Unfortunately many growers don’t monitor the output of their irrigation system on a daily basis. It’s should be a standard procedure to measure the actual quantity, EC and pH of irrigation water in different sections of the greenhouse. Without notice a water hammer while closing the irrigation valve or during flushing the irrigation pipes, drippers might be opened.
A water hammer that can “restart” some drippers after closing. Flushing without opening the drippers just works at a working pressure under 1 bar. In case the working pressure is at 2 – 3 bar, the first drippers on the irrigation line will open because the pressure is higher than the required 1 bar en won’t stop before the pressure falls down below 0.2 bar. An unpleasant surprise for your crop too.
Furthermore the industry should demand that the right EC, pH or chemicals are available for every single plant at the same time. Hence, a closed circuit has to become the standard on every nursery. Current practice is that after sometimes 6 irrigations the desired solution will arrive at the plant. In case of an e.g. EC reduction according to radiation levels, such a strategy fails completely.
Be aware of possible damage to the diaphragm of your drippers due to chlorine gas in the system as a result of a chemical reaction in case of Chlorine disinfection at low pH levels (< 5).
Because of desired acid conditions for appropriate desinfection (UV) the pH in the clean water tank storage falls easily down towards 3.5. The first valve that will be irrigated in the morning suffers from this low pH: both plants and drippers.