Figure 6. A short section of new plastic tubing "inserted" into an irrigation lateral can serve as a scaling indicator. After sufficient water has passed through the line, the insert can be removed and cut open to observe newly-deposited scale (inset). The amount, type, and rate of scale deposition occurring on the tubing wall can help determine the scaling potential of the irrigation water and the effect of injected scale-inhibiting chemicals. The effect of an injected purge chemical can be evaluated by installing a section of scaled tubing prior to treatment and observing the inside walls following system flushing.