Aqua farms can take the form of submerged lattice cages or land-based concrete housings. However, fish farms can damage ecosystems by introducing diseases, pollutants and invasive species. Farmers can often integrate fish farming into their existing farms to generate additional income and improve water management. Fish farming can range from 'backyard' subsistence ponds to large industrial enterprises. Agricultural systems can be expressed in terms of inputs. Large-scale fish farming usually has low economic and labor costs. Natural food production plays a very important role and the productivity of the system is relatively low. Fertilizer can be used to increase fertility, thus increasing fish production. Semi-intensive fish farming requires moderate levels of inputs, and the use of fertilizers and/or supplementary feeding increases fish production. This means higher labor and feed costs, but higher fish yields usually more than offset this. Intensive fish farming requires a lot of effort and the release of as many fish as possible into the pond. Fish are fed supplementary feed, and natural food production plays a subordinate role. This system can pose a difficult management problem due to high stocking densities of fish (more susceptible to disease and lack of dissolved oxygen). Aquaculture is basically the commercial breeding of fish in aquariums or ponds for food production. Commercial fish farming has created profitable business opportunities around the world. As it is well known that fish is an important food and protein source, demand and prices for fish and fish products are increasing rapidly with population growth. Fish farming is a hot topic in some areas. Environmentalists often argue that fish farms are bad for the environment, but proponents point out that fish farms are an important source of high-quality protein. One of the great advantages of aquaculture, however, is that it is a huge business opportunity. Fish farming practices allow farmers to increase the growth rate of their fish with certain feeds, so the fish grow very quickly and can be harvested and sold in a short period of time. Fish farming is very profitable. With proper planning and management, you can easily become profitable within 6 months. Fish farming (often called aqua farming or aquaculture) is the farming of fish and other aquatic animals such as crustaceans and mussels. It uses a controlled, closed environment to raise aquatic animals until they are ready to be processed. While fish farming has some important advantages, there are also some problems associated with it. A key advantage of aquaculture is the ability to provide a consistent supply of fish throughout the year. Fish farm yields are less uncertain because the environment is controllable and it is clear how much fish can be harvested in a given period of time. Fish farming is widely used as it allows for the production of an inexpensive source of protein. Furthermore, fish farming is easier than other types of farming. Because fish don't require a high degree of maintenance, they just need food and proper water conditions and temperatures. The process is also less land-intensive, as the pond size required to grow some species of fish, such as tilapia, is much smaller than the area required growing the same amount of protein from cattle.