Is it normal to have salt build up on pool wall under spa spill over in a SWG pool?

I have been wondering about this problem for a while now.

Under the spa spill over I have a white crusty stuff build up. Its on both sides of, and under, where the water spills over the spa ledge and runs from the upper spa height to water level. I tried cleaning with diluted muriatic acid thinking it was calcium build up but it didn't come off nicely. I saw some fizzing but not a lot.

That leave salt build up. Is it possible or normal to have salt build up on a SWG pool?
I know the salt levels are normal range (3000-3500 ppm) as my intelliChlor unit reports the salt levels.

What type of surface do you have? If it's stone, it might just be effervescence.

It is concrete in-ground pool with tile under the spa spill over (I need to take and post a picture of the front spill over view).

Speaking of effervescence, I do have an issue with that on some of the bricks on the top edge of the spa. The brick used for the top ledge/seat has effervescence showing through the grout joints. You can see some of the damage along the top edge of the tile just under the brick and also in the brick grout joint http://i921.photobucket.com/albums/a.../Spaissue2.jpg