I live in a hard water area so limescale etc is a constant problem. My shower is an absolute nightmare. The grout turns black and looks awful, scrubbing helps but It just looks a mess, there are also areas that I can't scrub. What I'm looking for is some sort of cleaner, probably gel, that I can apply and leave and then rinse/wipe off. All the shower cleaning stuff at the moment just runs off so it's useless. Any ideas/suggestions? thanks
Never in my experience has hard water turned grout black...like mentioned in your OP. No need to be rude....so I'll give answering the question a miss.
The grouting on my bathroom tiles, is doing the same, it's mould, and i have used jif, or cif to remove it, but it does come back. There are endless products on the market, but sticking a wall covering over it isn't going to solve the problem.
Sounds like mould to me. Rough surfaces such as lime-scale will give it a nice place to key on to. Use high strength proprietary mould killer and then try to get rid of lime-scale.
Elbow grease and a non metal scourer should remove the limescale from the surface of the tiles. Once that's done any black mould remaining on the grouting should be dug out and regrouted and the same with the silicon sealant as IMO none of the products available are that great...
The black will be mould and you will need to bleach it. Pour some thick bleach over it and scrub in with a nail brush, leave it for a couple of hours or overnight if it's really bad. give it another scrub then rinse off. Any really hard to get to places or if you find it slips off too quickly the soak a paper towel in bleach and press it against the offending area. If you do it regularly then it doesn't get so bad and is easier to get rid of. I am in a hard water area too and I always use shower shine spray after every shower as it stops the water droplets drying on the tiles and screen and marking them but they need to be clean to start with or it's a bit of a waste of time. To get rid of existing limescale marks you need something like Viacal or Limelite gel to scrub the tiles with first, leave for a while then rinse off and dry.