What caused a slimy wormlike mass to clog a dishwasher filter?

[gnome]

OK, probably not extraterrestrial, but it did pique your interest. :)

After my dishwasher recently stopped working I learned that it has a small filter/strainer located just before the water inlet valve so I disconnected the water supply and found this slimy wormlike mass completely clogging the strainer. To put it in perspective, the dish in the photo is a roughly 12" diameter plastic dish that goes under a flowerpot. The smallest mass on the right side was in the filter itself. The long piece in the middle was bunched up immediately behind it, and together they (not surprisingly) completely cut off the water supply to the dishwasher. The piece on the left was still in the pipe or the supply hose coming from under the sink, and appeared a few minutes later when I ran the water into a bucket just to be sure the line was flushed clean.

It looks "wormlike" although I'm pretty sure it's not actually a worm, but it was slimy and held together when lifted and moved about. As you can see the color varies from bluish to whitish to brownish.

The water comes from our own well, and there's no way that this passed through the whole-house (AquaPure 5 micron) water filter, so whatever it is it formed inside the house in the water supply. I was initially thinking it was a bacterial or algal mass, but could it be some sort of aluminum hydroxide gel formed from water heater anode electrolysis?

We drink the tap water all the time and nobody's experienced any hint of illness from it.

The water pipes are a combination of the original copper and some more recent pex sections. Our water has a fairly high iron content but otherwise unexceptional. The only other possibly relevant thing I can think of is that years ago the water occasionally had a sulfur dioxide odor after we had been away and hadn't used it for a week or more but that hasn't happened in recent years (probably not since the last water heater replacement).

 

[Tom.G]

That blue section in the large 'worm' looks an awful lot like Copper Sulfate. Probably a minor constituent of whatever the gel is. You could try taking the samples to your local county agricultural department or health department for a perhaps free analysis... you might even find someone that has seen it before!

IIRC, the sacrificial anode in the water heater is Zinc. The Sulfur compound from an unused water heater is not uncommon and (unsure here) due to bacterial growth in combination with the anode interaction. Both the blue color and your experience with the Sulfur smell indicate at least some Sulfur in the water supply. Even city water will support that Sulfur smell in hot water tanks. (takes forever to flush it out!)

p.s. Keep the samples moist in the meantime (easier to identify in their natural state). Maybe even try to get a small piece of one of them to grow.

Please keep us updated!

p.p.s As you suggested, they could be a bacterial or algal colony taken residence in the AquaPure filter and its housing. I lean more toward algal.

 

[gnome]

Unfortunately I discovered it shortly before going away for the weekend. I was reluctant to leave it lying around and disposed of it in the trash.

But later this week I will remove and check all the faucet aerators and see if I can flush any more of this stuff out of any of the pipes. I'll also check the AquaPure filter and housing, although I don't expect to find anything there -- I do change the filter regularly and have never seen anything resembling this.

If I find any more I'll definitely follow up on it. I was just hoping I might find someone here who has previously seen something like this.

PS: I believe the anodes in water heaters are commonly magnesium, aluminum or aluminum/zinc alloy. If this stuff is related to that, it must have been stuck somewhere in the pipes for several years, as we now have a tankless gas heater that presumably has no sacrificial anode.

 

[Rogue]

Might be daft, but could it not just be a seal/pipe-weld that has come away somewhere?
Is it strong/stretchy or does it fall apart readily?

 

[the professor]

5 micron filter?check out the astm standards for water purication-city and state codes-do you have a backflow preventer-- good luck

 

[Asymptotic]

Your "worms" do resemble bacterial colonies 'stretched out' by living inside pipes. Lift the top off of your toilet water reservoir, and look around. Are the sides stained with orange deposits that are slick to the touch? Does the water surface have an iridescent sheen? Either or both suggest the presence of iron bacteria.

To reinforce @the professor's question, 5 micron is coarse enough to allow most bacteria to pass through. Try a 0.5 micron filter element (0.5 micron is small enough to block most bacteria). If 0.5 micron reduces flow rate too much, try a 1 micron instead. Improved filtration won't do anything about an existing infestation downstream from the filter, but will reduce the potential for re-infection.

Biofilms are difficult to eradicate once they've been established. Shock chlorination doesn't penetrate too deeply past the surface, and a regime of repeated treatments is required. Copper-bearing molecules have antimicrobial properties. If you can get at them for inspection (or add unions in strategic locations) pay particular attention to PEX/PVC line segments; that's where any bacteria living in the plumbing is likely to be.

 

[Theodore2]

Thank goodness you found them! These look like "George" and "Mabel", who were accidentally released from our lab three weeks ago.

They've both grown considerably since we last saw them. Apparently there is something in your dishwasher supply line they find attractive.

Would you be so good as to keep them safe until one of our lab workers can come by and retreives them?

Dr. P. Chabane, Dir. BioPharm Labs LLC

 

[Tom.G]

Shock chlorination doesn't penetrate too deeply past the surface, and a regime of repeated treatments is required.

Just an FYI:
I've found that heavy Chlorine dosing damages the Flush Valve (Flapper Valve) in the toilet water reservoir. Suggest you have one or two spares on hand.

 

[gnome]

Still alive & well.

I've inspected the strainers at every faucet and showerhead and found nothing but a little of the usual grit here and there. Also checked all toilet tanks & found nothing concerning. So I have a new hypothesis which I will assume true unless something arises to prove otherwise.

Sorry, it's really pretty mundane but I didn't want to leave the thread hanging...

"George" and "Mabel" were delicate and flimsy but I realized that if gently expanded to their full diameters they would just about match the inside diameter (about 8mm) of the supply line. My ~5 year old dishwasher came with this http://www.bosch-home.com/us/store/accessories/00674387 which extends about 4 - 5 feet out the back, more than enough to reach under the sink & still have enough slack to slide the dishwasher out for service but it turns out that the installer left the old 5 foot braided supply hose that had supplied the old dishwasher for at least 20 years coiled up with twist-ties under the sink. About 2 months ago the dishwasher displayed an error code indicating water in the overflow pan and (not knowing that there was enough slack in the new line) I untied and extended that old hose as I slid the dw out to empty the pan. Then I just put everything back the way I had found it.

So, my theory is that I must have loosened a film that had formed in that old supply line which was continuously filled with water over 25 or more years and over the next few weeks George broke loose & clogged the filter of the new line (Mabel broke loose when I flushed the line after disconnecting it).

Needless to say I have discarded the old supply line and replaced it with a new 20" piece, quite enough to connect to the built-in aquastop hose, and unless it gets clogged again with similar stuff I'll consider the matter closed.