Many aquarists have been plagued by the algae menace. While algae is a necessary element to keep an underwater ecosystem balanced, it can look unattractive in large quantities and choke your other plants and/or corals. Excessive algae growth is very common in new aquariums due to the nitrate spike, which acts as a fertilizer for the the tiny plants.
If you are just starting out your aquarium, there isn't much you can do to stop the massive algae growth that you are bound to encounter in a short while. What you can do is try to scrub it off of your rocks and remove massive clumps as a means of nutrient export. You can also try to get rid of the nitrates by doing water changes and running a protein skimmer or other form of filtration. One very important thing you can do is use RO water instead of tap water, if you aren't already. If your tap water contains nitrates, it may be the source of your algae problems.
Once you have solved the chemical source of the algae problem, you can now focus on getting rid of the algae itself. To do this, you need a good algae eating crew. There are three main areas where algae will grow: rocks, glass, and sand. Each of these terrains require specific creatures to target the algae.
For the glass, the most effective algae eaters are the scrapers. These types of feeders are able to scrape the glass clean with a textured tongue or mouth. Several types of snails will crawl over the glass, with the most popular being astrea or turbo snails. Other scraping creatures include urchins, which are arguably the most effective glass cleaners.
The rocks are arguably the easiest to get clean, despite their rough and uneven textures. The glass-cleaning snails and urchins work well here and are quite capable of navigating the rock surfaces and scraping them clean. In addition to those animals, crabs make a great rock cleaner, particularly emerald crabs and certain species of hermit crabs. Crabs are well equipped to rip algae out of the rock crevices using their long arms with pincers. Finally, you can also use fish such as most tangs, blennies, and angelfish to eat algae that is growing on rocks.
There is one type of algae that should eventually cover your rocks once the other algae types are gone. This algae is called coralline algae and, unlike most other algae, forms a hard coating over the rocks. It typically takes on a reddish, purplish, or bright green hue, giving rocks an interesting appearance. Most people do not want to get rid of this type of algae, but urchins will readily eat it if you don't like it.
The final algae domain is the sand, which is definitely the most difficult to keep clean. There are some species of snails that are able to traverse the sand, namely cerith and nassarius snails. You can also purchase conches, such as the fighting conch and queen conch, which will eat algae on the sand. Another option is a sand sifting fish, such as the diamond goby, which filters sand through its mouth. Finally, you can also buy a cucumber, such as the tiger tail cucumber, which eats dirty sand and expels it in clean form.
Hopefully this article has given you some insight into how to clean your aquarium of unsightly algae. Although the algae may seem like a formidable threat to the beauty of your aquarium, it is not difficult to control using the appropriate strategies. Good luck!