No aquarist in their right mind would voluntarily destroy their aquarium life, which they have invested so much time and effort to establish. As such, it is extremely important to keep aquariums absent of dangerous toxins that can leave owners staggering from devastating losses of their tank’s marine life. As it has been, and should always be, prevention is better than a cure.
For example, consider the water source that you intend to use for the aquarium. The use of tap water is strongly discouraged. This is because tap water is treated with chlorine to kill bacteria. Introducing chlorinated water to an aquarium results in the death of bacteria that balances the natural cycle of the tank. Chlorinated water can also lead to the death of fish and other marine organisms.
The death of bacteria will cause an alarming decrease in the amount of nitrifying and denitrifying bacteria that balance the nitrite and ammonia levels in your aquarium. Death of such bacteria will lead to the incursion of your aquarium by very high ammonia and nitrite levels. Ammonia and nitrites are very toxic, disturb the water pH, and endorse the rapid growth of stubborn algae.
Toxins can also be introduced physically into the aquarium by what we call normal daily life activities. It is important that anyone immersing their hands into the aquarium cleanse them with soap and clean water first. Activities including the spraying of perfumes or air fresheners, the application of body lotion, and the distribution of insecticides and pesticides should be done away from the aquarium. These substances can prove harmful to aquarium life and should therefore be kept away. If you happen to use any cleaning sprays for surfaces near or within the aquarium, do not spray them into the air. Instead, spray the cleanser directly on a cloth and then use the cloth to wipe the surfaces.
If you realise that your aquarium has been contaminated, do water changes of 30% to 40% as soon as possible to avoid losing your aquarium life. This is the first step that must be taken before any other measures, but remember to use treated water of the same temperature as the aquarium water.
In the case that chlorine is introduced into the aquarium, you can remove it from the water by placing an aerating in the water with an air pump and a stone. This will release the chlorine into the atmosphere and it is likely that your fish will be saved. However, I would like to re-emphasize that prevention is not only better than a cure, but it is also less costly.