Just had a bathroom remodel and every time I turned on the tub, the water would come out brown first then clear up. This issue was isolated to the new tub only. Thank God for the internet tips that we found! The contractor took off the faucet head and we saw that the "nipple" (pipe that is coming out of the wall to connect to the faucet) was the culprit. It was all funky and brown and the bathroom is only 1 week old. He replaced that piece with brass and no more issues. Hope this helps anyone else who experiences a similar issue.