What’s in your water?

What's In Your Water?

  Without a doubt, one of the most valuable resources on our planet is clean water. The composition of water can vary widely depending on where in the world you are. As a grower, it’s very important that you know what is in your source water. The only way to know for sure what’s in your water is to send it off to a lab for analysis. A complete water analysis can be performed for around $50. Having this knowledge is invaluable as a grower. 

 

  A complete water analysis will show you the chemical makeup of your water and alert you to potential problems. It can also provide peace of mind and assurance that your source water is of great quality. Because water quality can change seasonally, it is advised to perform at least three or four water tests per year. Be sure to keep records so you can monitor the changes in your water year after year.

 

Water Quality Characteristics

 

  Determining your water quality is one of the first major steps for any horticultural facility. It will play a major role in the overall success of your crops and is the foundation of an optimum fertilization program. The major characteristics of water quality are 

 

  • pH

  • EC 

  • Alkalinity 

  • Hardness 

  • And the overall levels of soluble ions that are present in the water

 

You may also need to test for biological contaminants and plant pathogens as well. The results of your water analysis will determine whether you are ready to grow or if you require carbon filtration, reverse osmosis or other filtering methods to treat your source water. Regardless of whether your water comes from your local municipality or from a well, make sure you know what is in your water.

 

pH

A pH reading is a measure of the free positively charged Hydrogen ions (H+) that are in a solution. The more H+ ions that are in the solution, the more acidic it will be. This will result in a lower pH reading. Conversely, the lower the amount of free H+ ions present, the higher the pH will be. High pH is not to be mistaken for high alkalinity. pH has a major influence on the availability of essential nutrients in the root zone and should be tested regularly. 

 

EC / Salinity

EC (electrical conductivity) is a measure of a solution’s ability to conduct electricity. This measurement is directly related to the overall concentration of ions available in the solution. The higher the EC, the more dissolved salts are present in the solution. However, this number does not tell you what ions are present or in what concentrations. 

 

Alkalinity

Alkalinity is the measure of water’s ability to neutralize acids and resist pH reduction. Carbonate and Bicarbonate ions of dissolved salts are the major constituents of alkalinity. This measurement will affect how much acid is required to change the pH of a solution. Because of this buffering effect, both pH and alkalinity need to be considered when making changes to your water and fertilizer program. High alkaline water sources will need to be neutralized with an acid to prevent unwanted rises in media pH over time. 

 

Hardness

A water’s hardness refers to the amount of calcium and magnesium present. Generally, source water with high amounts of calcium and magnesium will also have higher levels of bicarbonates and a higher alkalinity. However, it is possible to have hard water without high levels of alkalinity. 

 

Source Water Nutrient Content

Unless you are using an RO system (not recommended unless you must), your source water is likely to contain some levels of Calcium, Magnesium, Chlorine and other macro and microelements. Some ground water may contain high levels of calcium and/or magnesium and should be considered in the development of the nutrient program. Similarly, If high levels of microelements such as Boron are found to be in toxic amounts, filtration or site relocation may be required. 

 

  

 With a detailed water analysis in hand and all of these factors considered, you will be able to tell whether or not your water is fit for production or if pre-treatment and program alterations will be required. Do not guess when it comes to the quality of your source water. Make sure you know what’s in your water.