What are these brown spots in the gunite of my pool? Chad in Richmond has noticed brown spots on the bottom of his pool in the gunite. What causes them and how do you get rid of them. We went to our HomeShow Pro for Pools, Colt, at US Pool for help. https://media.blubrry.com/homeshow/homeshowradio.com/wp-content/uploads/2019/11/EE-USP-191122-Brown-Spots.mp3Podcast: Play in new window