It is impossible to eliminate algae altogether, and you should not be frustrated by the persistent nature of algae to accumulate. What you can do is control the condition under which plant life and fish thrives and algae does not. First, how much light are you allowing into your tank area? If you have light for more than ten hours a day, you are assisting algae grow in your tank, so don’t keep the lights on 24-7. You can purchase algae eating fish if that would fit with your aquarium’s motif. Some fish types that consume algae are three breeds of suckermouth catfish, the Ancistrus, Peckoltia, and Otocinlus. In addition, the Siamese Algae Eater, Crossocheilus siamensis is a great choice for controlling the algae in your tank. If you have a large tank, then the Common Plec is a good choice as well. But they are aggressive fish and do grow to huge size. Saltwater fish that are excellent for algae consumption are most tangs/surgeon fish, or any grazer.
The next step in controlling algae is to consistently change the water itself. By doing this, you are controlling the nutrient levels in the tank, which is crucial. Controlling nitrates, phosphates, and silicates are especially important. Another thing to look for is how you are controlling the iron in the tank. You can include different kinds of plants in your setup so they will compete for iron and other nutrients algae feeds off of in order to how a low opportunity for algae to survive.
Your first battle is likely to be with brown algae, or diatoms, because it appears first by siphoning silicon from the new aquarium tank itself, and unlike other stages of algae, it is unaffected by low lighting levels, so controlling light will not stop it from thriving. You can effectively combat it by changing water and gravel often. Diatoms thrive in conditions where phosphate is low and silicon is high, and this is generally what your scenario will be when you first start your aquarium. As time progresses and the environment changes, brown algae is usually replaced by green algae, because green algae thrives in a higher phosphate environment.
Green algae is apparently delicious and the best way to get rid of it is to bring in those algae eating catish and/or Siamese. Combined with keeping your aquarium only lit for a maximum of ten hours a day and simple manual removal of clumps of green algae, you can control what is typically the most usual and common algae growth in your aquarium.
Red Algae, or Brush, is a real problem because it is difficult to remove manually and most fish won’t eat it. Take care of this pesky nuisance by changing your water to RO/DI water and let your Siamese fish tackle it.
Blue Algae, or Cynobacteria, have photosynthesis, meaning the more light, the more it thrives. It is extremely harmful to both plants, by smothering, and fish, by poisoning. Treat your aquarium with erythromycin but be sure you know what you are doing, as you will need to check for ammonia and nitrate.
By Richard Gilliland