Top 5 Algae Eaters for the Planted Aquarium

When it comes to combating algae in the aquarium, balancing nutrients and water quality will only take you so far. The most powerful tool in the anti-algae arsenal is actually the appetite of an algae eater. They come in all shapes and sizes and some are more effective than others. The ideal balance is a non-aggressive animal that doesn't get too big for your tank and eats types of algae that are harder to control yourself. These are the top five algae eaters for the planted aquarium:

1. Otocinclus affinis (Oto cat)

These little catfish are amazing algae eaters. First, they are relatively small and stay under 2" so they can be used in almost any aquarium size. Second, they aren't aggressive and are actually quite fun to watch, often being compared to little monkeys, hopping around from branch to branch. And finally, they eat lots of algae and won't touch your plants. They love brown algae (diatoms) that is common in newly started tanks and also eat all kinds of soft green algae including green dust algae. The only thing to worry about is that they have enough to eat and that there aren't large enough fish in the tank to see these as a snack (angels and other cichlids have been known to try to eat otos). Keep these guys in groups, give them plenty of algae to eat (or zucchini), and they'll keep your tank free of most algae!

2. Caridina japonica (Amano shrimp)

Made popular by Takashi Amano in his nature aquarium style aquascapes, these shrimp are fairly hardy algae eaters that will eat algae that most other algae eaters leave alone. They eat hair algae and other green algaes and even clean up excess food. Although they won't breed in a freshwater aquarium like other shrimp (they need salt water to develop) they are relatively large and are rarely eaten by most normal community fish. Larger loaches and gouramis may try to make them a meal, so be careful. They aren't aggressive, though have been known to eat fry if they are available. Like other invertebrates, they are extremely sensitive to copper, a common ingredient in fish medications.

3. Neocaridina denticulata sinensis var "Red" (Cherry Shrimp)

Cherry shrimp are both pretty to look at because of their bright red coloration, and keep your planted tanks sparkling clean! If you ever need anything cleaned of algae, just put it in a tank with a crew of cherries and they'll swarm all over it, eating all the algae! They eat most types of soft algae and won't eat plants. Even better, they'll breed and given the right conditions, you'll always have an algae clean-up crew. However, they are quite small and are sensitive to water conditions (including copper), and so can be eaten by larger fish (or all babies can be eaten by almost any fish) and are best kept alone.

4. Plecostomus (pleco)

Plecos come in all shapes and sizes, and some are better suited for planted tanks than others. Most plecos grow to be over 12" in length when mature and are therefore not a good idea for most normal sized aquariums. On top of that, they often munch on plants once they get large and can even damage acrylic aquariums with their powerful mouths. Therefore, smaller plecos are the only ones that should be considered for a planted aquarium. One of these smaller plecos is the Bristlenose pleco (shown above), which only reaches 4 or 5 inches in length. There is little that can match the appetite of a pleco and they will keep your tank walls crystal clear. They can even scrape off green spot algae from the glass that other algae eaters can't eat. As long as you get the right kind, plecos are unmatched in their algae appetite and are a fairly good algae eater for a larger planted aquarium. They can also be mixed in with larger more aggressive fish, as they have a pair of barbs on their cheeks that can be used in defense and only mainly come out at night.

5. Crossocheilus siamensis (Siamese Algae Eater or SAE)

Siamese Algae Eaters just barely make it onto this list. Aside from being hard to find and having lots of look-a-likes passed off as SAEs, they have a few major benefits, but along with these come major drawbacks. First, they are some of the only fish to eat red algae and black beard algae. They also seem to love hair algae. However, their appetite doesn't always stop with algae. They also eat fine leaved plants including mosses, hairgrass, and mayaca. Their appetite for algae also seems to wane as they get older until they eat very little of it at all (especially when there is other food present). They can also turn aggressive as they get older, bullying other fish in the tank as they reach their maximum size of about 5 to 6 inches in length. However, a hobbyist's arsenal is limited when it comes to red algae, black beard algae, and hair algae, and these can prove a life-saver as long as you don't have any fine-leaved plants or easily stressed fish.

Shrimp in the Freshwater Aquarium

Crystal Red Shrimp

Keeping freshwater shrimp can be extremely rewarding. If you're bored of fish, or want something other than fish in your aquarium that requires less maintenance, shrimp are a great option. In fact, many people keep tanks of just shrimp! There is just as much variety in the types of shrimp you can keep as the types of fish available. They come in all sizes and colors, range from very easy to keep to quite difficult, and are both easy to breed and nearly impossible in a freshwater aquarium. However, there are a few important things to consider when thinking about adding shrimp in general to an aquarium.

Blue Tiger Shrimp

First, you must consider your existing tankmates (should you have any). Shrimp come in all shapes and sizes, but in general are on the smaller side (around an inch or two). This makes them tasty snacks for larger fish. If you have any large fish, like Oscars or other cichlids, you may want to avoid wasting your money. Also, certain fish eat shrimp in the wild and will quickly consume any you may buy for your aquarium. These shrimp eating fish include loaches, puffers, and some gouramis. Mixing shrimp with fish is also not always a good investment due to the fact that if you buy a type of shrimp that does breed easily, baby shrimp will most likely be quickly snapped up. Therefore, your population will not replenish itself and the larger shrimp will die of old age.

Amano Shrimp

Second, the aquarium is filled with hazards for shrimp that don't exist in the wild, namely filter intakes. Most are shielded somewhat, and this does the job for most adult shrimp unless the filter is particularly strong. However, baby shrimp will be sucked into the filter and, depending upon what type of filter you have, either lead very boring lives stuck in a canister filter or be smashed to death in the impeller. To prevent this, you can either put a piece of stocking over the end of the intake and secure it with a rubber band or plastic tie; cut a hole in a sponge like the types you buy for filter media and stick this over the intake, or switch to air-driven sponge filters. The stocking and sponge options will quickly clog with debris and need to be taken out and cleaned every week or two, so they are quite intensive. The sponge on the other hand is guaranteed not to bubble anything to death, but it will disperse CO2 if you are using it in your aquarium, and they tend to be quite large and ugly (not to mention take up valuable space inside the aquarium).

Cherry Shrimp

Third, make sure the type of shrimp you want matches your aquarium. Neocaridina japonica, or Amano shrimp, grow to be up to 2 inches long and eat algae, but the eggs will not hatch in freshwater. These are best suited for aquariums with fish. Crystal red shrimp can be upwards of $50 per shrimp for a good pattern and are very sensitive to water conditions, but will breed quickly if conditions are right. You wouldn't want to put those in with fish unless you like to give your fish very expensive snacks. Do a little research on the type of shrimp you are interested in and make sure it works with your current or planned setup.

Tiger Shrimp

Finally, shrimp should only be put in a mature tank as they are very sensitive to ammonia and nitrates. They are much more picky about water parameters. I've found that adding certain fertilizers containing trace elements will kill off my Cherry shrimp, but not my Amano shrimp (most likely due to the copper or other heavy metals in the fertilizer). A tank should not be medicated when shrimp are in it. They are often much more sensitive to medications than fish: copper being the most lethal. Even foods should be examined to make sure they do not contain copper.

Overall, shrimp are an excellent addition to an aquarium, and will add color, fun, and help clean the tank!

Cherry Shrimp - Neocaridina denticulata sinensis

Common Name: Cherry Shrimp, Red Cherry Shrimp, RCS
Scientific Name: Neocaridina denticulata sinensis var. red
Geographic Location: Taiwan
Size: Up to 3cm (1 inch)
Temperament: Peaceful
Conditions: 60-82F (ideally 72-78F), pH 6.5-7.5
Skill Level: Intermediate
Minimum Tank Size: 2.5 gallons

Cherry shrimp are some of the easiest shrimp to keep and breed in the aquarium. Often called Red Cherry Shrimp or RCS, these shrimp thrive in planted aquariums, where they eat algae. Juveniles should be purchased, as they adapt better to new aquarium conditions, and at least 10 should be purchased to ensure a mix of males and females. Males are often mostly clear with just a few red stripes and are smaller than females. Juvenile females are similar to males, but as they reach 2-3 months old they develop a solid red color. Around the same time, they should become pregnant with yellow-ish eggs. They carry these eggs around with them in their swimmerettes for roughly 30 days. Unlike other shrimp, the eggs hatch into miniature versions of the adults (there is no intermediate plankton stage). The baby shrimp are very small and are easily eaten by other fish or sucked up into filters. Therefore, if you want to breed these shrimp in any significant numbers, keeping them in a tank of their own with a sponge filter is the best option. Most smaller fish should leave them alone, but do not mix them with fish that have mouths large enough to eat the Cherries, otherwise they may become a snack. Shrimp are also a favorite snack of loaches and puffer fish. Other dangers include ammonia and nitrite. These shrimp are highly sensitive to these two, and will be the first to die if there is a spike in either.


I've kept Cherry shrimp on and off for about a year now, and they are definitely worth having a tank of their own. They eat algae (and are therefore a handy cleaning squad for any algae covered plants you put in their tank), they are colorful, easy to breed, and are entertaining to watch. They are vulnerable to larger fish and chemicals though, so be careful what you put into your water (copper can also prove lethal to these invertebrates) and if you want to expand your flock, keep them in a tank without other fish to snap up the babies.


The best place to buy Cherry shrimp is online through other hobbyists. They are readily available on Aquabid and through various aquarium forums, often for less than $2 a shrimp. They ship very well too, and can tolerate temperatures as low as 60F. Keep them well fed with algae or algae wafers and keep the water quality high and you will be rewarded with more Cherries than you can give away (or sell)!