Testing water for total soluble salts
Samples should be at least 500mL in a clear glass or plastic bottle, previously well rinsed with the water to be sampled. Use a clean, screw cap, cork or stopper to seal the bottle, and mark the bottle itself with the sender’s name and address, and the date of sampling.
Total solids in reticulation water
High levels of total solids such as clay or silt in water can cause problems including blocked nozzles and filters, excessive wear of pumps and nozzles, and adsorption of chemical molecules. This tie-up of chemicals, particularly by suspended clay particles, will reduce the effectiveness of some pesticides.
pH and alkalinity
Excessively acid or alkaline water may affect the uptake of nutrients by plants. It also may reduce the performance of some pesticides and damage the reticulation system. The acidity or basicity of reticulation water is expressed as pH (< 7.0 acidic; > 7.0 basic). The normal pH range for reticulation water is from 6.5 to 8.4.
Many underground waters contain iron. Water containing iron in solution may be clear and colourless when first drawn, but becomes cloudy and eventually deposits reddish-brown hydrated iron oxide after standing in contact with the air. Iron in water stains clothes, buildings and pathways brown when used in sprinklers on nearby gardens. This can be a problem with sprinkler usage on fruit trees and nursery plants. Iron deposits may block trickle systems. There is no simple method of removing iron, so garden sprinklers should be sited to prevent spraying buildings and places where the stain might be conspicuous.
In arid areas excess boron may be a problem in the garden. If the water supply is considered suitable for the garden, yet beans, radish and citrus suffer, a check for boron is advisable.