How to remove salt crystals & then protect bluestone around salt water pool

by Cliff McClinton
(Gadsden, AL USA)

We have a perimeter overflow pool with bluestone coping that has water flowing over it constantly. We have had no issues with this coping as it is not subject to wet / dry cycle and constantly stays wet. The Pennsylvania bluestone natural cleft squares that surround the pool is a nightmare. The stone has changed to a much lighter shade and appears to have delaminated in places. It was installed over a ooncrete base. The stone was never sealed Due to the overflow design of the pool saltwater always saturates the patio when we swim and when it rains.

1> What can we do to removed the salt crystals on the grout lines & and clean the stone so that it returns to its original darker blue color? The squares are darker in the middle and get progressively lighter around the edges. We have pressure washed the surface of the stone previously but this does not remove the crystals.

2> Should the top of the stone be sealed at this time? I have read many differing opinions on this from sealing all 4 sides of the stone and edges before installation to NEVER seal the stone as it will trap the salt into the stone.

3> What professionals handle this type of repair?