Bought one of those motorized magnetic base stirer for CS. Bought the  
plastic button for stirring  small batches. I also got what looks like  a 
roller 
bearing and some plastic tubing. Tubing was approx 2 1/2 to 3 inches  long, by 
putting metal bearing in end it swings a big arc
in my gallon jar. I love it and highly recommend the stirer for  keeping all 
batches stir ed which
helps keep particle size small. Since I had over done it before (gray face)  
I am taking Selenium and keeping PPM down to 2 on TDS which is provably around 
4  PPM. Face did lighten up but feel rest will just take a longer time.
Bob