A very common and often underestimated, or even overlooked, problem is the quality control of water used for irrigation, fertigation or pesticide treatments. 
Often, the water used in agriculture has a high lime content and excessive electrical conductivity, which can cause complications during the production cycle (e.g. difficulty in maintaining a constant pH in the substrate, increased EC of the substrate, reduced fertiliser efficiency, inertisation of active ingredients and reduced effectiveness of treatments).   
A common practice to contain the problem is to use acidifying products (strong acids, mainly nitric acid) to regulate the pH and prevent the salts dissolved in the water from becoming insoluble and precipitating. 
However, the problem is only partially solved and once the treated water reaches the substrate, calcium and other cations still accumulate.
Sun water improver has weak acid properties, neutralises carbonates and bicarbonates, but at the same time complexes the salts present in the water (e.g. calcium, magnesium, iron, etc.), preventing their precipitation and keeping them available for root absorption.The effect of the application is to stabilise the pH of the substrate, increase nutrient absorption by the crop and, consequently, reduce the amount of fertiliser required.
The product can be used systematically, i.e. by adding it to each irrigation. 
This is the most common method, but it is also possible to use it occasionally, increasing the dose.
In this case, the effect of osmotic regeneration of the growing substrate is obtained, promoting the mobilisation and leaching of excess salts.