The best you can have is coralline algae. It’s a variety of colors, mostly purples and pinks, and will cover the rocks, filter intakes, powerheads (if you have any); it will even grow onto snail shells. It’ll start to appear on its own after 5-6 months, but the growth will be slow. Calcium (which is necessary for coral growht anyway) will speed it up.

Coralline algae is an encrusting algae, and it won’t be bothered by most snails or algae-eating fishes. Some animals might pick at it, and you’ll see who any culprits are soon enough. Coralline is also very hardy, and will out compete almost any other algae in tank. Research has been done to determine if chemicals released as waste products kill cyanobacteria, but the results have been inconclusive.

Also good is just about any type of caulerpa…in the sump. Caulerpa is extremely fast growing, and will soak up nutrients (especially nitrates and phosphates). You can also break off pieces to supplement the diets of algae fishes, such as tangs. However, caulerpa, like many green algaes, releases waste that yellows the water. Not only is this unattractive, but it also alters the specturm of your lights, which will adversely affect your coral growth. If you have caulerpa in a refugium area, be sure to filter the water through activated carbon to absorb the colorful waste.

Bad algae include most of the microalgaes:
-Die hard slime algae
-The ever-bothersome hair algae
-The dreaded cyano
-Virtually-uncurable bubble algae
References :
Stuff I’ve read over time