The hobby of fish keeping is much more difficult than it seems. It is also directly dependant on science. The bacterial cycle is one aspect related to science. As is how different filters work. Water conditions such as temperature, ph, and salinity play a big role in successful fish keeping as well. Science and Fish keeping go hand in hand. When a tank is first started fish waste and excess food begins to decompose at the bottom. One type of bacteria breaks it down to ammonia, which is highly poisonous to fish. Then a second type of bacteria breaks down the ammonia to nitrites, nitrites are also moderately pois