Brooke here:
A brief post today, with no pictures. The camera is somewhere under a pile of fish.
In my (airquote) spare time (/airquote) I’ve been looking for thinset and grout to replace the tile in the pool. I was on swim teams from elementary school until I left for college, and the memory of nine years of bleached hair and lizard-leather skin is something you carry with you when trying to repair a pool because thou shalt not disrespect chlorine and I didn’t think standard stock materials would last in that sort of environment.
While driving around last week, I saw a pool supply store and pulled a spontaneous right into the strip mall. I walked in and had one of those moments when you’ve reached for the glass of milk but grabbed the glass of juice by mistake, and your brain and mouth are derailed by the suddenness of not-milk. The suddenness of not-pool store would have been manageable had it been a real estate office or whatever, but hundreds and hundreds of Barbies in boxes piled to the ceiling and small, furious dogs barking at my ankles needed a few milliseconds to process.
As luck would have it, it was still a pool supply store, but the pool supplies were in a separate room. I spoke with a very nice older lady who promised to talk to her repairman and get back to me with the names of the products he uses to seat pool tile.
A few days later, she calls me back and asks if I have a pen. I do, and she says: “the tile goes in something called thinset. It’s a paste to hold tiles in place.”
It was a bad day anyway and I already had a stress headache, so I forged ahead. “Okay, and then you grout them in place using…”
“Grout.”
“Okay, thanks very much.”
And no, I cannot explain the Barbies.
Flying by night 
Is it just the look of the tile that you like?
When I was a kid, my folks had a pool redone in Florida, and the original coating had been done in marcite (I hope I’m spelling that right) so that may be something to look up. It was that scratchy sort of cement. I believe that’s what was used in the public pools as well. I’m *not* sure if they also used it as grout though. A search suggests that the grout used is a ‘waterproof epoxy grout’ that is then sealed after it sets- apparently the sealant is what protects it from the pool chemicals.
This site also advertises products for use in pools: http://www.recreonics.com/paint_sealants_patches.htm and sells a sealer to use over grout.
But the reason I ask, though- nowadays you can get pools redone with fiberglass mats, which is SO much less of a maintenance hassle, as the algae doesn’t stick as much. I honestly have no idea if that’s something you could lay yourself, though. I suspect the coating material requires special equipment, but it’s been almost twenty years since I saw it done, so…
But we want to keep the tile! There’s so few things original to the house that are worth preserving, and the tile is on it. It’s worth the time it will take to remove and reseat it to keep part of the original home.
That’s an awesome project, then. I wish you all the luck in the world 🙂
And I hope you find a sealant that fits your needs!
Clearly you have been hanging around with me too long, if you are regularly having random nonsensical interludes occurring in the course of normal sensible errands!