Fresh water aquariums can house both tropical fish and cold water fish depending on your choice with each group of fish possessing different requirements. Tropical fish consists of Tetras, Barbs, Danios, Rasboras, live bearers, Anabantoids and bottom dwelling fish such as Loaches and Corydoras.
Tetras consist of the popular Neon Tetra and Cardinal Tetra and certain unheard of fish such as the Phantom Tetra, Diamond Tetra, Congo Tetra and Bleeding Heart Tetra. Other Tetras include the Splashing Tetra, Rummy Nose Tetra and Lemon Tetra. Tetras are shoaling fish and should be kept in groups of five or more since they feel safer in large groups. Danios such as Zebra Danios and Pearl Danios are also shoaling fish and look best in shoals of five or more.
Barbs consist of the popular Tiger Barbs, Five Banded Barb, Cherry Barb, Checker Barb and Tinfoil Barb. Barbs are considered to be fin nippers and are not recommended to be kept with fish that have long flowing fins.
Anabantoids consist of Gouramis and Siamese Fighter Fish which are also known as Betta Splendens. Gouramis consist of the Pearl Gourami, Dwarf Gourami, Thick Lip Gourami, Kissing Gourami and Honey Gourami. Betta Splendens consist of the half moon variation, Delta Variation, Super Delta variation, Veil Tail variation, Plakat variation and the wild type. Betta Splendens cannot be housed together and the males will fight if kept together. Betta Splendens are best kept individually in 3 gallon aquariums with no tank mates since they are semi aggressive fish. Both Betta Splendens and Gouramis breathe air from the surface of the water and should not be kept in Lilly vases.
Livebearers such as Guppies, Mollies, Platys, Swordtails and Halfbeaks are community fish and do not harm other fish. These fish are known as livebearers since they give birth to free swimming fry and do not lay eggs. It is possible to get various variations of livebearers such as Sailfin Mollies and different colored Guppies, Swordtails and Platys.
The most popular Cichlids consist of the Oscar, Discus and Angelfish. Angelfish can be kept in a community setup when they are small but they do best in a species only tank. Oscars grow to be a foot long and are aggressive fish therefore it is recommended to keep them with large semi aggressive fish. Discus fish are delicate and require pristine water conditions and discus are not recommended for beginners.
Catfish such as Loaches and Corydoras are best suited in community aquariums. These bottom dwelling fish work as scavengers and eat the uneaten food in the aquarium, but it is important to provide sinking pellets to these fish on a regular basis. Plecostomas are also known as sucker mouth catfish and can help clean the algae in your aquarium. Their diet must be supplemented with algae pellets and driftwood for them to gnaw on. The common Plecostomos grows up to a 16 inches and are not ideal fish for small aquariums. Bottom dwelling fish cannot eat fish poop as it is commonly believed and hence regular water changes with filtration is required even if you keep these fish.