star san precipitates white sludge

[CBelli]

Does anyone else notice a white material that precipitates out of star san over 3-4 days?

I have a plastic bowl that sits in 1/2 of my double bar sink... I generally fill it with star san on kegging day to hold all the little bits that I use in my pressure transfer. After a few days I notice this white film/sludge at the bottom of the bowl....

any thoughts?

my water is pretty common
PH 7.7
Dissolved Solids (TDS) Est, ppm 336
Electrical Conductivity, mmho/cm 0.56
Cations / Anions, me/L 5.7 / 5.7
Sodium, Na 29 ppm
Potassium, K 1 ppm
Calcium, Ca 55 ppm
Magnesium, Mg 20 ppm
Total Hardness, CaCO3 221 ppm
Nitrate, NO3-N 1.8 ppm (SAFE)
Sulfate, SO4-S 12 ppm
Chloride, Cl 95 ppm
Carbonate, CO3 < 1 ppm
Bicarbonate, HCO3 126 ppm
Total Alkalinity, CaCO3 103 ppm

 

[PeteNMA]

It's not star San per se, it's your water. The chemicals in the star San are precipitating out with some of the dissolved solids in your water. Make it up with RO or DI water from the grocery store and you won't have that issue

 

[IslandLizard]

Yep!

Now my water is a lot softer than yours, and I see it too, after a week or 2. Hoses that lay on the bottom also get that residue/sludge on the inside, but it brushes out easily. If I let the bucket sit for a few weeks, I siphon the clear Starsan off the drab on the bottom. Still works as intended.

Something in the Starsan must be sequestering the minerals, perhaps EDTA.

 

[CBelli]

Thanks for the input

 

[mabrungard]

StarSan reacts with the calcium in your water, which creates the precipitate you see. That creates a slimely layer on any equipment you leave in the solution for long. It is best to use something like RO or distilled water to make StarSan solutions. If you have a water softener, you could also use that water since it doesn't have any calcium either.

Without calcium, StarSan solution will last a long time when in a sealed container.