Red stains obviously sounds like iron deposits. What was their reading for iron levels in the water they tested?

Realize that water standards are only about water safety (i.e. will someone get sick if they drink it). They have nothing to do with what is typically deemed satisfactory regarding taste, odor, hardness, etc. Specifically ask them what they are referring to regarding 'allowable levels'. Levels for safety of iron are much much higher that what is tolerable for aesthetics and taste. Anything above 0.5 ppm of iron is a whole lot of iron and will lead to staining, but you can drink water with many ppm's of iron in it and be 'safe'.

Since you have PEX plumbing and likely no iron pipes, the iron source is likely from the water source itself or from accumulation upstream of where your service joins. Do your neighbors experience this problem too? That will give you a clue as to the source.

Hi Buzzsaw -

Iron was my first thought too.

The water quality specialist was a little hard to understand so I'm going to have to ask him to fax me the results. Bear with me with these results. He did say that hardwater was 98 (not sure if 98% or .98 or what), the chlorine was 3.1, the PH was 7.4 and something about water clarity was.12. He said that because of the water clarity result that means that the iron level would be low??? The didn't make much sense to me, but then again I'm not a water quality specialist. He thinks that because the water tests are fine that it's something airborne in my new construction that reacts with the surfaces and turns them red. I've never heard of anything like that, but again, I'm not a water quality expert. I think I might need to have an independent analysis done.

So, is the color blood-red, or more orange? If orange, is it dark orange or light orange? Dark is likely iron, light could be chromium. Blood-red would be something else...

Tell him to give you the units of the contents as well. Does little w/o the units.
98 ppm of hardness is different than 98 grains; neither is too good...

The color is definitely red, not orange. If it let it go more than a few days in between cleanings (which is a pain) it starts turning really dark red.

He faxed me the results, but the quality was too poor to read. I didn't think that 98 hardness in any measurement was good. I'm surprised that public water would be that bad in terms of hardness?

It the red a 'slime' or a mineral deposit? There are some bacteria that leave a red stain.

I don't have an answer, but if you ever get one, please let me know! We have the same problem (northern VA here), building's only 2 years old (and has done it from the beginning), and no answers. I'm guessing some kind of bacteria or mold (not that it takes long to build up) but I really don't know. (my apologies if this posts twice, having form issues. >.

Did anyone ever figure this out? Could it actually be coming from the Pex Tubing (colored red)? We have a similar problem in our new house. I thought for sure it was iron, but the test just came back negative.