Rust stain on bath tub

- Baking soda + a bit of water → make a paste, leave 15–20 mins, then scrub gently - White vinegar on a cloth/paper towel → place over the stain for 20–30 mins - Magic eraser can help for lighter stains For stubborn stains, try Bar Keepers Friend Soft Cleanser (the liquid one is safer than powder for plastic)

Don't think that is rust as the tub is plastic. Try brush by using a sponge or green wool, it should goes off. If it doesn't, apply some detergent.

I just replastered white paint for tub on top of it. If I can’t see it then it won’t annoy me :)

Try using vinegar?