Algae's controlled growth can provide positive help in tackling some present-day problems such as disposal of sewage and industrial waste, conservation of water and soil, and improvement of quality and yield of food products. However, their uncontrolled growth causes pond epidemics, water fouling, and now algae as a food. One boom in the last decade has forced man to depend upon seaweeds and other algae to supplement his diet. Researchers in Japan, Germany, and the USA have shown that the nutritive value and per-unit area yield of algae is much more than conventional crops. Porphyry is a red algae which grows in shallow seawater. It is very rich in protein and carbohydrates, a good source of vitamin B and C. It's a common food item in Japan called nori and Britain grifted on toast. In Japan, around 30 million kg of porphyry is used per year as food. Laminia is considered a delicacy in Manipur, India. Ice creams, gelatine, and gracilia are used to show a map of India. Chlorella, a green algae, is more useful than porphyry in terms of its nutritive value. It's comparable to that of a mixture of soybean and Spanish. Chlorella is used as a protein source. Chlorella and spirulina is used as a protein source by space travelers. Algae in industry. Agar, pharmaceutical uses. Funuria type of algae obtained from glopulus furicata. Algae in disposal of sewage. Water-bound domestic and industrial waste is called a sewage. It contains organic and inorganic materials in soluble or suspended form. Although disposal of sewage is mostly an aerobic process, sewage is usually poor in oxygen. It is necessary to treat sewage aerobically before disposal because its aerobic digestion produces unpleasant odor. Its anaerobic digestion produces unpleasant odor. It is a rich source of many inorganic nutrients and such proper treatment sewage can serve as fertilizers. Oxidative breakdown of sewage is carried out in a small tank and oxygen required by bacteria for the process oxidation is obtained from algal growth. Algae as antibiotics. Chlorine obtained from chlorella is effective against gram positive and gram negative.