Why is this a problem?

Sunlight is the main source of energy for algae growth. A plain bowl of water will turn green if left in the sunlight for long enough. Aquariums are best positioned in shady locations.

How can I prevent this?

The best solution is to move your aquarium to a shadier location. If this is not possible try to provide some cover to block some of the light entering the aquarium.

If you cannot do this, you can reduce algae by increasing the amount of maintenance.

How do I get clear water again?

Use a Reef One cleaning pad to wipe algae away from the sides of the aquarium. The algae will then be trapped in the filter cartridge.

Keep an eye on the filter cartridge - as the sponge gets dirty remove it and wash it under the tap. By keeping it clear it will continue to trap the algae.

Carry out a series of partial water changes. Continue until the water is clear.

Do not replace all of the water in the aquarium as this will cause worse problems.

For more information see:
cleaning your aquarium