Well, as I understand, since cannabis is legal on the Federal level in California, you shouldn't have any issues even if they find it in your blood. However, I would recommend you not to take the risk, as there are a lot of employers who are still skeptical about people who take weed or any products related to it. Since weed became legal in California, I have been looking for all the best methods of growing weed at home as I don't want to order my stuff every time I need it, as I don't smoke that often.