To set up a proper aquarium, it is necessary to understand the nature of your fish by type and origin. Catfish, for example, come in various species for freshwater or saltwater and are found all over the world. Cichlids come from Africa, South America, and Asia. Each type requires specific conditions, depending on its natural habitat of origin, to thrive in your aquarium.
The African River has slow- and fast-moving sections that carry diverse species. The slow part holds African Tetras. Your aquarium should have a pH of 6.9-7.2 and a temperature of 75-80 degrees F for them. Substrate should be made up of sand or fine gravel with wood and plants for hiding. You'll need moderate light and a filtration system with a slow current. The fast section houses African Catfish and Dwarf Cichlids that need a pH of 7.0-7.5 and a temperature of 77-81 degrees F. For this setup, you'll need to provide open space and an aerated environment with large rocks, no plants, and fine gravel or sand for substrate.
The Southeast Asian River holds Danios, Barbs, and Loaches. You will need lots of plants with proper lighting and fine gravel or sand for substrate. A pH of 6.0-6.5 and a temperature of 79-84 degrees F are preferred. No current is needed.
The Indian River carries Danios, Spiny Eels, Loaches, and Gouramis. They prefer a pH of 7.0-7.7 and a temperature of 70-75 degrees F. You will need to provide bright light, plenty of plants, and fine gravel or sand substrate.
The Australian River holds Gobies, Rainbowfish, and Australian Arowanas, to name a few. To create a favorable environment for them, pH should be 7.0-7.5 and temperature should be 75-85 degrees F. They also require rocks, sand substrate, bright light, and a current to generate clear water.
The South American River is divided into whitewater and clear water. The Amazon is a whitewater river. Piranhas, Oscars, Angelfish, and Hatchetfish are found in the slow-moving parts. Keep a pH of 6.8-7.1 and a temperature of 79-84 degrees F, with open space and driftwood, along with a clay substrate for them. Discus and Dwarf Cichlids exist in the darker rivers and creeks of the rainforest. Set up an aquarium with driftwood, dark gravel, and a peat filtration. The pH level should be 4.5-6.5 and the temperature should be 81-86 degrees F, to match conditions there.
The Central American River house Cichlids and Livebearers. Your tank should have driftwood and rocks and a fine gravel or sand substrate. The pH should be 7.0-7.8 and the temperature should be 72-79 degrees F. Plants can be added for Livebearers. The aquarium should be well lit and a medium current should be provided by the filtration.
The Central American Lake carries more aggressive Cichlids. You will need a pH of 7.5-8.2 and a temperature of 75-81 degrees F. Provide rocks and gravel, no plants, and not much water current.
The African Lakes, Malawi, Victoria, and Tanganyika, house Cichlids known as Africans. They require rocks and gravel substrate. You may need to modify the environment to sand, or rocks and sand with snail shells, for some Africans from Lake Tanganyika. No plants are needed and not much water current. The pH required is 7.8-9.0 and the temperature should be 75-82 degrees F.
The Mangrove Forest is close by an ocean and is brackish. It houses Puffers, Scats, and Tiger Fish. The setup consists of coral, sand, and driftwood. You will need a good filtration system and a pH of 7.2-8.0 and a temperature of 75-82 degrees F. These fish also require a specific gravity of 1.006-1.015.
All of these fish are bred commercially to save on time and money, and to create hardier fish at greater availability. The added advantage to breeding in captivity is that it does not disturb natural habitats. These fish are just some of the more popular breeds.