Thrips prevention

Hi guys first time grower here. I had a thrips problem in my tent and I bought some of those blue sticky traps plus some of captain jacks. The instructions on the bottle say to spray it all over and then leave it for five days. My question is, how will I know when the thrips are gone for good? I’m waiting to flip my plants to flower because I don’t want them causing any issues with future buds. I’d like to know that most if not all of them are gone before I flip. I’ve only ever seen maybe one since they’re so small, but usually can just tell based on the leaves. Does anyone have any advice? Thanks in advance! (: