Using minor children as messengers for support or other contested issues is not appropriate. That being said, it sounds like you've had your ex held in contempt before. If you know he has the ability to pay more, an additional contempt hearing may lead to his incarceration and require that he pay a "purge amount" to get out.
This is only general advice and should not be considered a specific legal assessment of your case or advice that would create an attorney-client relationship. For a consultation contact our office at (352) 593-5990.