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.
Every aquarium at one time or another experiences a bloom of brown algae. You are most likely to see it during the cycling phase of a new tank or while curing Live Rock. Brown algae can also show up at any time in well established tanks. Brown algae is not an algae at all, but a tiny animal called a diatom.The animal is encased in a hard shell made out of silicone dioxide. The brown mats and film you see are composed of billions of diatoms interlocked together by their hard shells.rown algae is not an algae at all, but a tiny animal called a diatom. The animal is encased in a hard shell made out of silicone dioxide. The brown mats and film you see are composed of billions of diatoms interlocked together by their hard shells.