Bathtub Limescale, Soap Scum, Hair Dye removal

Upgrade your vinegar. Go to the Eastern European shop and get the 20% pickling vinegar. Wear gloves, AND OPEN A WINDOW. Try using with a Magic Eraser pad (white "sponge").
Or invest in some hydrogen peroxide. Not the cheap stuff. Go for 6%+. Again with the eraser.
Or Pink Stuff cleaning paste, and patience.
I clean anything with that lot, including rust, greasy engines, and decoking a diesel engine.
If that lot fails then you might need to consider painting the bath

YOu could try Viakal on the limescale/soap scum, I have just successfully removed the same from a basin with that - I used the stuff that comes in a bottle which is quite thick, rather than the thinner spray stuff, and soaked some kitchen roll in it and stuck it to the affected area for a while so that it stayed put rather than all draining off. Not sure whether that would be any good on the hair dye though.

What is the bathtub surface, plastic/enamelled metal? would need to check you won't damage the surface. IF it's enamelled and already worn off then you might need to look at re-enamelling

You need limescale remover (about £1 in tesco for 750ml. Same as viakal really but a fraction of the price).

Wipe over the tub with a sponge and leave for 30 minutes, scrub, then rinse


All bleach does is it make it white. Doesn't remove limescale whatsoever.

Bicarb of soda, vinegar and hot water is for clearing blocked pipes (edited)

Another option is to make a strong critic acid solution. The granules are cheap enough. Buy enough granules to be able to fill the bath to the level you need with water, and make a solution that you could leave for a few days if necessary. It will clean the pipes on the way out.
I have found the oxi powders you can get, added to a citric acid or hydrogen peroxide solution, can help boost a reaction. Making the solution with hand temperature water also helps

The pink stuff