> Information in english on the German field trials can be found at:- > http://www.mellifera.de/engl2.htm > http://www.apis.admin.ch/english/host/pdf/alternativ/absOSRalph.pdf I did some research. Univar sells tech grade oxalic acid in 25kg quantities. It is a stock item and costs $4.18/kg (CAD) for tech grade, which has a stated minimum purity of 99.6% Chemfax has 1kg, 5kg, and 22.7 pails for $16.50, $62.10, $165.40. Again, it is tech grade. Lab grade and reagent grade are also available, but at much higher cost. If the web site (above) is right and one treatment takes is 2.8g, then 25kg would treat (25,000 / 2.8 = ) 8,929 colonies once for a total material cost of $104.50 CAD or $66 US (plus labour). The material cost amounts to about a cent per colony per treatment. That's cheap! allen http://www.internode.net/honeybee/diary/