Calling all tile experts! We recently had slate tiles installed in our shower and sealed the tile and grout with Aquamix penetrating stone sealer. After waiting a week to make sure the shower was good and dry, we started to use the shower. in 3-5 days we started to get a "halo" effect showing up around the perimeter of the tile. so we quit using the shower. I thought maybe it's not sealed enough (even though the water beaded up when used) so I resealed around the grout and the areas that were turning light. Then I waited another week then started to used the shower again. in another 3-5 days even more of the tiles started to turn. So again we quit using the shower. Now it's been over 2 months and even without use, each week there seems to be more and more tiles that start to bleach out and get a halo around them. I've been to several tile stores asking how to fix, why it happened etc. no one knows! I've tried stone cleaner, stripper, different sealer nothing works. So I'm quite irritated to say the least since we spent over $2500 on a shower we can't even use. (Well I guess we can use it but I'm afraid to in case it gets worse.) Also, I'm trying to figure out who is at fault (the installer, the tile company, the grout company, the sealer company??? in case it has to be ripped out and replaced. I'm not going to pay for that myself! Any ideas of how it could have happened and what to do about it would be greatly appreciated!