Minor repairs should always be done before the uniformity testing is done. Go over the inspection sheet to find the list of items that required attention. Refer to Section 3.0 for more maintenance ideas.
Minor repairs should be done
Unclog nozzles and emitters.
Flush filters and replace damaged screens and discs. Replace sand/media in a sand filter if it is very dirty.
Flush pipelines at the end of a season and occasionally during the growing season to remove sediments from the lines. With a little experience the frequency for doing this will become known. Water soluble matter and micro-particles pass through the filter and deposit in the pipelines. Surface water may contain more of these particles. Micro-irrigation systems require the drip lines to be flushed to avoid the emitters from clogging.
Treat emitters with chemicals as needed to remove deposits.
When flushing, open the end of one lateral at a time so the water flows faster in that line to pick up and move any particles.
Low, tilted and plugged heads
Get risers back up to a vertical position and clean out plugged heads. The top of the sprinkler head should be nearly at or parallel to grade. On level ground an acceptable tilt should be less than 5 degrees. On a grade the best performance will be achieved by setting the head at half the grade of the surrounding slope; thus on a 12 degree slope the tilt will be set to 6 degrees.
Replace non-matched heads
Replace any non-matched sprinkler heads or nozzles.