Water softener making municipal water too aggressive?

[Prism9208]

I have city water and my wife wanted a water softener installed to reduce hardwater stains on our plumbing fixtures. After confirming we had around 9-10 grains/gal, I installed a water softener. However, it is currently bypassed as I realized I needed to be more careful with respect to corrosion of my copper pipes with potentially more aggressive, softened water.

Test results from the lab (water softener bypassed):

pH = 7.0
Total Alkalinity = 110 mg CaCO3/L
Hardness = 157 mg CaCO3/L
Specific Conductance @ 25 °C = 731 umhos/cm

At-home tests (water softener bypassed):
pH = 7.5 to 7.75 from calibrated pH meter with ±0.1 uncertainty, measured at 20 °C
Hardness = 10 grains/gal from Hach 5-B

When I play around with some Langelier Saturation or Ryznar index calculators, I see my tap water is balanced with respective to corrosive or scaling risks. How can I deploy a water softener without going too aggressive within copper lines? For example, if I simply reduce my hardness to 4 grains/gal (guess value) in these calculators while holding all else equal, I fall to a -0.4 LSI and become slightly corrosive.

Is this a scenario where if I want to remove the hardness I need to boost the pH/alkalinity to stay balanced?

Full water test results:

Turbidity = 0.40 NTU
Calcium = 48.6 mg/L
Copper = 0.044 mg/L
Iron = 0.010 mg/L
Magnesium = 8.7 mg/L
Manganese < 0.004 mg/L
Potassium = 3.9 mg/L
Sodium = 68.8 mg/L
Arsenic < 0.001 mg/L
Lead < 0.001 mg/L
Chloride = 129 mg/L
Fluoride = 0.2 mg/L
Nitrate as N = 1.19 mg/L
Nitrite as N < 0.02 mg/L
Sulfate = 22.9 mg/L
Sediment: Absent
Color, apparent = 0 CU
Odor = 3 T.O.N.
Total Alkalinity = 110 mg CaCO3/L
Hardness (calc.) = 157 mg CaCO3/L
Specific conductance @ 25 °C = 731 umhos/cm
Residual Free Chlorine = 0.59 mg/L
pH at 25 °C = 7.0
Ammonia as N < 0.1 mg/L
Coliform Bacteria: Absent
E. coli Bacteria: Absent

 

[ditttohead]

I have city water and my wife wanted a water softener installed to reduce hardwater stains on our plumbing fixtures. After confirming we had around 9-10 grains/gal, I installed a water softener. However, it is currently bypassed as I realized I needed to be more careful with respect to corrosion of my copper pipes with potentially more aggressive, softened water.

Test results from the lab (water softener bypassed):

pH = 7.0
Total Alkalinity = 110 mg CaCO3/L
Hardness = 157 mg CaCO3/L
Specific Conductance @ 25 °C = 731 umhos/cm

At-home tests (water softener bypassed):
pH = 7.5 to 7.75 from calibrated pH meter with ±0.1 uncertainty, measured at 20 °C
Hardness = 10 grains/gal from Hach 5-B

When I play around with some Langelier Saturation or Ryznar index calculators, I see my tap water is balanced with respective to corrosive or scaling risks. How can I deploy a water softener without going too aggressive within copper lines? For example, if I simply reduce my hardness to 4 grains/gal (guess value) in these calculators while holding all else equal, I fall to a -0.4 LSI and become slightly corrosive.

Is this a scenario where if I want to remove the hardness I need to boost the pH/alkalinity to stay balanced?

Full water test results:

LSI, CI etc. are algorithmic estimations... in general a softener will not have any negative affect on the copper plumbing. You could simply monitor the water over the next year and test for copper before and after the softener. Copper damage is a very long and slow process.

 

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[Prism9208]

LSI, CI etc. are algorithmic estimations... in general a softener will not have any negative affect on the copper plumbing. You could simply monitor the water over the next year and test for copper before and after the softener. Copper damage is a very long and slow process.

Thanks for the feedback. I agree overall about the long time scales of copper corrosion. I guess in this case I'm more concerned about the near term copper/lead leaching for consumption/health concerns if I'm not achieving the appropriate water chemistry.

 

[Reach4]

Some run unsoftened water to the kitchen cold.