Ex back on drugs

So I'm pretty sure my ex is back on meth. We have a 7 month old and he has a 4 year old. We haven't been together since about a week before I was pregnant but I've been letting him visit the baby. I'm planning on calling cps to have them drug test him. Will he go to jail? How much jail.time? Will he get his 4 year old taken away?

Edit: I'm asking the process that will happen if I do call so I can make a decision about what needs to be done. As I'm sure most of you know meth addicts can become very violent and he does have a violent history. I don't want to see him go to jail so that's why I'm asking