Keeping water not fish
One of the biggest challenges of fish-keeping is the fact they live in water. It’s something we as land-dwellers don’t fully understand.
Good water quality is essential; look after the water and the fish will take care of themselves.
However, you’d be wrong to assume that clean, clear water means all is well. Most of the poisons that affect your fish are invisible; you’ll only know they’re there if you test the water.
In the wild, water is cleaned, replaced and replenished through natural cycles such as rain or flowing water. An aquarium is a closed environment, so fish waste has nowhere to go with build-up causing sickness and disease. The aquarium filter acts as a sewage treatment works, taking poisonous waste material into harmless substances. Substances that are not dealt with by the filter are controlled through regular water changes. Toxins are diluted by removing waste-filled water and replacing it with fresh water.