Water may still temporarily darken it with some grouts. Sealer doesn't make it waterproof...just makes stains harder to "set."

One coat may be OK....I generally do a second one a day or two later. Re-seal it every 8-12 months.

Thanks StoneTech. My tile guy did such a beautiful job and I want to take good care of it. He's laying floor tile at this moment, so in a few days I'll redo the shower and then the floor.

It's such a relief and joy to have such quality work.