Blue stain in tub. Not acid water. Electrolysis?

Recently we had a small drip in one tub that left an aqua blue stain on the porcelain. I thought that it might be acidic water degrading the copper. When I tested the water 4 separate times the ph was 6.5-7.0. ( we have 2 wells that we can switch between and I tested at the well and inside the house) . While I was at the Home show at the fairgrounds this past weekend I talked to one of the water treatment vendors and told him about it and that we have hard water, 150 ppm. He suspected that the house ground was connected to the copper piping but that the pipe that goes to the well was plastic. It is. He suspected that some electrolysis was going on. I also told him that in the past 3 years, we have had several pinholes in the small copper pipes in the cellar. When they were replaced the copper was very thin. If it is true that the ground goes to the copper pipes in the house, coould that cause the pinholes and blue stains? How should it be grounded? I will crawl into the space this friday to check.

Btw He quoted me $3200 for an iron and sulfur filter/ softener setup. And he could check for all that is necessary. Iron is only 0.3.

Water below 7.2 is acidic. I don't know if water with your PH would eat copper as fast as you have described though. I don't think electrolysis could be the culprit either but stranger things have happened.

I would ask the electric company if they have any experience with this problem.

A few years ago, I found out that my well had a broken coupling at 40 feet. It took years, but the surface water with a PH of 5.5 found it's way down to that coupling and was turning my shower blue. I now have a new well and that one is plugged with bentonite. That's about the extent of my experience with low PH and copper.

bob...

I will check for connections by the phone company. No cable in our area. Would the grounding of the electrical panel to the copper pipes without any metal pipe going to the earth leave the house without proper ground and lead to electrolysis?

There are many potential causes for pinholes in copper tubing. They are; low pH acidic water (the pH scale is 0-14, less than 7.0 pH is acidic, 7.0 is neutral, above 7.0 is alkaline), high content DO, CO2 and TDS, high velocity, hot water recirculation systems, bacteria, using the main water line as the building's ground electrode, grounding appliances and other electrical equipment to the water lines and electrolysis from different type metals in the system or a bad ground on the water heater etc. etc.. I think that's all of them but I may be missing one or two. Like excessive soldering flux and not reaming the ends of the copper tubing.

Also, water companies are allowed by the EPA to not sample water from houses for their compliance for the Lead and Copper Rules, that are less than 5 years old, because the new copper will not have a protective coating of corrosion or hardness scale to prevent excessive copper and thereby the water company would not be in compliance with the Rules.

If you don't not have H2S (sulfur), you do not need an iron/sulfur filter for the small amount of iron in your water. I suggest a correctly sized softener for the number of people and bathrooms and the type of fixtures in them, with the Clack WS-1 control valve. You can all about sizing on my web site.

Cavitation erosion will also make holes in copper water pipes over time. How fast the holes appear depends on the amount and speed of water running through the pipes. EVERYTHING wears out over time, even copper pipes.

The wire is NOT hooked to the pipe to provide a ground.

The wire bonds the pipe to the electrical panel so that the entire plumbing system does not become a shock hazard when an energized wire accidentally makes contact with metal plumbing in the residence.

Cacher_chick,
Does that mean that there must also be a ground strap/wire from the panel to the earth? If there is not one, then what?

Boerdoc,
do you have forced hot air? If so, i would look for any spots where the heating ducts are touching the copper pipe. I had a customer with the same issue and we resolved it by putting non conductors in between the copper pipe and the ducts.

sammy

www.tylerwellandpump.com

Cacher_chick,
Does that mean that there must also be a ground strap/wire from the panel to the earth? If there is not one, then what?

Click to expand...

Per current NEC, there must be ground rods installed.

If you want more info about this, try posting in the electrical forum.

Well I got home and looked into the electrical panels Both have grounds that go into the ground somewhere under the driveway. But! I also looked at the copper pipe that had the pinholes and it is the pipe that has a large copper ground twisted cable probably 5/16" diameter connected to it. I never noticed it before. This makes me think that I want an alternative ground.

sammyhydro11,
There is no touching of the pipes. All the vents are insulated.

Cacher_chick,
I will post in electrical.

Yes pipes are bonded but, security, phone, satellite etc. guys also ground their systems to water lines. And if we look, electric water heaters basically ground water lines too, but sparky types will probably reject that idea.