Yes, it should be fine at 100ppm.
I have bought one of these units and my only reservation as others have pointed out, is that you must hook up a proper ammeter to the output, as the unit PSU meters are not very accurate, although the Constant Current circuit is perfectly adequate.
My first two batches of Cinnamon-capped colloidal silver turned out perfectly. Thanks for pointing me in the direction of this unit. I use Silvertrons for unattended production or for extremely accurate production, but for my own casual use where the ppm can be within 1-2 ppm of the desired endpoint, this is fine. If one is making 40 ppm as I normally do, the difference between 38-42 ppm is not a particular concern, as I normally let it run a bit longer anyway.
An excellent unit, and I commend it to anyone who wishes to buy a laboratory PSU.