Aquarium Algae

What is Algae?

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in land plants.
So If the water in your fish's home is green, then algae is growing in the water, which shows that the water contains too much dissolved fish waste. You should change some of the water in your fish's home every day, until the water in your fish's home is clear again.
How much water should you change? Don't overreact and change too much water at one time. Change 20% of the water once each day until the green is gone, then change 20% of the water twice a week.
Don't change more than 20% of the water in one day, unless you have a catastrophe, and green algae is not a catastrophe. Click here for information about changing water in your fish's home.
Blocking Light
Algae also gets nutrition from sunlight and strong artificial light. If your aquarium is near a window then you should consider shifting your aquarium or using window shades. If you keep the lights on in your aquarium then you should reduce the amount of time you keep the lights on. A timer device is a useful gadget that controls the number of hours the light is switched on when you are not present.
Using a Sponge
A good way to control algae is to use a sponge to clean the inside of the glass while changing water. While using a sponge you should keep in mind that the sponge should not be used for anything else and the sponge you use should have never been exposed to chemicals. You can also opt for magnetic cleaners to remove algae from your aquarium. The benefit of using magnetic cleaners is that you do not have to get your hands wet while using them. Many online and retail pet stores also sell sponges that are attached to a long handle. These sponges are good for people who want to clean difficult to reach areas. Using razors to clean algae is not a good idea since razors scratch glass. If you have an acrylic aquarium then you will need to use a special sponge or magnetic cleaner meant for acrylic aquariums.
Note
If you have a current algae problem then you should change 30% water in your aquarium, stop feeding your fish for 4 days and cover the aquarium with a cloth to keep it dark. Low levels of nitrate along with darkness with kill algae. This step should only be performed if you do not have real plants in your aquarium. While controlling algae you should note that fish can live without food for 7 days without any problem. Chemicals should preferably not be used since these chemicals mess up the water chemistry. Many commercial algae controlling products are known to kill snails, invertebrates and plants so if you do plan to use these chemicals then you should use them with care.