This stuff reminds me of the buildup I used to get on my car battery terminals, It certainly looks quite yucky.
Do you have a gravity tank supply and if you have is there anything floating in it?
Perhaps this substance has been dislodged from the inside of the pipes when the plumbing was done.
I'm really surprised you've not had more answers.
Access to the tank is near impossible, perhaps a mirror on a stick with a torch taped to it - haven't had time to do that yet.
Unfortunately I cant test this muck either as I wiped it off after taking the pic. It came away very easily in one go using just kitchen paper. It didn't feel particularly gritty as you'd expect for a mineral deposit but looked more like a slime. I do live in a hard water area but also right next door to a water treatment plant which just adds to my concern.
So what is it?
If you look closely at the picture the smaller whiter flecks on the left side of the diffuser I recognize as limescale, (hard, brittle, slow forming) but the bulk of this gelatinous goo is clearly not. The tap is clean now but a few weeks from now this sludge will be back.
Hi
I had this problem 3 years ago and fitted a ScaleWizard to my water inlet pipe and after about 3 months the problem has all but disappeared. It works by putting an electrical wire closely looped12 times around your mains inlet and connected to the ScaleWizard`s terminals and left on 24/7 it uses only pennies per year to run and saves a fortune on appliances for more info go to
Thanks EDDIE51, that explanation makes sense and alleviates my concern. I've always associated limescale with the hard brittle type you tend to see on a kettle element. I'll verify it is limescale with the method you've suggested and no doubt follow kaw69's recommendation - thanks for the link.