Caring for the water in your aquarium is important and can be somewhat complex. Even a child’s simple bowl fish needs water that meets certain specifications. Whether you are a casual pet owner or a serious aquarium hobbyist, here are some simple facts to consider.
At the most basic level, all aquarium water should be carbon filtered before it is introduced to the aquarium. This can be accomplished in a variety of ways, whether through a whole house carbon filter or a small drinking water system. This is primarily about chlorine removal, though there are many other contaminants removed by carbon filtration that your fish will be glad you removed. Additionally many aquariums have integrated carbon filters that continually cycle the water. This helps to reduce the waste byproducts from the fish. In some cases these systems are small and ineffective, but can easily be upgraded to more robust equipment.
Aquariums should never use softened water, as it contains elevated levels of sodium and will be harmful to the fish, especially fresh water varieties. Salt water fish require exacting measures of specific types of salt and minerals, and using soft water will complicate the calculations to get the water right. It’s ok to use softened water if it will be passed through a reverse osmosis system or otherwise be demineralized before use.
For more complex aquariums with exotic species, plants, or salt water species, it’s best to start with demineralized or DI (deionized) water. DI water can be made by steam distillation which requires tremendous amounts of electricity, or through reverse osmosis or by using special resin based filter cartridges. Any of these methods will reduce total dissolved solids (TDS) to very low levels, making it much easier to control the final water product. If you are working with DI water it’s a good idea to own a TDS meter in order to quickly and easily measure the TDS content of the water. You should also be aware that water low in TDS may also have a low ph, which may or may not matter depending on your specific situation. Which leads us to the next consideration.
It’s important to be able to analyze the water for elevated levels of contaminants and ph, both before and after it is introduced to the aquarium. Inexpensive test kits with easy to use test strips are available for this task, and are a must for any serious aquarium owner.
With some inexpensive filtration equipment and a little loving care, your aquarium water will be the envy of every fish in the sea.