Fla. Stat. § 298.49

All bonds and coupons not paid at maturity shall bear interest at the rate of 6 percent per annum from maturity until paid, or until sufficient funds have been deposited at the place of payment, and the said interest shall be appropriated by the board of supervisors out of the penalties and interest collected on delinquent taxes or any other available funds of the district. Any expense incurred in paying said bonds and interest thereon, and a reasonable compensation to the bank or trust company for paying same, shall be paid out of other funds in the hands of the treasurer and collected for the purpose of meeting the expenses of administration.