Preferred Residental Water Ph?

[Tom Bishop]

Hey, got kind of a wierd question. This all started when my next door neighbor starting developing pinhole leaks in his water pipes, lots of them, over the last year or so. His problems were mostly in his hot water system (which his plumber is telling him is aggravated by the hot water recirculation system in his house), but also in several cold water pipes as well. Well, they're now living the nightmare scenario of having to replace quite a few pipes in his house, and installing something that will "coat the inside of the pipes" (phosphate?). Anyway, we kind of freaked, because we have the same water source (one water provider providing water to our entire subdivision). So had a guy out to test the water.

What he said was that we had small amounts of copper in the hot water, much less copper but still non-zero in the cold water, and we had a Ph of exactly 7 both on the cold as well as the hot water side. Both results were a concern to the tester. We also had a hardness level of 10-11, which by itself wasn't a problem. He recommended a AN that would raise the Ph into the 7.4-7.5 range (to reduce our chances that normal variation in Ph wouldn't allow our water to become acidic), then a water softener to reduce the hardness back to a 4-5 range.

So my question is a simple one. Since 7 is neutral, one might think "Perfect. Don't do anything." But I'm also inclined to think I would like it higher than that just to avoid a possibility that it could dip below 7 and start us down the path of slow corrosion of our copper pipes. I'm also concerned that my cold water is exactly the same cold water that my neighbor has (although his house is about 8 years older than mine), so wondering if an ounce of prevention is worth a pound of cure. Can anyone help here?

[pawaterguy]

The phosphates are really all you need to try for now to treat the pipes. If the PH is 7 then it's ok and the problem isn't there. You could have a bad Langlier index which is a complicated thing to explain but amounts to too much dissolved oxygen in teh water which acts aggressively like a low PH would. Phosphates will generally do ok to treat it. Also, question anyone who talks about a softener that doesn't bring the hardness down to zero....because that's what the thing is there to do. Unless you for some reason don't want to have soft water after you pay to have a softener installed??? But, I wouldn't think the neutralizer is going to do anything for you here based on what you posted so but I would recommend a softener as anything over 4 is hard enough to benefit from a softener. But, I would at least try a phosphate cartridge installed in a standard 10" filter housing and go from there.

[Tom Bishop]

Okay, thanks. It sure is confusing, because everyone has a different story, so hard to know which one is correct. I just walked over to my neighbors (with several dozen 2" rubber hoses running throughout the house -- I'm guessing it's a phosphate treatment system of some sort)
and spoke to the plumber, who told me the same story I got from the neighbor who owns the house (too large a pump on the hot water recirc system); everyone else I speak to tells me this can't be true, so there you have it.

But just suppose I decide that the best thing is to get as close to "perfect water" as I can get. Is this a pH of 7 and a hardness of 0, or would I just buy a whole house RO filter system and be done with it?

[pawaterguy]

PH of 7 is what you want. 0 hardness is soft. A whole house RO would be overkill as you generally don't need low TDS water to shower/wash clothes and dishes in unless you have some medical reason to do so. As for the phosphate treatment...there are a couple of options. One is the way I described and it's the way my company always starts out. If it doesn't work you can always go to a phosphate injection system which would mean more money and upkeep but would give you the ability to fine tune the amount of phosphate solution you are injecting. Good luck!

[Andy CWS]

Before a solution is attempted consider all possible causes. There may be another issue at hand.

Common causes are:
• Low pH (acid water) typically found on private well water, but is also present in some small municipal water systems.

• Other water chemistry causes, such as high levels of dissolved oxygen, high levels of salts dissolved in the water, and/ or corrosion-causing bacteria such as sulfate or iron bacteria.

• Electrochemical causes, such as improper grounding of electrical appliances to the copper piping. Electric wires having contact with plumbing.

• High velocity of water, relative to size of piping, causing hydraulic wear on the piping, for instance a recirculating hot water system with a pump driving the water through pipes that are too small in diameter.

• Poor plumbing installation practices, including not cleaning or de-burring the pipe properly and the use of excessive flux in soldereing the pipe fittings.

• Sand, sediment or other grit causing hydraulic wear on the piping.

• Lightening strikes to utility poles where the electricity travels to ground wires connecting to piping systems.

• Galvanic corrosion; electrolytic corrosion

[Alex]

Tom Bishop, were you able to install the phosphate cartridge? (Like the PCC-106)

If so, How did that work out for your situation?

Thanks!