The main factors influencing water quality for plant growth are pH, salinity, iron and sulfite content, chlorination, and biological contaminants.

    pH (potential Hydrogen) is a scale ranging from 1 to 14 that measures acid/alkaline balance.  A pH of 7 is neutral, a pH below 7.0 is acidic and a pH above 7.0 is alkaline.  Most plants prefer a slightly acidic solution(5.8-6.5).

    Salinity, measured in ppm(parts per million) or EC(Electrical Conductivity), refers to the dissolved solids in the water.  EC and ppm meters measure the total dissolved solids and does not break down and reveal the separate minerals that read on the meter.  The most common and easy way to measure dissolved solids is EC.

    Most municipal water supplies have a slightly alkaline pH and a low, stable EC and are suitable for plant growth.

    In some rural areas, and some coastal area municipal water supplies, have significant levels of iron and sulfite that can bind essential minerals  present in the nutrient solution.  It is not suggested to use softened water with plants as those salts used to soften the water also bind other minerals.

    Chlorination of municipal water supplies usually does not pose a problem.  If chlorine is a concern, most of the chlorine can be removed by simply aerating standing water overnight before use.

    Pathogens and diseases can also be present in the water supply.  Even municipal water supplies can carry plant diseases  because the water supply is usually treated for contaminants that affect humans not plants.   Using fungicide preventatives such as potassium silicate or beneficial bacteria helps to combat the onset of fungus and diseases.

    Hint:  Keep a close watch on pH and EC.  Change the reservoir every 4-5 days.  A regular reservoir change will keep pH, EC levels consistent and ensure fresher water is available to the plants!