Macroalgae, or seaweeds as they are sometimes called, hold an awkward place in the reef hobby. If they are not being used for utilitarian purposes in a refugium, they are either considered as food for herbivores, or seen as the scourge and plague of otherwise well-run systems. This series will focus on algal marine plants and attempt to highlight their more desirable and beautiful attributes. We will also cover the husbandry and identification for commonly encountered macroalgae, and review some of the interesting habitats macroalgae inhabit in the wild.