1.) As a home aquarium owner wanting to purchase freshwater fish, there are a few things you must remember; of this, the most important is that you know which kind of fish you want to keep and the other species that can stay together with them. The size of the aquarium determines how many fish you can keep comfortably in it – go by the simple thumb rule of each fish requiring at least 3 inches in each gallon of tank water so they can discover and grow naturally. Freshwater aquarium fish only grow as big as the space granted them, so you know that the more space you give them in tank water, the longer their lifespan will be!
2) Know your fish species: especially for the freshwater aquarium