Microjet-based electrokinetic streaming current experiments were used to track changes at the surface of fused silica in the presence of ultra-dilute (<= 100 nM) acid and base solutions. These concentrations allow isolated study of the individual ions with minimal counter-ion interference. The observed changes in the streaming current upon exposure to these solutions demonstrate the first observed Hofmeister relationships at sub-micromolar concentrations, with a direct series observed relating to the absorption of cations and anions. Behavior of the divalent cations and chloride differ from the rest of the ions studied, which is attributed to multiple mechanisms of chemical interaction with the surface beyond adsorption. The presence of these Hofmeister trends at such dilute concentrations supports other work indicating changes in interfacial properties for mobile vs. stagnant liquid/solid interfaces.