What exactly are algae? Algae is a single or multicellular organism that has no roots, stems or leaves and is often found in water. Algae is broken down into seven groups and within those groups, there are several thousand species and over 700 common types.
So we know what algae is, but what kinds of algae am I likely to find in my aquarium?
- Green Surface Algae – that’s the green stuff that grows on your glass
- Brown/Diatomic Algae – Often occurs in newer aquariums and generally resolves itself over time
- Hair/Brush/Tufted algae – Has the appearance of string, beards, brush bristles or tufts.
- Red/Black Algae – Is quick to overtake plants that are slow-growing, is a reddish-purple color.
- Blue-Green Algae – Is not algae, it’s a bacteria that is not eaten by fish.
Why is this important? Not all algae eaters will eat every type of algae. In order to treat your algal problem, you need to know which type is infesting your tank and why it is there.
In home aquariums, algae feeds off the byproducts of waste such as ammonia, nitrite, nitrate, phosphorous, uneaten fish food and other DOC (dissolved organic compounds). The type of algae that grows (if any) is often determined by the food sources available. Algae growth as well as type is also dependent on the amount of lighting in an aquarium since algae generally uses photosynthesis. To control algae growth, you need to control the quality of the water in the aquarium. The most effective way to do this is with a water change. As we (aquarium keepers) know, water changes are used to dilute toxins in the water which are fed on by algae. Algae can be starved out by removing its food source. Another effective way to control algae growth is by adding large amounts of live plants to help absorb excess nutrients and out compete the algae. Controlling the amount of light in an aquarium is another way to control algae growth. This is most easily achieved by using an auto-timer. Unless a tank is planted with live plants, the only purpose for an aquarium to have a light is to make it easier to see the inside of the tank. Again, since algae feeds off waste products, another way to control its growth is through discipline in feeding the fish. Feeding your fish in a manner that allows none to go to waste will limit the amount of food to the algae.
If your tank is already overgrown with algae, there are quite a few methods to control and eliminate the problem. The first option would be *gasp* to just leave it there. If the algae is not smelly or hindering anything, leaving it there is perfectly fine and may actually do some good. Algae eat pollutants in the water and in turn release oxygen. Many types of algae are easily removed by wiping the surface with a sponge, cloth or an algae scraper (in tough to wipe strains). There are also chemical solutions which are marketed to remove algae but can be harsh on things other than what it is intended to destroy and should only be used as a last resort.
So then, does every tank need an algae eater? Nah – not all tanks develop algae and most that do, it is easily controlled through establishing a strict maintenance schedule. Most algae eating fish are specific to the type they will eat and need a supplemented diet. Often, an algae eater will be so used to eating the supplemented foods; they won’t eat the algae which caused you to buy him in the first place. Algae eaters also produce waste which contributes to the algae problem.
The worst reason for buying an algae eater is “just in case”. If there is no algae growing in the tank you don’t need anything to eat it. Again, not all algae eaters will eat every type of algae. You can’t predict what type (if any) will grow in your tank so you can’t say you need an algae eater when you don’t even know which kind you will (maybe) need. It’s important to remember that adding an algae eater is just adding another fish to your tank – but this fish has very specialized requirements eventually, all algae eaters will require supplemental foods.
Before diving into buying an algae eater, why not take a look at some community fish that may already be in your tank and will enjoy an algal snack. Mollies, platys, guppies, gourami (especially kissing if your tank is large enough), rosy barbs (hair algae), all the other barbs, flag fish (hair algae), most Malawi cichlids will all, to some degree, enjoy munching on algae. None will completely eliminate the problem, but they can help control it to some degree. Here is another bit of info: not all bottom dwellers will eat algae – corydora, loaches, and catfish with large mouths are not good algae eaters.
If you are still wanting that algae eater, here is a quick guide on a couple species along with the types of algae they consume. Remember: Don’t buy an algae eater unless you have something to feed it. If you can’t see any algae, there are not enough algae to sustain an algae eater.
- Pleco (common)
Max size: 12”-24”
Good for: green surface algae, brown/diatom
The common pleco is super cheap, grows insanely huge, lives pretty much forever and grow really fast. Common plecos will often uproot plants so should not be kept in a planted tank. If supplemental food is not given, they will feed off the slime of other, slow moving tank mates. They have big appetites and make lots of poo. I mean foot-long strings hung up on everything like poo Christmas garland. If there’s not tons of poo, the pleco isn’t healthy.
2. Pleco (rubber lip)
Max size: 3”-5”
Good for: green surface algae, brown/diatoms
The rubber lip pleco is best in tanks over 10g. It is a relatively shy pleco and needs plenty of hiding places and should not be stocked with highly active or aggressive fish. The rubber lip pleco in general is plant friendly.
3. Pleco (bristle nose)
Max size: 4”-8”
Good for: green surface algae, brown/diatoms
The bn pleco is great in tanks over 20g. As adults they are territorial and may become aggressive to other bottom dwellers or cave-dwellers. They should have plenty of driftwood for territory and dietary needs.
Max size 1.5”
Good for: green surface algae, brown/diatoms, plant cleaning
The Oto is often thought of as the best AE for small tanks. They work well in most community tanks but are best kept in multiples. They are sensitive to poor water quality but once established, they are pretty decent algae eaters. A round belly is a happy Oto.
5. Siamese Algae eater
Max size: 5.5”
Good for: Red/Black Algae, Tufted, Hair/Brush Algae
The only algae eater known to eat red algae. Lots of plants are a must as well as a tight fitting lid. The SAE do best in schools but can be kept in pairs as well. Unlike most fish, they do not have a very well developed swim bladder so if they stop moving, they will sink.
6. Chinese Algae Eater
Max size: 10”
Good for: nothing
The CAE only eats algae as a juvenile, once it reaches 6 inches, it stops eating algae. As an adult, this fish is very aggressive and is not recommended for a community tank. This fish requires lots of rock or driftwood to establish territory.
Algae eaters can be great to watch and each has their own personality and quirks, but they are not essential for any aquarium. Sure, they can contribute to the controlling of algae in a balanced tank; they really should not be used as the primary source of algal control – that’s your job. Don’t you feel special!