How can i remove brown stain fiberglass shower pan hard water/calicum

here is info that may help

https://www.youtube.com/watch?v=_8qeGsaAvi8

https://homeguides.sfgate.com/clean-lime-scale-fiberglass-showers-92664.html

Hydrogen peroxide has worked for me. Soak a cotton cloth in the hydrogen peroxide and apply it to the brown area and let it remain there for as long as possible, then scrub the area well with a brush, then rinse. This may need to be repeated, depending on the depth of the stain.

If you find that you are spending an hour trying to scrub your shower with no success, consider using Easy-Off oven cleaner to do the scrubbing for you. Just make sure that you are using the fume-free version in your bathroom. I used this stuff in hubby's bathroom and it was amazing how clean it looked when I was done.

https://www.hunker.com/13420724/how-to-clean-showers-with-easy-off-oven-cleaner

Use Easy Off No Fume Oven Cleaner. Spray it on, let it liquefy, and rinse well. Works on fiberglass, enamel, and porcelain

If your water has a lot of iron, it maybe its iron. I would get Iron Out to remove it. If its not iron, there is a hack for bathrooms using Easy Off Fume-Free Oven Cleaner and a white eraser. Be sure to open a window or turn on your overhead exhaust, I would wear a mask. https://www.youtube.com/watch?v=F5-OwoC6R0U

Try using Calcium deposit remover - available from the cleaning Isle for bathrooms.

Try CLR. It works great

Check into wet and forget shower. Also you can heat vinegar and add blue dawn 50/60.

Hi Susie, mix equal amounts of water and hydrogen peroxide and then combine the mixture with an equal part of cream of tartar. Apply to the stained area and leave to dry. Use a scrubbing brush (nonabrasive) to scrub the area. Rinse thoroughly with warm water.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.youtube.com/watch%3Fv%3D_8qeGsaAvi8&ved=2ahUKEwiSiqqsoJD1AhUTZt4KHcfQCtYQwqsBegQIFRAB&usg=AOvVaw2xCdqdn5vWcppaX9XRz-bO here is a guid which can help you.

Try CLR, available at diy stores.

Home Depot sells CLR it’s a cleaner soak a cloth in it and lay on the stain soak over night if it’s still there do again over night

CLR or even the Dollar store CLR brand. You can also use oven and grill cleaner, which the dollar store also sells

Try some oven and grill cleaner, make sure you have good ventilation