I need some help in reducing or eliminating the amount of background silver precipitate on the slide when performing a Bielchowsky stain. The method being used is a 20 % silver nitrate solution for 20 mins followed by a 15 min incubation (in the dark) of ammoniacal silver.  The reducer consisting of citric acid, formaldehyde, water.  A few drops of the reducer is added to the ammoniacal silver and checked microscopically until fibers are seen.  At the same time the fibers are being developed the excess background precipitate is forming.    Any suggestions or solutions would be greatly appreciated.