Wellbeing and health of fish and plants are largely dependent on the quality of water. It is known that the composition of the water in the tank must be as close as possible to the natural conditions in which our fish lives. Also if we will have correct water parameters it may be easier to breed the fish.
Taking into account the above indicators of water you can easily guess that tap water is not good for our fish. Tap water is poorer in nutrients that fish and plants require for proper development. That is why we should add special components to improve it's quality.
Before you pour water into the aquarium you should leave it for several hours to a day to remove unwanted components, which are poisonous to fish: chlorine, fluorine, etc. Of course, these gases can be neutralized by special formulations designed for this purpose, such as sodium thiosulfate to neutralize the chlorine.Increasingly
Temporary hardness can be neutralized by boiling the water or mixing with distilled water (making sure to take into account the fact that distilled water is devoid of any minerals and nutrients). Permanent hardness can be neutralized by suitable ion exchange or chemical agents which can be found in shops.
If you have doubts about the water quality you can perform a simple bio-test. After filling the tank with water put Daphnia in it for one day. If they survive, the water is suitable for fish.
When filling the tank with water you should not pour water directly on the substrate (water jet breaks the prepared composition of our ground and can damage plants). It is best to direct the stream of water to open hand or dish placed on the substrate.