Stain?

Try a product called 'Scouring Stick'. It's pumice and is available at Walmart.

Try a descaler. I’ve had great luck with Fuller and I bought a toilet bowl kit off QVC a while back. It has swabs, cleaner, and scouring stick. It’s been the best to remove and prevent issues.

I use several squirts of Dawn dish liquid. Then pour about 1/3 gallon of vinegar. Agitate with a toilet brush to form suds. Let it sit for about an hour or two. Then scrub with a toilet brush. The suds suspend the vinegar above the water line.

How to Remove Hard Water Stains in a Toilet

https://www.thespruce.com/hard-water-stains-in-the-toilet-2719033

Here are a collection of techniques you can try:

https://www.tipsbulletin.com/how-to-get-rid-of-hard-water-stains-in-a-toilet/

Pumice stone

Use white vinegar and dawn mixed with ajax. Let it stay for about an hour then scrub with a green scrubbie.

Hello. After failing with many proprietary chemicals and retail shelves the problem is solved.

My solution was the pumice stick. This is excellent way to remove stains and rings in the toilet. When commercial toilet cleaners fail -this is my go to. Great for thick crusted calcium mineral build up that the toilet waterbowl collcts.

They are found at my local Walmart for less than two dollars -good for multiple uses. Be sure to follow the use instructions, soaking the pumice stone in water for a few minutes. While the stone is soaking, grab your toilet brush and splash water up around the ring. Note: It’s very important to keep both the stone and the surface wet while cleaning to avoid scratching your porcelain.

http://www.quickanddirtytips.com/house-home/housekeeping/how-remove-hard-water-stains

How to Remove Hard Water Stains in a Toilet

www.thespruce.com/hard-water-stains-in-the-toilet-2719033

Give this a try, Coke worked for us here

https://www.today.com/home/clean-your-toilet-coca-cola-plus-4-other-genius-spring-t119479

Pour Lemon juice in and let sit overnight. It dissolves all dirt and hard water. Wipe with brush and leaves room smelling for good too.

You need to clog the toilet so it won’t go down then add more water to we’re line is then add CLR and let sit over night

Try iron out: https://amzn.to/3tVmlm8

First, flush the toilet and then pour a quarter of a cup of Borax into it, using your toilet brush to swish it around. Next, add one to two cups of vinegar and let the mixture sit for 20-30 minutes. You should be able to scrub the stains away and flush the toilet to reveal a fresh, and clean bowl.

I use young livings thieves cleaner on my toilet