Algae Overview and ClassificationThe term "algae" seems like a relatively scientific name for a group of organisms. However, nothing could be further from the truth. Algae are not plants at all. Most species of algae used to be part of kingdom Protista, which has since been broken up into separate kingdom. The word "algae" refers to a group of organisms that spans across different kingdoms and can range from being microscopic to being over 60 feet tall, such as kelp. Only a fraction of these species are found in our tanks, and those are the types that I will focus on first.There are two basic types of algae: microalgae and macroalgae. Microalgae are planktonic organisms, meaning that the spores of algae generally float freely and then eventually settle onto a surface. Some types of microalgae include diatoms, cyanobacteria, and dinoflagellates. Macroalgae, on the other hand, are able to anchor themselves to a rock or substrate and grow from there, like a seaweed. Diatoms are a type of microalgae that are formed of silicon shells. Since they are a microalga, they spend the majority of their time in the ocean floating around resting on sediments. Diatoms are usually brown and are generally one of the earlier types of algae to appear in the aquarium.Cyanobacteria are technically not algae at all, but as the name would imply, a type of bacteria that can produce its own food through photosynthesis. Cyanobacteria can range in many colors, but perhaps the most well known example of it is in the red slime that can cover the aquarium if water chemistry is not up to par.Dinoflagellates are a group of organisms that includes an alga-like group and other species of dinoflagellates that range from parasites to the dinoflagellates that can cause red tides. Dinoflagellate algae in the aquarium are usually photosynthetic and can attach to almost anything in the aquarium, forming a brown, snot-like scourge.The green algae, once called Chlorophyta, have now been separated into many different groups. These algae are green due to the chlorophyll pigments in their cells, such as that found in many plants. Chlorophyta algae are the most diverse, ranging from unwanted hair algae to desirable Chaetomorpha.Rhodophyta refers to a group of algae called the red algae, though not all of the algae in this group are red. This group of algae is generally found in more established tanks. Rhodophyta includes the group of desirable algae known as coralline algae, which secretes a hard calcareous shell, similar to some coral. The final group of algae I will be covering is Phaeophyta, the brown algae. Generally, brown algae are found in the ocean as seaweed, such as kelp. However, brown algae can also appear in the aquarium, generally in newer tanks. All these types of algae and more will be discussed in the newsletter. As always, if you wish to contact me, you may either PM me or comment on this post.