I have Joint custody of both of my children but still pay the full anount of child support. How do I get a more equitable arrangement?

It is important to note that a modification of the support payments require both a substantial and unanticipated change in circumstance.  It is assumed that when you enter into the stipulation you were fully aware of the costs associated with the amount of support you agreed upon. Moreover, even  the costs you were to bear with shared physical custody. You might look to file a downward modification but this depends are various factors. One would have to look at your stipulation and your current state of affairs to contemplate  your chances of prevailing in a downward modification.