Maintenance for micro-irrigation systems
Date: 08 Aug 2000 Author: Mike Robbins
Maintaining the micro jet irrigation
system on his Nashdale property is
a regular winter task for stone fruit
grower Robbie Armstrong
During winter, when a micro-irrigation system is not in use, water drains out of piping or accumulates in low parts of the system. Serious blockages can occur if the system is operated without a pre-season check and clean that has three key steps:
1. Clean the filters
Clean the whole filter, including the body or housing. Backflush sandfilters until they are completely clean. Carefully inspect self-cleaning filters for any failure or
holes in the mesh before placing them in the water supply.
2. Flush the system
Once the filters are cleaned and re-assembled, flush the system by turning on the water and opening the ends of mains, submains and laterals. In smaller systems, water will flow from each pipe. In large systems you will need to close the mains before water will flow from the submains, and perhaps to close the submains for water to flow from the laterals. Leave the end of each pipe open until clean water flows from it.
3. Chlorinate
After loose material has been flushed and all pipes closed off, inject chlorine at the pump at a rate to give 500 ppm concentration throughout the system. (Sodium hypochlorite is the most effective form of liquid chlorine.) After the chlorine has been distributed, shut the system off for 24 hours and give the chlorine time to break down any scale or sludge in the piping.
After 24 hours, turn on the pump and open the ends of laterals to flush out the dispersed sediment. Close the ends of laterals when the water runs clear.
The system is now clean and ready for regular use: note that periodic maintenance is essential to prevent a build-up of algae, slime and clay particles.