Once the supply water has been tested, you need to determine if and how the water needs to be preconditioned before use. Ideally the first water tests should be done prior to construction so that the proper conditioning equipment and holding tanks can be designed into the irrigation system. There are different ways of preconditioning the water.
Filtering – Filtering irrigation water is essential to maintain the health of plants, protect irrigation equipment, and ensure efficient nutrient delivery. At its minimum, unfiltered water can contain sand, silt, organic debris, algae, and pathogens, which may clog drip emitters and sprinklers or introduce diseases to crops. It can also cause wear and tear on pumps and valves, leading to costly maintenance. Additionally, filtering is especially important when using surface or reclaimed water, which often contains more contaminants than groundwater. By removing these impurities, filtration helps ensure consistent water flow, better plant growth, and longer-lasting irrigation systems.
Disinfection – UV disinfection is used in irrigation systems to ensure that the water used is free from harmful microorganisms that can damage crops. Ultraviolet (UV) light effectively kills or inactivates bacteria, viruses, fungi, and algae by disrupting their DNA, preventing them from reproducing. This is especially important in systems using recycled, surface, or untreated water, which often contain high microbial loads. The Priva Vialux UV system is specifically designed for treating irrigation water.
Temperature control –. Irrigating with low-temperature water can pose several challenges for plant health and growth. Cold water can shock plant roots, especially in warm weather, leading to stress that slows growth and reduces nutrient uptake. This temperature shock can also disrupt cellular processes, causing wilting or stunted development. Additionally, cold water lowers soil temperature, which in turn reduces the activity of beneficial soil microbes that are essential for nutrient cycling. This can make nutrients less available to plants, even in well-fertilized soils. For young plants and seedlings, cold irrigation water can delay germination and early growth, which are critical stages for establishing a healthy crop.
Bicarbonate control – We have been talking about the importance of nutrients to the plants. These nutrients are only useful if they can be taken up by the plants. Nutrient update is heavily influenced by the pH level of the irrigation water. If the pH level ois too high, it will adversely affect the update of nutrients such as zinc, boron, iron, and copper and conversely, if the pH level of the water is too low, it will adversely affect the uptake of nutrients such as nitrogen, potassium, phosphorus and calcium. An optimum pH level will be part of your plant recipe.
The bicarbonate (HCO3) level of your irrigation water is critical in order to maintain an optimum pH level. This is because bicarbonate acts as a buffer, resisting changes in pH. An optimum bicarbonate level is between 0.10 mmol/l and 0.50 mmol/l. If the bicarbonate level is too high and you try to lower the pH level by using acids or acid-forming fertilizers, the presence of excess bicarbonate will neutralize those efforts, making it difficult or impossible to achieve and maintain the desired pH range. In soils, high bicarbonate levels can also lead to alkaline conditions, which reduce the availability of key nutrients like iron, zinc, and phosphorus.
High bicarbonate levels often occur in water that comes from wells or aquifers in regions with limestone or chalk or in arid regions where evaporation concentrates dissolved minerals.
If your bicarbonate levels are too high, they can lowered using a Priva Neutralizer, which mixes acid with the supply water. This acid reacts with the supply water over time, converting the HCO3 to CO2 which is then released into the atmosphere.
Low bicarbonate level often occur in rain water or water that comes reverse osmosis systems.
If the bicarbonate levels are too low, bicarbonates need to be added to the irrigation water.
Other contaminants – If the water supply is too contaminated, you may need to use reverse osmosis (RO) systems to remove unwanted salts, minerals, and other chemical contaminants. RO-treated water provides a highly purified source that can be tailored to meet specific crop requirements, especially in sensitive cultivation systems such as hydroponics or when managing salinity in soil. When using RO water, the bicarbonate level will be too low and bicarbonates will need to be added prior to use in order to allow for a proper pH control.