We just bought a 1990 Hinter 30 from its original owner. The head system appears to be origianl factory hardware with the composite holding tank in the aft locker. Is there an economical way to purge the holding tank of the formaldehyde based tank treatment the PO used and allow the use of a more environmental friendly enzyme base treatment? If not, is there a reasonable compromise product available? Thanks!(Hey Clark. When you get all the leg work done on your bimini please come and talk to me!)