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Itā??s extremely difficult to determine if something in the water supply is causing plant growth problems. Root rot pathogens may originate in water, but they can come from a number of sources, including fungal spores, blown in dust or brought in by insects. Mineral problems can be a little easier to trace if the water supply analysis is available to check levels of elements. Plant problems which may be caused by water treatment chemicals are difficult to diagnose as some plants are much more sensitive than others and the type of system also plays a role. Research studies have reported that chloramines in hydroponic nutrient solutions can cause growth inhibition and root browning in susceptible plants. One study reported that the critical chloramines amount at which lettuce plant growth was significantly inhibited was 0.18 mg Cl/g root fresh weight, however, the levels at which some other species would be damaged is as yet undetermined. Similar problems exist with the use of other water treatment chemicals; chlorine and hydrogen peroxide are good disinfection agents, but too much in the hydroponic nutrient will cause root damage and just what is a safe level is dependant on a number factors such as the level of organic loading in the system.