How to cope with Blue-Green Algae
The blue-green algae conditions occur where tanks are over stocked with over-fed fish and only partial water changes are carried out which usually leads to a high level of water pollution and excessive accumulation of biological materials: such as organic waste. This situation usually results in "Mats of Blue-Green Algae" at the base of the tank.
The blue-green species are the ones that should give the greatest cause for concern because of the conditions that leads to their growth.
In case of the other two types. (The green and brown varieties), conditions which stimulate growth will not generally be harmful to fish, unless they are extreme. Therefore, correction of conditions is absolutely essential where blue-green algaes are concerned.
Though blue-green algae is very difficult to eradicate from the tank, you can remove it by scraping the glass and scrubbing the gravel and plants. However, the most important thing is to make sure that you prevent it by maintaining your aquarium tank very well through regular water changes and aquarium cleaning. Also avoid overfeeding of your fish since this is one of the main cause of blue-green algae.
Treatment with an algal remedy may remove the algae, but it will not re-establish healthy conditions for the fish unless you change up to half of the water in the aquarium.
Resources
Tropical Fish Secrets - Definitive Guide to Everything You Need to Know About Tropical Fish. Plus 2 GREAT BONUS BOOKS!
All Your Goldfish Questions Answered - Discover the quick and easy secrets to having happy and healthy Goldfish.