Star-San and concrete?

I have "vintage" concrete washtubs in my basement where I usually clean up fermenters/kegs and used star-san for the first time down there. After I dumped out the keg of star-san i wondered if the acid would do anything to the washtubs, acid etching, muriatic acid cleaning and all. It is a pretty weak mixture but just want to be sure it won't harm them.

I know, don't fear the foam.

I bet it would etch the concrete if the concentration was high enough, but not 1oz in 5 gallons.

Compared to muriatic acid your starsan if diluted is a very weak acid. Any etching it might be doing is taking place on a very microscopic level but Im sure over the course of several years you might notice the surface getting a little rougher. Its not something thats going to eat your tubs though.

If youre rinsing it off right away your 'damage' is going to be even less because there is really reduced contact time which acid needs to react with the basic nature of the concrete.

To be extra safe you could spray it down with a solution of baking soda and water at a rate of 1/2lb baking soda to 5 gallons of water which is the standard for neutralizing a 10:1 mix of muriatic acid after etching a floor/drive/garage.