Lime Deposit?

Need help diagnosing this deposit on the water line.

Well water
Hot water heater Hot side
Copper pipe

Is the deposit build up from a previous leak?

Is the deposit on the copper pipe Salt, Calcium, or Lime?

Not an active leak during the inspection.

does it really matter what it is? it needs repair…

Agree.

Could it be from dissimilar metal causing electrolysis?

It matters to me as I would like to be more intelligent than any of my clients that ask me “What is this?”.

I’m not sure, but don’t think so as this particular line is all copper.

What would be an appropriate narrative for this issue???

It probably started out as a pinhole leak which ran down the pipe and built up through the years.
It look like the stalactites formed from a drip from above.

Just a guess.

Just curious is the electronic ground hooked up nearby ?

That would be my guess also. Coming from the electric hot water heater I couldn’t remember if it was a calcium or lime that builds up in most electric hot water heaters.

Sorry, I don’t recall a ground nearby or not, but I see where your going with it.