In our effort at keeping algae away from our tanks, algae eaters can be great allies. Here is a short list of some of the best algae eaters I know. If you know any other fish or invertebrates that should be added to this list or would like to add some information to this list, please use the comment box bellow. Thanks! Name Pros cons Otocinclus catfish Otocinclus affinis Won’t damage plants. Eats green and brown algae. Peaceful fish. Ideal for small tanks Acclimation can be difficult. Common pleco Glyptoperichthys multiradiatus Hypostomus punctatus Eats green, brush and brown algae Will grow really large. May cause havoc in planted tanks. Bristlenose catfish Ancistrus sp. Good algae eater. Ideal for small tanks. Hardy fish. NA Siamese Algae Eater Gyrinocheilus aymonieri Eats green, brush and brown algae Can be easily confused with the Flying Fox. They also eat fine leaved plants including mosses, hairgrass, and mayaca. Chinese Algae Eater Gyrinocheilus aymonieri NA Will eat less algae as it grow older. Can be aggressive. Will grow quite large. Amano shrimp Caridina japonica Fairly hardy. Eats most types of soft algae and won’t eat plants

Description Blue Green Algae (BGA) has nothing to do with other types of algae usually found in aquarium. This unsightly and potentially hazardous primitive life-form is notoriously hard to get rid of and is the bane of many an aquarist. Blue Green Algae is actually not an algae but rather Cyanobacteria, a group of bacteria capable of photosynthesis. It appears as thick sheets of blue-green, purple, black or brown slime coating the tank substrate rocks and plants. The slime is actually the protective membrane the bacteria forms around the colony. If left to over-run the tank, it will kill your plants and may also kill your fish (some species of cyanobacteria produce toxins). Once it is well established, the water sometimes smells foul. Blue Green Algae in one of our oldest ancestor. Unfortunately, the more primitive a life-form is, the less it needs to grow and adapt. Blue Green Algae is usually more tolerant to extreme environments than algae and can be found in locations where algae don’t grow. It can fix nitrogen and may therefore occur in tanks with zero or very low nitrates (but possibly high levels of other nutrients). In its most common form, the Blue Green Algae is microscopic and harmless. We can’t see it but it’s there, floating around, waiting for the ideal location/condition to grow onto its next life-stage and begin a colony (the slimy stage). In most case, the ideal location is a dead spot with low oxygen, low water movement and lots of organic waste. Prevention Dose nitrates (NO3), add powerheads to aid circulation, frequent partial water changes, do not over-feed and make sure your substrate (if any) is well oxygenated. Treatment Oxygen: As a result of the complex chemical process that allows it to fix its own nitrogen, oxygen is toxic to the Blue Green Algae (this is actually why it likes death spot and low oxygen).

Image by Kai Schreiber Description Black Brush Algae is a form of red algae (Rhodophytes) in the genus Audouinella. While most Red Algae only thrive in saltwater conditions, a few of them have adapted to freshwater conditions and the Black Brush Algae is one of them. The Black Brush Algae does have a photosynthesizing auxiliary pigment called phycoerythrin which absorb blue light and reflect red. For that reason, Black Brush Algae is usually black to purplish-gray instead of green like other algae. It forms short hairs (1/4″ long) that grows closely packed together. It grows on slow growing plants and solid surfaces such as decoration and substrate. When growing on plants, in usually grow around the edges of the leaves. Cause Unstable or too low Co2 levels seem to be ideal for the black brush algae to grow. An imbalance in nutrients will also trigger this problem. Treatment: Oxygen: Can be successfully treated with a syringe of hydrogen peroxide. Overdosing peroxide will harm/kill your fish so I recommend no more than 1 ml of peroxide per 5 gallon. It works well but can’t be considered as an efficient treatment. Co2: It’s been noticed that red algae are especially troubling in waters with plentiful CO2. Increase levels slowly to 30ppm will help lot. Try to keep Co2 levels as stable as possible. Overdosing Flourish Excel can be used as an alternative to CO2. Fish: Few fish will eat red algae. Siamese Algae Eaters and the American Flag Fish are known to eat it. Please let me know if you know other fish that eats Black Brush Algae. Nutrients: In planted aquarium, the best way to eliminate Black Brush Algae is to let the plants out-compete the algae for the nutrients

As big as cat, 35 cm long, this goldfish could be the biggest.