1. Understand Algae and why it occurs
All algae requires light to photosynthesise and nutrients on which to feed. Different types of algae prefer different levels of light and different nutrients. It is true that any body of water suitable for maintaining aquatic life will also offer a suitable home to some of the thousands of species of algae.
Even the cleanest looking aquariums and ponds will contain some algae, it is inevitable! So this is a guide to control the growth of algae, it is normally possible to retard its spread to the point that it is no longer visible or of concern.
Always remember that out of control algae will not harm your fish. It is in fact a symptom of underlying conditions that will actually aid water quality until better conditions are restored. At this point the level of algae will naturally reduce.
2. Lighting can be used to fight algae
Or rather a lack of lighting or the correct lighting! Most common forms of algae require continuous lighting to photosythesise. Broadly speaking most algaes will not start to multiply until they have been exposed to light for a period of 2-4 hours. For this reason we recommend in most instances using a light timer and running the lights for 4 hours on, 2 hours off, 4 hours on. This is not including blue lighting used in the early mornings and evenings. The blue light spectrum is much less useful to most types of algae and therefore less of a concern. When following this advice in a reef tank it is worth considering certain corals and invertebrates do require longer periods of continuous lighting. In this instance it would not be suitable to introduce a break in the aquarium lighting.
The quality of the light is also important, older tubes that need replacing will over time change in colour spectrum and so regularly replacing your tubes will ensure the correct light is being used.
NOTE: Any aquarium that receives direct daylight, or bright in-direct daylight will struggle with algae problems and should be relocated. Ideally all aquariums should be sited away from natural light sources.
3. Do I need to water change more?
Water changing is not always the best answer to any given problem but in almost all cases it will help. There are a variety of ways to reduce the build up of undesirable nutrients and chemicals in an aquarium, however none are as instantly effective as a water change. This is becasue a water change will immediately dilute the effects of a problem whilst its route cause is addressed.
5. Fight Algae with Algae
7. What about my protein skimmer?
8. What eats algae?
10. Red/Brown slime algae
Characterised by its rapid spread over pretty much any surface in the aquarium. This form of algae is very common in new marine aquariums. Typically it occurs shortly after adding the first livestock (including living rock) and will naturally subside as the tank matures. These algaes feed from Nitrite which is more prevelant in new aquaria. As the filter matures Nitrate will be reduced to an effective zero, thus removing this type of algaes food source. Slime Algae also perfers low lighting, often it will be replaced by coarser algaes in new aquaria with powerful lighting.
11. Hair Algae