A good way to get water stains out of upholstery is to mix 1/2 cup of vinegar with 2 cups of water in a spray bottle or squirt bottle.
Then spray or squirt the vinegar and water solution onto the upholstery.
After that use a white microfiber cloth to blot the water stain out of the upholstery and then continue to spray the water stains with the vinegar and continue to blot the water stain.
Then use a fan to help dry the water stain out.
You can also use an upholstery cleaner which is handheld that will help clean the upholstery and help remove the water stain.
You may be surprised at how much dirt and grime comes out of your couch or other upholstery when using an upholstery cleaning machine.