Any advice for getting yellowish stains out of white clothes after several washes?

I have noticed that when I wash brand new white underwear, socks, bras, etc., over time, the garments develop a light yellowish color due to the water in my community. Someone in my house has contacted the water company several times to address the issue. The water company is insistent that there is nothing wrong with the water except for a slightly high level of sulphur. My family cannot buy white clothes because of this problem.Any advice for getting yellowish stains out of white clothes after several washes?
I have had a similar problem here in Costa Rica. I just take the items and soak them in a bleach/water solution. I leave them for about 1 hour and then rinse in the regular cycle and dry as normal. It works every time. I use about 1/2 cup bleach to 4 gallons of water.





Another solution via Martha Stewart: To whiten cloth napkins, linens, and even socks, fill a large pot with water, and drop in several slices of lemon. Bring to a boil, then turn off the heat. Add the linens, and let them soak for about an hour. Then launder as usual.Any advice for getting yellowish stains out of white clothes after several washes?
I have that problem, with hard water, out here in the desert, I soak my whites with OXI CLEAN, along with my detergent. then rince, then wash , using HOT water, Hope this helps, a little extra work, but worth it.....
Using cold water helps, and adding a cup of white vinegar to the wash also helps to keep clothes white.
use Zonrox bleach......we use deep well water here in philippines and our white clothes get yellowish after washing many times.....we just used bleach
THERE IS SOMETHING CALLED IRON OUT IT WORKS GREAT JUST ADD IT TO THE WASH, ALSO HOT WATER I NOTICED STAINS WORSE, SO TRY USING COLD WATER INSTEAD