Black stuff

What's the best way to clean off and then prevent the black stuff that forms in the flexible pipe going to the bathroom shower head?

Are you sure that the black stuff isn't the rubber lining inside the pipe?

Good thought Alan but no, it's not that. There's no leak of water and this is black flaky stuff that can be cleaned off but it's a PITA as you have to go round the pipe, not top to bottom.

Hard to say. After 20 years I don't have any such

You could try a solution of benzalkonium chloride from a spray bottle

It is mould and bacteria. Bleach will kill it, a brush will get it off.

Not IME. Nothing shifts it.

We've got some that builds up on the bottom of SWMBO bathchair. Most of it can be mechanically removed by a bit of pressure and scrubbing. But some remains and washing powder, bleach or Milton won't shift it. Beyond that you're going to start to damage whatever the things made of.

Possibly mould ingrained in limescale.

IMO citric acid works better than acids like vinegar. Highly dyed toilet limescale removers may stain anything that isn't porcelain.

To keep some surfaces wet until the limescale is removed soak a tissue in the liquid and wrap it around the object to be de-scaled.

If the OP lives in a hard water area it's the most probably explanation. We are in a hard/very hard water area (299mg calcium carbonate per litre) and black mould in limescale is a difficult problem to deal with. It's necessary to use a limescale remover before using a mould remover.

Lidl used to do a gel-based limescale remover which worked well, but...

I've been using citric acid for years to remove limescale from kettles, and it's very effective. However, for vertical surfaces and awkward areas it doesn't hang around long enough, even when using a soaked tissue. When the Kilrock stuff runs out, I'm going to make some citric acid gel from a conc solution of citric acid mixed into a cheapo hair gel to make a "non-runny" gel.

All we really need now is something to remove the black mould staining the rubber door seal of the washing machine. Bleach doesn't touch it. :-(

The only thing that shifts black mould on my patio is Benzalkonium chloride

We have what must be the softest water in the UK. Our 15 year old kettle still looks like new.

AFAIK our water comes from Wales via the engineering genius of the Elan aqueduct.

That looks like a good idea, cheers Tim. Ordered.

It's fungus, quite possibly the Aspergillus family. It's definitely worth getting rid of it. Aspergillus fungi produce airborne spores that can cause serious lung infections (Aspergillosis.)

Unscrew the pipe from the shower body and head and stick it in the dishwasher if you have one, or inside a pillowcase and wash it in the washing machine.

GH

And that's the same preservative used in medical eye drops like COSOPT and Monopost etc. Makes your face look like one of those Chinese dogs with loads of folded skin in their face if you become sensitised to it (as has happened to me, so now I have to have the Preservative-free variant).