The water source used as a base for nutrient recipes should always be evaluated. The quality of the water source can really affect your hydroponic production and your system management across the crop cycle.

It is important to test your water before starting any hydroponics project in order to know if anything must be fixed before running your project.

Most of the time, water for hydroponic projects comes from public utilities, wells, or rain. Each of these options can present different characteristics:

Municipal water
This type of water is distinguished for the presence of chlorine. It is common to use municipal water in small projects. However, due to the cost, this is not the first option for big growers. Municipal water is treated with chemicals such as chlorine to avoid illness in people due to the presence of different microbes. Chlorine can affect water pH and damage sensible crops. It is good to know chlorine can be removed from the water before adding nutrients.

Water from wells
This type of water can be high in some minerals like Carbonates. In addition, water from wells does not have any previous treatments, meaning pathogens with the potential to make your crop sick can be present. There are also good laboratory tests you can use to test your water for any potential pathogens affecting humans or plants.

Rainwater
This type of water can have great quality, is free of additives, and has low mineral content. Usually, only in places closer to the sea, sodium may be in high quantities. However, depending on where you are located and the climate present, collecting the amount of water necessary to run a hydroponic system can be a challenge.

Surface water
Surface water refers to the water coming from rivers, lakes, or canals. The quality of these water sources can be really different. Some places can be more saline than others. You must also take care of pathogens, mostly when the water source is close to urban or horticultural areas.

For more information: 
Hort Americas
www.hortamericas.com