Aquarium algae are not really bad. In fact, algae have many of the same benefits as live plants in an aquarium: they produce oxygen and consume excess nutrients. If you can tolerate the appearance, algae is best left alone.
There are various kinds of algae you may find in your tank.
What to Avoid When Trying to Get Rid of Algae:
Algaecides/Algae Killing Products
The reason why it is advised not to use them is that ingredients may not been known and needless to say, buying kinds of products like those are a waste of money especially when the algae itself is harmless.
Some of these products are known to eradicate amphibians and even your aquarium plants.
Solving the ridding of algae by use of biological method
Biological method in this case would mean introduction of animals just to get rid of algae.
Some snails do eradicate algae but you must think twice that after you've solved the algae problem, you'll be dealing with removal of snails which can be quite a labor itself.
Introduction of catfish and cyprinids that eat algae may seem a good idea but do take note that if you have other species/animals like the newts, be sure that your algae-eating fish won't injure or worse, kill your other pets.
There's one catfish which is oftne use to eliminate algae: Chinese Algae Eater. As juvenile, it does consume algae. but on the negative side, as CAEs mature, they lose the taste for algae and will eventually harass your other fish. In large tanks, they can be a trouble to catch and that may require you complete strip down of tanks.
Kinds of Algae
This is not actually a true algae, but a form of cyanobacteria.
Very low nutrients(nitrates) will often contribute to BGA(blue-green algae).
Removal is done by manual picking up of as much algae as possible. Blackout should also be done. Do not allow light to penetrate in your tank.
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They are found usually as brown spots or slime clinging on the glass and possibly on other decors. This kind of algae is quite common in newl-setup tanks.
Low lighting and high silicates are often the causes of this growth. Removal is done by increase of light level but they may disappear as your tank matures.
Green Spot Algae
They are found as circular green spots adhering strongly on tank glass. Excess lighting and excess nutrients will often result to this. A small amount won't do your tank any harm.
Removal is done by scraping them off the glass with the use of magnetic cleaners, brush or razor blades.
Regular cleaning and water changes of tank and avoidance of overfeeding will prevent or at least, control this algae.
This is characterized by the appearance of your tank turning into 'green stew'. High ammonia level, excessive lighting, sunlight exposure and nutrient imbalance are often the causes.
The use of daphnia can be done(without the fish, of course
). Blackout and installation of UV sterilizers will often help.
Another method is the use of barley. they can help absorb the green algae out of the tanks or ponds.
Do not use water changes when trying to get rid of this algae. You are only letting it produce more which can be dangerous as they tend to use up even oxygen needed by the fish.
Hair algae is light green in color and are strands in appearance.
This is often a sign of healthy tank and it benefits the fish by being the food source. However, mass production of this algae can have a negative impact to your tank.
Manual pick up or twisting it on brushes or stick will often help control this algae.