Controlling Algae in a Freshwater Aquarium


Algae is one of the most annoying problems faced by aquarium keepers. Algae causes the aquarium to look dirty and it also changes the color of the water. Many fish keepers buy expensive chemicals to keep their aquarium algae free but there are simple ways to control algae. This article will elaborate on a few tips for controlling algae.

Regular Water Changes

Algae occurs in aquariums that have unheaten food and high levels of nitrate. This substance derives its nutrition from leftover food and high levels of nitrates from fish poop. The easiest way to control algae is to change partial amounts of water frequently along with siphoning the gravel. If you see a lot of unheaten food in your aquarium then you should consider cutting down on the amount of food you give your fish. You should feed your fish how much they can eat in 3 – 5 minutes and then net or siphon out the remaining food immediately.

Blocking Light

Algae also gets nutrition from sunlight and strong artificial light. If your aquarium is near a window then you should consider moving 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 for acrylic aquariums.


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.

Source by Jason MacParland