Inches. -. A shoe size is a numerical indication of the fitting size of a shoe for a person. Several different shoe-size systems are still used today worldwide. In some regions, it is even customary to use different shoe-size systems for different types of shoes (e.g., men's, women's, children's, sport or safety shoes).
Types of Algae. Brown Algae (Diatoms)  This is the first type of algae that begins growing in a new aquarium. It usually grows on the gravel and glass. Unlike other types of algae, this type requires silicates in order to grow. By increasing light levels, this type of algae can be replaced by the more beneficial green algae. Brown algae can easily be scraped off the glass.
It can grow in huge nasty globs on the surface of your aquarium, cutting out light. It can fill your tank and even sometimes trap and kill your fish. Of all the types of algae, itâs hair algae that causes the most problems for the most aquarists.