Taking the accepted formulation of 1 litre of water/1 kilo of sugar and 
35 grammes of Oxalic di-hydrate to prepare a varroa controlling mixture, 
I was wondering the following:

Will the quality of the water influence the ability of the acid to do 
its dirty deed ?

The water from my well is loaded with dissolved mineral material - 
Saline surface deposits cause problems in damp areas that dry out on the 
summer months. Local farmers have had to plant alkaline resistant 
grasses and other tolerant plants on many areas to ensure some 
vegetative cover.
We have shale as the bed rock (and it is the aquifer) with over burden 
of glacial derived till - again shale based with other material.

Peter

******************************************************
* Full guidelines for BEE-L posting are at:          *
* http://www.honeybeeworld.com/bee-l/guidelines.htm  *
******************************************************