Is there anything that I (custodial parent) can do to reduce the amount of child support that I receive?

You can always give it back to him after you receive it. HOWEVER, I would be very careful in creating this pattern. If you do this he may take you back to court and have the Order reduced at a time when your child may need the extra support. Do you already have the child's college paid for? Depending on the school and the age of your child now, a college education may run upwards of $250,000. Think it over.