Bristlenose plecos are a great addition to most aquariums. These weird looking little suckers will only grow to be around 4 inches long, allowing them to fit into most medium-sized community aquariums. This makes them a valuable alternative to the very common “Sucker Fish” (Hypostomus Plecostomus) that grows to almost two feet long, which is just as surprising as when you got that goldfish from the fair and upon researching how to care for them, you realised that “my first peppa pig fish tank” really wasn’t going to cut it. On top of their impressive algae-eating abilities, they’re capable of being quite the conversation starter. Males develop large whiskery growths on their faces, something that seems appropriate for an aquatic janitor.
They’re also commonly available in two different color varieties, namely gold or albino. This means that they can be quite the dramatic addition to an aquarium and will stand out in their own right. This particular pleco alge-eater will do well in aquariums that have driftwood and plenty of hiding spots. They like a good amount of aeration and because they originate in streams, they’re also fans of water current.
Siamese Algae Eater
Siamese algae eaters are the algae-eating powerhouses of the fishkeeping world. Their generally peaceful nature and ability to eat and control a wide range of algae (including the dreaded Black Beard algae) makes them an asset to almost any aquarium. These guys are particularly ravenous. They thrive best in a group with other fish, but can be territorial around their own kind (They’re pretty chill around other species though). These algae slurpers are part of the carp family and can grow to be about 6 inches long.
Not only will they eat some of the least appetizing forms of algae, they’ll also help control flatworm populations and eat leftover detritus in the aquarium. They also do extremely well in planted aquariums because they’re not known to typically damage the plants when grazing for algae. They like a decent amount of water circulation and low lighting. They typically come in black, white and silver.
Chinese Algae Eater
Chinese algae eaters have been around the aquarium trade for a while. Though they aren’t necessarily the best algae-eaters available, they do offer something that our previously mentioned species don’t.
Although Chinese algae eaters can be docile enough to be kept in a community tank when they’re adolescents, they become much more aggressive as they age. This obviously means that they shouldn’t be kept in community tanks, but this might actually be an advantage for some fish-keepers. These particular suckerfish get on the larger side, reaching about 10 inches at full size. Their large size and agility make them one of the few algae-eaters that can survive with larger semi-aggressive fish or in certain African cichlid tank setups. However, as they age they tend to snack on algae less, and can be harder to care for.
These algae-eating catfish are one of the best species in the trade, hands-down. These are the smallest species in this article, only getting up to 1.5in or so. This and their very calm demeanor make them perfect for most community tanks. These guys do best in groups are do remarkably well in planted aquariums. These guys live in groups of hundreds in the wild, so you’ll want to also get them a few buddies to play with (around 6 otocinclus’ in a tank). Because of this, space might be an issue in choosing this species.
They will not harm the plants and are particularly good at removing brown algae and general new algae growth before it gets a chance to take hold in the tank. They like a decent amount of water movement as they originate from streams.
Twig catfish are one of the best catfish algae-eaters in the hobby and are slowly becoming more and more available. They readily accept a variety of foods and quickly clear a tank of any green algae. However, out of all the algae-eating fish discussed in this article, this particular long nosed species requires the most care.
They need to be in an aquarium that has high oxygen levels and a bit of a current, not to mention pristine water-quality. And, because of their shy nature, they must be kept with accommodating species that won’t out-compete them for food. Assuming your aquarium meets these requirements, a twig catfish would make both an interesting and useful addition to your tank.
What About The Best Algae-Eating Snails?
Mystery snails, a smaller species of Apple snail, are a very popular snail that can be found at almost any local fish store. These snails are true detritivores and will helpfully eat different types of algae, decaying plant matter, and leftover fish food. They only live for around a year, so commitment isn’t a huge issue and they’re easy to care for. They get on well with others and will just slide around nibbling on what they can find. Mystery snails are one of the larger snail species in this article, but they still only top out at around 2 inches, making them a sure bet for smaller community tanks as well as larger ones.
Nerite snails are in high-demand within the pet trade, mainly because they come in a variety of colors and patterns and, unlike most other snails, will not breed in the aquarium. This is a job for most owners as anyone who’s researched snails will see that most commonly, when snails reproduce they’ll create hundreds of eggs. Nerites are intense algae grazers, willing to eat almost any type of algae while not harming any live plants within the aquarium. Zebra and tiger nerite snails will grow to around 2.5cm, the rest are slightly smaller and will mainly grow to around 2cm so these little guys won’t take up too much space in your tank.
Malaysian Trumpet Snail
This particular species of snail is practically required for any planted aquarium. These snails are prized for their tendency to scavenge for food underneath aquarium substrate so if you’ve got a habit of feeding a lonely fish that won't always eat all of what you give them, these little guys will dig in to the rest. They are detritivores and will eat plant and protein matter found underneath the substrate while also coming out to eat soft algae.
They grow to be about an inch and only live for around a year. Their drive to look for food underneath the substrate effectively makes them plow the soil, so to speak, aerating it for live plants. The only drawback is that this species of snail will very quickly and rapidly breed within the aquarium if food is abundant.
What Are The Best Algae-Eating Shrimp?
These little aquatic rubies are one of the most popular ornamental shrimp species widely available. They’ll grow to around 4cm and they’re pretty hardy if their water conditions are kept stable. A word of warning - they’ll easily breed within the aquarium. Cherry shrimp are great at eating different types of hair algae and will also eat leftover fish food. They come in a variety of colors (though a bright red is the most common) and make beautiful tank mates if kept with smaller fish that won’t hunt them.
Amano shrimp are the best algae-eating shrimp species. Their larger size (2in) makes them better able to defend themselves in community tanks, setting them apart from the Cherry shrimp. This species is great at eating various types of soft algae as well as decaying plant matter and some leftover fish food.
This species from Sulawesi is appreciated for its gorgeous colors but unfortunately not the easiest to keep due to their rather specific demands when it comes to water values. They are great algae eaters, though! In fact, a large part of Sulawesi shrimp keeping actually consists of deliberately growing hair algae, micro-algae and biofilm for them to feed on.
Unfortunately, unlike Amano shrimp and cherry shrimp aren't one of those species you can plop into almost any type of aquarium as an algae cleaning crew. However, if you do happen to have a peaceful Sulawesi setup lying around be sure to consider them. They are sure to keep the aquarium super clean and are a fascinating and unique addition to your stock.
So there we have it. If you’re new to the hobby we’d suggest a bristlenose pleco if you want a fish, because they’ll take up the least space (Otocinclus Catfish require friends). We’d say the best pick would be the nerite snails for their colours, size and the inability to breed if you’re opting for a snail. For the shrimp options, we’d go with the cherry shrimp for their hardiness, size and appearance.
You might also be interested in Freshwater Clean up Crews!
Thanks for checking out this Fish Article! Here's a list of our other popular articles: