Product review (4 stars): recommended by installer
My old Dampp-Chaser of 25 or so years died last year. It really kept my piano in good shape, so I decided to replace it (costly thing that it was). Installer recommended I continue with distilled water, but to add a capful of this stuff to each bucket when I refill.
BTW: Dampp-Chaser is an excellent product. After the new unit was installed, I had a complete thorough cleaning and tuning of my Kawai small grand, and it sounds bee-oo-tee-ful! Come to think of it, piano is probably closer to 28+ years, since I bought it used at 1-2 years old and had the D-C put in at that time (not knowing a thing about it, although I did add water when needed). 28 years is considered old for a piano. But my baby still sounds great.