Sharing 50/50 custody

My ex and I were together for ten years but we split up a three years ago. He just spent the last year in jail and because of some decisions he's made since he came home I went and filled for full custody. I don't want to keep the kids from him so I've agreed to split custody 50/50. The only problem is my children always want to be at their dad's house. Idk how to address this so I'd appreciate and advice from people that have been in the same boat as I. Thank you in advance