This is another example why you should not seal swimming pool tile.  We salt blasted the calcium line off with no problems only to discover the mess shown in the photo.  One of our competitors cleaned the pool tile in the past and reassured the home owner that sealing pool tile will prevent future build up and protect the pool tile from the water.  Well once again, they were wrong. Sealed swimming pool tile will look nice for a short time but the UV in the sun will turn the sealer cloudy and permanently ruin the look of the pool tile.  Originally this pool tile was a semi-gloss glazed finish now its dull and cloudy.  Excess sealer ran down the Pebble Tec staining it too.  Not shown in this photo but there was also sealer dripped around the floor of the swimming pool interior as well.  Homeowner noticed this and could not figure where the stains came from.  Mystery solved….Arizona Bead Blasting does NOT SEAL swimming pool tile, Pebble Tec or stone.  Our custom calcium removal equipment does not damage any glazed or natural surface.  Thanks Garry for your business!  We shall see you in a few years. – Arizona Bead Blasting Team.