New Water Heater - Scale, High pH / Alkalinity

[DumbOnPlumbing]

We moved into new construction 9/1. We have plastic tube PEX plumbing.

Recently had the control on our Bradford White replaced and at that time our new plumber took a look at the rods in the tank with a camera. He was amazed they had a lot of scale (looks like calcium) on them already. I have also noticed a little white flaky scale on the shower control handles. He flushed the system and said he would come back in a few months and replace the rods.

We know the hot water heater is new from the manufacturer date.

I also know that our water test from a pool company showed a high pH of 7.8 and the ideal is 7.4-7.6. Our total hardness is 4. I ran other at home water tests and there is nothing out of range for nitrates, copper, iron, etc.

We do use a Fleck 5600SXT water softener which was installed shortly after the hot water heater.

Do you think the scale is from high alkalinity? Anything I can do about the scale build up? Maybe flushing the tank and replacing the rods in a few months is the best I can do.

 

[Reach4]

An anode changes as it does its job of protecting the water heater. I don't know what the expected appearance would be after 5 months, but I could see the white deposit-looking material, that will totally displace the metallic magnesium or aluminum in several years, appearing on the surface in 5 months.

Some people believe in replacing WH anodes, and others do not. If somebody is to replace the anode later, I suspect it could be a good idea to loosen the threads a bit earlier in life. It takes an impact wrench to remove later, but I don't know for sure that it is that much easier early. I have a powered anode, which does not get consumed.

7.8 pH is certainly in the ideal range for household use. Maybe not for a pool, but then the pH of a pool is going to be changed by chlorine, or other disinfectant, anyway.

There is a factor called the Corrosivity ( Langelier or Ryznar ) index that would be good for measuring whether a water tends toward being corrosive or tending to leave deposits.

 

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[Smooky]

If the water softener is sized correctly, it should remove the hardness/scale. Was the test you did on the treated water or raw water?

 

[DumbOnPlumbing]

Thanks Reach 4. Where does one get the Corrosivity ( Langelier or Ryznar ) test?

 

[DumbOnPlumbing]

Thanks Smooky.

The softened water was 7.8 with total hardness at 4.
The unsoftened was 7.6 with total hardness at 395.

 

[Reach4]

That is often part of a lab water test including kit 90 from http://www.karlabs.com/watertestkit/

I expect your anode is in good condition. While a lab water test on well water is good idea, don't take the anode appearance as an indicator that you need a water test.

I also presume you are saying your softened water has 4 ppm hardness rather than 4 grains. That is good.

 

[DumbOnPlumbing]

Fairly certain it's ppm because there was some equation you have to do to figure it out. Plus the report for the softened waters says the total hardness is low.