White hard Gooey subsatnce and iron looking stains on tile.

[CVAL44]

I am getting stains on my tile underneath the natural Stone. Some of the stains look like iron but there is also a hard white substance that I can't remove. Pool is only 90 days old

 

[ajw22]

You have iron leaching from the stone in addition to Efflorescence - Further Reading

What is on the other side of the stone?

 

[CVAL44]

You have iron leaching from the stone in addition to Efflorescence - Further Reading

What is on the other side of the stone?

The spa spillover and nothing behind the rock waterfall