Erosion

[RussellC]

I bought a house recently with an SWG pool. I am noticing some sand in the pool from the rocks where the water feature is. Is this salt erosion? Do I need to seal this rock? The flagstone coping is fine but there is a little white scale like stuff at the sides of the spillover. The pool is about 9 years old. Thanks for the help. Here is a picture:

 

[gwegan]

Most likely calcium deposits. could you post complete test results?

 

[atttech-2]

Sealing the stone is not a bad idea can't hurt and may help no way to know for sure if it's from the rock or just blown in stuff.

I would not read too much into where you see it pooling sand and dirt will tend to collect near corners and on the outer edges of powerful water flows my pool gets visible collections where the baja shelf meats the pool floor and a couple of feet out from where the sheer falls.

 

[RussellC]

Thanks y'all. When I took possession of the house the readings were:

FC - 3
CC - .5
CYA - 50
CH - 175
TA - 160
PH - 8.2
Salt - 3200

Now after:

FC - 9
CC - 0
Ph - 7.5
CYA - 80
CH - 425
TA - 90
Salt - 3200

 

[gwegan]

So you chemistry is OK. I suspect its just dirt that blows onto the shelf when the water is not running wne the spa overfills it runs it into the pool.. If you have a robot or cleaner in the pool usually?

In Austin sealing the stone could only help.