Eradication of encrusting algae could be done simply by periodically scraping the sides of the aquarium or scrubbing the rocks.
For those with plastic plants and a completely white gravel bed, the situation could be more tasking as it would be necessary to bleach the rocks to remove all traces of algae.
However, if you do this, do make sure that you rinse the gravel thoroughly afterwards. Bleach is highly toxic, and even small amounts can have a drastic effect on the aquarium fish.
Since the primary cause of green algae is too much light. The fist step in the treatment schedule should be light reduction then partial water changes and an adequate stocking with natural aquarium plants. A final treatment with an algae remedy should ensure that the problem is eradicated and is at least kept at bay for some time.
One of the factors mentioned above is the use of natural aquatic plants as a means of algae control. This is really more effective than many people think.
For a start, luxuriant plant growth will filter out some of the light keeping algae in check. In addition plants absorb a large variety of chemicals from the water, thereby starving algae of some of their essential nutrients e.g. nitrates (not nitrites).
Surprising as though it may seem, an adequate plant stocking level is approximately 50 small plants per square root of available space.
The treatment I mentioned is the use of an algaecide. I must stress the word "use:" it is very different to "abuse"!
Yet despite this difference, I know that some people will still persist in pouring the chemical remedy into their aquarium and expect the problem to disappear overnight, even though they have done absolutely nothing to alter the conditions in the tank that brought about the problem in the first place.
The conditions I stated above have to be adhering to for any lasting effect to occur! Now that we know how to curb the menace of the green algae, in another article I shall discuss it's ugly "sister" brown algae (the brown encrusting algae whose case is the reverse of green algae).