In order for fish to thrive, water must be similar to that which could be found in their natural environment. Poor water quality can cause fish stress, illness and even death. Regular testing of the water is crucial, particular with a new aquarium, in order to keep parameters like Ammonia, Nitrate, and Nitrite in check. High levels of these can cause poor fish health or death, and may be a sign the filtration is not working efficiently. Just dip a strip directly into your aquarium and use the colour-coded chart to determine if your water is safe, or if adjustments are needed.