Why do tropical fish need hard water?

Tropical fish do not necessarily need hard water. Some tropical fish species actually prefer soft water, while others can tolerate a wide range of water conditions. The water hardness requirement for a particular species of tropical fish will depend on its natural habitat.

In general, tropical fish that come from regions with soft water, such as the Amazon rainforest, will prefer soft water in the aquarium. These fish may include tetras, rasboras, and angelfish. Tropical fish that come from regions with hard water, such as the African Rift Lakes, will prefer hard water in the aquarium. These fish may include cichlids, barbs, and rainbowfish.

It is important to note that the water hardness requirement for a particular species of tropical fish can vary depending on the individual fish. Some fish may be more tolerant of changes in water hardness than others. If you are not sure what the water hardness requirement is for a particular species of tropical fish, it is best to err on the side of caution and provide the fish with soft water.

You can adjust the water hardness in your aquarium by adding or removing minerals. Minerals such as calcium and magnesium increase water hardness, while minerals such as sodium and chloride decrease water hardness. You can also purchase commercial products that will adjust the water hardness in your aquarium.

It is important to test the water hardness in your aquarium regularly to make sure that it is within the preferred range for your fish. You can purchase water test kits at most pet stores. If the water hardness in your aquarium is not within the preferred range for your fish, you can adjust it by adding or removing minerals.