The UV light is worth the money. Look at the down side of being sick to death. It's well worth the up front expense. We filter all water going into the boat then filter it again at the sink. Regular water for showers and washing dishes etc. doesn't get filtered out of the tank but water we cook with, make ice with and drink comes out of a separate tap that has a regular charcoal filter. Once we cleaned the tanks out we didn't need to filter everything. It's worked so far. Having clean water on board isn't something you want to skimp on. IMHO