A. This is a very common issue faced when first setting up a tank. All newly setup aquariums must go through a “very necessary process” called the Nitrogen Cycle. A brand new setup doesn’t have the necessary biological culture to sustain a balanced aquatic environment via the break down of harmful chemicals produced by fish waste, left over food, and other organics. By adding beneficial bacteria this introduces the first step to creating a life sustaining environment just as nature intended. As your fish defecate and release harmful ammonia, your newly set up aquarium doesn’t have the bacteria culture to break it down right away. This takes time, and this is the reason why you gradually add fish to your new setup rather than the aquariums full capacity within the first couple weeks. As you introduce the few first residents, they start to feed and release waste into the water, the bacteria which you’ve added in will start to break it down into less harmful chemicals such as Nitrate. In the time being though, while this process takes place, you may experience cloudy water from the ammonia the fish produce due to the lack of beneficial bacteria. By keeping up with your bacteria additives to the water, and again being patient and lenient with the amount of fish you gradually add week by week, the environment within your aquarium will balance itself out, in terms of the amount of fish your aquarium holds versus the amount of bacteria needed to sustain healthy living conditions.