Water conditioners are used in areas of hard water, but what function do they perform?
A characteristic of hard water is the high proportion of charged cations (dissolved minerals) that affect the performance of agrochemicals by locking up a proportion of its active ingredients. Water conditioners address this by effectively negating the effect of the cations before the agrochemical is added.
Water conditioners do not directly enhance the performance of an agrochemical, but by improving the properties of water they allow the active ingredient to perform as it is expected to do so.
Glyphosate is a commonly used herbicide, the performance of which is known to be adversely affected by hard water. Glyphosate binds with the cations in the water to form a strong complex which is not bio-available. Only the remaining unbound glyphosate is fully available to act as a herbicide.
Where a water conditioner is not used its performance can be impaired as a result.
In independent trials, the effectiveness of Roundup Ace when mixed with a hard water containing 380 parts per million (ppm) of CaC03 was found to be improved when the water conditioner X-Change was added.
In addition to addressing the cation imbalance, X-Change offers other beneficial properties.
The pH of the spray solution can also affect chemical efficacy. Spray solutions with a high alkaline score will promote alkaline hydrolysis – where the molecules in the active solution become deactivated – by adding X-Change into the tank first, ahead of the agrochemical the pH is reduced to around 4.6 preventing hydrolysis from occurring.
Alkaline degradation of pesticides is almost always associated with hard water. Many pesticides are less stable in alkaline solution and perhaps the best known example of this is dimethoate. Within 1 hour at pH 9 losses of up to 50% of the active dimethoate originally added to the spray tank are possible.
Speed of hydrolysis measured by half-life (time taken for 50% of product to be hydrolysed)
A third function of a water conditioner, such as X-Change is its humectant properties. Humectancy reduces the rate of chemical crystallisation by slowing the drying process. This gives the plant more time to absorb the active chemical while a hydration sheath prevents surface run-off.