record, we conclude that there was no substantial, competent evidence to support the trial court’s finding that the former husband had the ability to pay the full amount of the previously ordered support and arrearages and willfully refused to pay the same. See Larsen v. Larsen, 854 So.2d 293 (Fla. 4th DCA 2003) (reversing trial court’s order finding former husband in contempt for failing to pay child support because the order was not supported by substantial competent evidence of his ability to pay). Further, we reverse that portion of the order requiring an additional $200 per month in child support until the arrearages are paid as an abuse of discretion since that would make his court-ordered obligations exceed his income. See Butchart v. Butchart, 469 So.2d 965 (Fla. 4th DCA 1985) (<HOLDING>). Accordingly, we reverse the order finding the
recognizing that questions of changed conditions and the amount of child support must be resolved on the particular facts of each case holding the amount imposed to reduce child support arrearages must be reasonable holding that child support arrearages may not be included in a chapter 13 plan holding that where payments are made on past due support they must first be applied to  current child support installments due then to accrued and outstanding interest on  delinquent child support obligations and finally to the principal amount due on unpaid child support recognizing that child support arrearages are imposable by law from the date of a childs birth