To help prevent cruelty to fish, it should first be established what constitutes cruelty. The law itself is somewhat open to interpretation as to what is legal and illegal. Ethically speaking, anything that can harm the fish in any way or cause its quality of life to be lowered can be construed as cruel. Keeping the fish in an unsuitable environment, for example a traditional goldfish bowl, an aquarium that is too small, an aquarium with no filtration or without a heater should one be required or keeping small fish, usually bettas, in a vase with a plant or in a small jar is inhumane as these conditions are inadequate for fish. Failure to provide suitable housing for fish leads to problems with water quality. Poor water quality is probably the biggest cause of death and disease for fish. While it is not always the fault of the fishkeeper, the water quality should be monitored regularly to ensure that it is at the very least at a satisfactory level for the fish. Ammonia and nitrite should not be present and nitrate should be kept as low as possible. The aquarium should be cycled before any fish are added and this should be done using an alternative source of ammonia. Using fish to cycle a tank exposes them to ammonia that could injure or potentially kill them. The fishes’ requirements of pH, temperature and hardness should be researched and the water should be adjusted accordingly if needed. If disease does occur even after taking precautions to prevent it, it should be identified and treated as soon as possible. Tankmates should also be taken into serious consideration. Keeping small fish with larger predatory fish would result in the smaller fish being eaten, and is therefore cruel. In creating a community tank, different fishes’ needs should be thought through and compared, for example a cichlid needing water with a high pH level should not be kept with a discus needing more acidic water. Insufficient companionship could result in major stress for some fish. If a fish would naturally live in a shoal, then keeping it alone could cause it to become ill or even die.