How do I get rid of limescale in my toilet?

Parazone is the only one that works for me.

Viacal spray. Spray onto the offending bits when the surface is dry and leave for as long as possible. Then it should scrap off easily - but don't use a metal scraper as that will mark the porcelain. I've used it on shower heads and around taps with no apparent damage to plastic or chrome. But only when it really needs doing.

We used Domestos Zero (in a black bottle) on a toilet in daughter’s rented house once. We think the build up had been there a long time. It worked really well. It’s much thicker than thick bleach and sticks to the limescale.

Use a strong limescale remover (there are some powerful ones on Ebay) and thereafter a Parazone or similar rim block and you will never have the problem again.
I did this on a thick build up in a house that DD rented.

Bleach tablets are good for keeping on top of it once you have cleared it. Killrock products are good too - we found them at B&Q.

We’ve used caustic soda* for a bad case. You do need rubber gloves and have to be very careful, not use the loo for a few hours, so not practical if you only have one, but it does work.
*Wilko stocks it.

I use Viakal on tiles/taps etc but don't think it would be strong enough for your task.
If you google the problem a few suggest citric acid, being careful re fumes. Clear most of water out, add acid and some hand hot water to cover stain. Leave for couple hours to let it work. Flush.
Or you might be able to get special stuff from plumbers merchant?

Do try Domestos in the black bottle. Get all the water out so your toilet is dry and leave it on for a good while.

Can I just caution using descaler round chrome taps and wastes. I have ruined a couple that way, it takes the chrome plating off if you leave it more than a couple of minutes. For limescale in the loo, as others have said, try to get the water out, then use a strong descaler, not just a loo cleaner, and leave it over night if you can. You may have to chip away with the handle of a spoon if it is really encrusted, it may leave scratch marks, but these will disappear in time with bleach.

or even a milton tab or similar and left overnight.

Have you tried Harpic Power Plus? I used it overnight for 2 nights as limescale stain was really bad and it cleared it.

Just out of interest, do you get all the water out?

I mean HOW do you get all the water out?

@25Avalon We used to find Harpic Power Plus worked very well, but it seems to be thinner these days, and doesn't cling as well. So I've bought some Toilet Duck to see if that's any better.

@sarahcyn I was wondering that too!

Coca-Cola has always worked for us, buy the original one two large bottles down the pan with force (this sends the water round the U bend) and leave overnight or twenty four/thirty six hours.

White vinegar and bicarbonate of soda, overnight. In Mlata we have "Acido Liquido" which does the job.

Spirits of Salts (Hydrochloric Acid) Best ever toilet cleaner. We live in a really hard water area. I just pour it into the toilet and leave for 30-60 minutes, then flush. Repeat if necessary. If it comes in a squirty bottle you can get up under the rim as well. It's very caustic and has a pungent smell so wear heavy duty gloves and a face mask. You used to be able to buy it in hardware stores but 'elf and safety have scuppered that, but Builders Merchants sell it. Builders also use it to clean brickwork, cement, drains and pipework. Keep it well out of the reach of children, preferably locked up - the spirits not the children!

I agree with Tanjamaltija. I use vinegar all the time for descaling taps, kettle, toilet, in my laundry rinse... , cleaning windows, etc.

My DD has this problem , I am sure it’s because they don’t flush the loo at night for fear of waking the kids. Every year when they go on holiday I go round with my rubber gloves and a pumice stone and rub the offending area, normally the bottom of the pan, it doesn’t scratch the porcelain bowl and works a treat.

I used Viakal original liquid (not the spray) on my daughter's toilet when she moved into rented accommodation. It clings better than the spray. Then I used an old debit card as a scraper so that I didn't scratch the surface. It worked a treat!

Agree with the Spirits of Salts. Empty the pan using an old baked bean can! Do make sure all the windows are open, use heavy duty rubber gloves and rinse thouroughly. That stuff would shift anything off anywhere.

@Sarahcyn, I get the water out by scooping using a disposable cup, which I empty into a bucket or jug, then I throw the water down the outside drain (or another loo)

When i moved into my house almost 4 years ago (old and unloved) the toilet had probably half an inch of limescale in it, previous owner a health visitor ?. Nothing worked so I literally had to get a knife to it and break it up..... gross!
Since had a new bathroom and use toilet duck daily, along with parazone on ‘good scrub’ days ?
Hope you get it sorted ?