Tap water contains chlorine and other contaminants. These are toxic to fish and, if they aren’t removed or detoxified, will kill your fish quickly. When making new water for your aquarium, it is essential to add a conditioner before putting it in your aquarium.
There are two main types of water conditioners:
- Dechlorinator – eliminates chlorine in the water. These leave things like ammonia and copper. Most of these use sodium thiosulfate as a de-chlorinator.
- Complete Conditioners – Neutralizes ammonia and eliminates metals and chlorine, also helps with slime coats and electrolytes.
Now for some chemistry. If we only needed to remove chlorine, this process would be simple. But when chlorine and ammonia are in the water, the compounds bond together to create chloramine (NH2Cl). Conditioners must first break this bond, then detoxify ammonia and remove chlorine.
Many companies make water conditioners, My preference is Aqueon Water Conditioner.
Depending on your aquarium stock, your pH could be as low as 5 or as high as 9. It is essential to find what pH your fish need and make sure your fish are compatible.