Can using tap water to make a 1% solution of Alconox cause there to be some undissolved Alconox particles?
Yes, it is possible that the tap water is very hard water and the undissolved Alconox particles being observed are actually white precipitates of calcium and magnesium carbonate. In extremely hard water (water that is very high in calcium and magnesium content) it would even be recommended to use as high as a 1.3% concentration. This would assure that there is sufficient chelating agent present to tie up the calcium and magnesium to avoid formation of insoluble precipitates of calcium and magnesium. If the problem is hard water, then Alconox recommends using a 1.3% solution of Alconox (390 grams of Alconox +/- 15 grams of Alconox) in 30 L. It may take more than 2 minutes to dissolve, because first the insoluble carbonates are formed, and then the chelating and sequestering agents work on these to react with the calcium and magnesium and eventually the carbonates go back in to solution. It could take as much as 4 minutes. Another solution would be to use softened water, purified water, or to simply dilute the hard water 50/50 with softened or purified water instead of using just hard tap water for the 30 L solution.
To view the technical bulletin for Alconox, Powdered Precision Cleaner please visit http://www.alconox.com/downloads/pdf/techbull_alconox.pdf.