How to keep tub surround from turning yellow from hard water?

You might try cleaning the area REALLY well, then applying a car wax and buffing it well to keep the hard water from building up on the surround. There is also a product available at Home Depot that repels water. They were demonstrating it a year or so ago....ask in their paint department. The water they sprayed onto the wood and then sprayed water onto the area and the water virtually ran off of the wood. Sorry, that I can't remember the name of it. They said it could be applied to shoes, clothing, porches, etc. to repel water.

There are a few options to consider.

1) waterproof coating paint.

2) Install Ceramic or glass tile roughly 18" above the tub.

3)Tileboard.

4) Vinyl-coated wall paper.

Option 1 and 4 require the least amount of work. Be sure to seal with waterproof caulk. Here is a link to the best caulk to use: https://amzn.to/2N1Ph4E

Try using Lime Away or Rust be Gone. Spray it on, let sit, wipe off and rinse well. Many Hometalk members use their own home made products. Read some of their great remedies on this web site!

I have the same problem. I can tell you how to clean it but I don't know how to keep it from happening.

To remove hard-water stains from your tub, pour in 3 cups white vinegar under running hot tap water. Let the tub fill up over the stains and allow it to soak for four hours. When the water drains out, you should be able to easily scrub off the stains.