Anyone have any good methods for making large quantities of 20 ppm CS?  I
would like to be able to produce at least 3 or 4 gallons an hour.  LVDC I
believe would be too slow.

Marshall,

I have two of Trem’s SG-7 units and using both I can produce 10 gallons of
25 ppm EIS in approximately 7 hrs.  Ten gallons of 20 ppm could be produced
in 4 to 5 hrs.  In the past I have produced 20 gallons of 25 ppm EIS in one
day.
You could buy a 30 or 55 gallon poly (HDPE) drum, use two SG-7 electrode
setups and a strong submersible fountain pump (
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46208 ) for
stirring.  I haven’t tried a setup like this yet, but plan on experimenting
sometime in the near future.  You may want to talk to Trem (1-877-745-8374),
he would know more on whether a setup like that would work or be practical.

I have made approx. 50 ppm (55uS), clear to very pale yellow EIS with this
unit adjusted for no shut off, although it takes about 16 hours to produce 2
gallons.

The only other large volume unit I have seen on the market is this one,
http://colloidalsilverresearch.com/coll50.htm
They claim 50 gallons/day of 5 ppm, using my production numbers with the
SG-7 may equate to only 20 to 25 gallons of 20 ppm per day (if it will run
the concentration that high) and they want $4000 for that unit.

Hope this helps,

Chuck