Mineral drop out

kdietz

Member
Jun 28, 2010
8
Weatherford, Texas
I'm getting a scattering of white granules on the bottom of my salt water pool. I was told it was mineral drop out and it will go away on it's on.

What causes this and is there a chemical treatment?
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,475
SW Indiana
Welcome to TFP.

More than likely it's calcium. Post a full set of test results and you'll get better advice.
 

Poolsean

TFP Expert
Apr 15, 2007
1,462
Ft Lauderdale, Florida
As a manufacturer of the Pool Pilot salt chlorine generator, I have never heard the line "Mineral Drop Out", so that's a new one on me, although not technically wrong.

"Minerals range in composition from pure elements and simple salts to very complex silicates with thousands of known forms..." from Wikipedia

What does the white stuff look like? Flakes? John is probably correct though. Most minerals will stay dissolved in water. The most common pool related mineral is calcium, which can form a solid in water.
 

kdietz

Member
Jun 28, 2010
8
Weatherford, Texas
That's the term my Pool service company used when I asked about the white granules on the bottom.

They are kind of flakey...looks like salt before it completely dissolves.

I'll run some tests this afternoon and report back.
 

Poolsean

TFP Expert
Apr 15, 2007
1,462
Ft Lauderdale, Florida
With hot water temperatures, your water balance is slightly scale forming, and can result in the cell staying clean because the calcium scale is breaking off the cell in flakes and blowing back to the pool, instead of building up thick enough to clog the cell.
You can either drain down some water to lower the calcium hardness, or maintain your pH at a lower level, 7.4 is good.
 

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