Black gunk coming out of taps

[Elieza]

I’ve noticed a little black sludge coming out of my taps. There are also black streaks in the toilet bowl where the clean water comes out when flushed. If I don’t clean the taps and toilet for a few days it gradually appears. Mostly in the toilet.

I’m wondering if there is something in my (in loft, and lidded) water tank that could be causing this?

My dishwasher isn’t cleaning things properly either. It’s new. Taps in kitchen and bathroom are affected. Not sure if hot or cold water (or both) is causing it as monoblock style taps.

So could it be a build up of sludge in the water pipes (house is nearly 30 years old)?

Could the stopcock get bunged up with sludge also if the water is running through it so I may need it replaced too?

Is there an inline water filter that can be fitted to improve water quality that doesn’t need regular maintenance?

Thanks.

How lidded it the tank? Rats, squirrels, bats only need a tiny hole to squeeze through.

Run your cold kitchen tap into a glass . If it's happening at that tap then it's coming in from the main in the street- a water company problem. If it's only happening at other taps (hot or cold) then it's happening within the house and your problem to get sorted.

It’s not gunky in the water itself and the water company have said they are satisfied with the water quality in my street. So it’s up to me to sort.

The lid on the tank is secure. The water looked clean. The only thing I noticed was a noisy valve.

I know I need something done by a plumber and don’t want ripped off because I don’t know what I need!

One said on the phone I’d need a new stopcock and long lasting filter. I don’t know if that makes sense?