Lythic Densifier, made with colloidal silica, is efficient, profitable, and sustainable. Spray-applied, it does not have to be scrubbed in. Lythic reacts while the slab dries—usually in one hour. There is no wet residue, scrub-off, or disposal. It eliminates the risk of whitening and cannot be over-applied. Lythic Solutions Inc. 360-694-5347. www.lythic.net