Board Thread:Naruto Discussions/@comment-34700383-20180829185752/@comment-6769189-20180906042811

Not everyone inherits KKG from their parents. Its entirely possiblebthat Shukkaku's presence brought out the gene, but at the same time Gaara had already developed in the womb he had it already. According to the wiki, his basic sand control comes from infusing the sand with his chakra(there isnt citation but i think i remember it being said), and he uses magnet release as a last resort to make it denser.