FishKeepingAnswers.com is reader-supported. When you buy through links on our site we may earn a commission.
Over the last 10 years or so, the popularity of Red Cherry Shrimp, along with many other dwarf shrimp species, has skyrocketed. When shrimp were once only ever considered fish food, they are now a staple of the hobby, being sold in their millions worldwide.
Yes, Red Cherry Shrimp eat algae! Algae make up a major part of a Red Cherry Shrimps diet. Red Cherry Shrimp tend to prefer eating the soft green and brown algae, especially diatom algae. They will also pick at Black Beard Algae, although they don’t eat Black Beard Algae as well as Amano Shrimp will. Red Cherry Shrimp are often added to mature fish tanks as a way to control algae and to prevent it from taking hold
Will Red Cherry Shrimp Eat Algae?
In my experience, Red Cherry Shrimp are great algae eaters. Algae make up a large portion of a Red Cherry Shrimps’ natural diet.
Red Cherry Shrimp spend much of their day picking at agae, eating tiny mouthfuls all day long. Beacause Red Cherry Shrimp only eat very small mouthfuls, they can not be relied upon to be the sole solution to algae in an aquarium.
There are many fish that do a better job of algae control than Red Cherry Shrimp, and I look at some of them in this article. Red Cherry Shrimp should be considered a small part of the solution to algae in an aquarium.
Many aquarists would be surprised to learn that a small amount of algae in an aquarium isn’t a bad thing. In fact, many, including myself believe algae can actually be beneficial to a fish tank ecosystem.
Will Red Cherry Shrimp Prevent Algae?
Red Cherry Shrimp are great at preventing algae from forming in an aquarium. They take a two-pronged attack which can help prevent algae from taking hold in the first place.
Red Cherry Shrimp help prevent algae by;
- Eating the starts of algae as they begin to form. The Red Cherry Shrimp will often eat the very first small pieces of algae that form and thus preventing the algae from spreading. This is especially true of the hair algae which tend to form long strings or hair-like lengths.
- Consuming uneaten pieces of food that the fish leave. Small pieces of food that fall down between decorations and behind filters often end up out of reach of fish. These morsels of food break down and cause nitrates in the aquarium to rise. Elevated nitrate levels often lead to algae blooms.
If you are unsure of your aquarium water parameters, invest in a good quality water test kit. I currently use the API Master Test Kit as it measures pH, Ammonia, Nitrite, and Nitrate. I have found it to be the most accurate test kit for the money. You can check the current price of the API Master Test Kit on Amazon.com here.
Which Algae Will Red Cherry Shrimp Eat?
There are many different types of algae that can form in our aquariums. Some of the Red Cherry Shrimp will eat, and others they won’t eat.
Green Dust Algae
Green Dust Algae is probably the most commonly seen algae in our aquariums. It forms a layer that can spread over everything in our aquariums including on the glass, rocks, decorations, and plants.
A small amount of green algae in an aquarium isn’t a bad thing, and it can even make a tank look more natural. However, once it spreads across the glass it can make a tank look unsightly and if left unchecked on plant leaves it can eventually kill the plant.
Red Cherry Shrimp will help in the battle against green algae, although they won’t solve the problem like a Bristlenose Pleco might.
Brown Diatom Algae
Brown Diaton Algae is most frequently seen when tanks are newly set up, although it can appear at any time.
Red Cherry Shrimp are not as efficient at eating Brown Diatom Algae as an Otocinlus is, but neither the less they will eat it and help to keep it under control.
Brown Diatom Algae is a very soft algae that can be easily removed from the glass with a sponge or even just using your fingers.
Black Beard Algae
Black Beard Algae is one of the most instantly recognizable algae in the hobby. The distinctive beard-like growths that appear as clumps all around the tank can prove a real challenge to get rid of.
Red Cherry Shrimp can help prevent Black Beard Alage from forming as they eat the algae starts as soon as they begin to form. Red Cherry Shrimp are unlikely to tackle a major infestation of Black Beard Algae.
Red Cherry Shrimp should be considered part of a preventative package to stop Black Beard Algae from taking over a tank rather than a solution to the problem that has already begun.
If your tank has a lot of Black Beard Algae, consider adding Black Mollies or Siamese Algae Eaters, both of which will actively eat the Black Beard Algae.
Which Algae Won’t Red Cherry Shrimp Eat?
Although there are some algae Red Cherry Shrimp will eat, there is also a number they won’t even consider eating. These include;
Green Spot Algae
Green Spot Algae is a very hard, green algae that can form anywhere in the aquarium including on the glass, on rocks, or on plant leaves.
Green Spot Algae is so tough I don’t think there are any shrimp or fish that choose to eat it. The only freshwater aquarium inhabitant that I have come across that will eat Green Spot Algae are Nerite Snails.
Nerite Snails have specially adapted mouth parts that can scrape the Green Spot Algae off whatever it is clingy to.
Blue Green Algae
Blue-Green Algae isn’t actually algae, but rather it is a Cyanobacteria. Cyanobacteria are a group of bacteria that get their energy from light via photosynthesis, just like algae and plants do.
I am not aware of any shrimp, fish, or even snails that will eat Blue-Green Algae. The only successful treatment I have found is using Maracyn (which you can order from Amazon.com).
Staghorn Algae looks a lot like Black Beard Algae, although it grows in a distinctive way that resembles the horns of a stag.
Red Cherry Shrimp won’t eat Staghorn Algae, although Amano Shrimp might.
How to Encourage Red Cherry Shrimp to Eat More Algae?
Whilst Red Cherry Shrimp eat algae, they might prefer to eat other foods in the aquarium. Below I have listed some ways you can encourage your Red Cherry Shrimp to eat more algae.
- Feed less fish food – Red Cherry Shrimp make a great clean-up crew and they will happily consume any food that the fish leave. If you want to encourage your Red Cherry Shrimp to eat more algae, reduce how much you feed your fish, and as a result, reduce the amount of food that the fish leave. By reducing available food, you will make your Red Cherry Shrimp eat more algae.
- Remove as much algae yourself as you can – Whilst it may seem strange to remove the algae in an attempt to get the Red Cherry Shrimp to eat more, the reality is Red Cherry Shrimp are better at removing the starts of algae than they are at eating huge clumps. They are better as an algae preventative than they are an algae solution
- Add more Red Cherry Shrimp – The more shrimp you have, the more algae they will consume between them. As a general rule of thumb, you want to keep between 3 and 5 Red Cherry Shrimp per gallon of water. For example, a 40-gallon tank will need between 120 and 200 Red Cherry Shrimp (but don’t worry, they reproduce really quickly!).
Can Red Cherry Survive On Algae Alone?
Although Red Cherry Shrimp will eat algae, it isn’t enough to sustain them long term. Algae make up a small part of their diet, but they also need other food sources which might include flake food, bloodworms, or sinking pellet food.
I feed my own Red Cherry Shrimp colonies a mixture of sinking foods which includes flake food, sinking pellets, and Repahsy gel food. I also add bloodworms, tubifex worms, and Brineshrimp to their tanks.
If Red Cherry Shrimp are only fed algae their numbers will quickly decline and the colony will usually die out.
Red Cherry Shrimp also eat the biofilm that forms on all surfaces within an aquarium. Biofilm takes many months to form, which is why Red Cherry Shrimp often do better in an aquarium that is established than a newly set up one.
What Other Shrimp Eat Algae?
There are many other shrimp in the hobby that will eat algae. Some are highly available and super hardy, others may take a bit of tracking down and can prove to be more delicate, requiring us fish keepers to pay more care and attention to their needs.
Amano Shrimp were popularized by the world-famous aquascaper, Takashi Amano. Takashi Amano used many thousands of Amano Shrimp in his aquascapes because of their desire to eat algae, including Black Beard Algae.
Amano Shrimp are extremely hardy (I once had one live in a bucket of plant trimmings in an unheated garage for nearly a month!) and have a voracious appetite for algae.
Amano Shrimp are often recommended both as a preventative to Black Beard Algae and as a cure if Black Beard Algae has begun to take over an aquarium.
Do Amano Shrimp Eat More Algae Than Red Cherry Shrimp?
Red Cherry Shrimp are great algae eaters, but they are nothing compared to Amano Shrimp. Firstly, Amano Shrimp are considerably larger than Red Cherry Shrimp, but they are also algae-eating machines.
It is said that a single Amano Shrimp will consume the same amount of algae as 8 Red Cherry Shrimp.
Amano Shrimp are also better at reducing algae once it becomes a problem. For instance, if I was dealing with an explosion of Black Beard Algae, I would rather have 10 Amano Shrimp than 100 Red Cherry Shrimp.
Red Cherry Shrimp are well-known algae eaters. Each individual Red Cherry Shrimp only eats a tiny amount of algae, so you might need an army to keep the algae in your aquarium under control. The good news is Red Cherry Shrimp reproduce quickly and a group of 5 can become a group of 500 in less than 6 months!