Fuel problems come mostly from moisture. The vent to the outside allows the expansion and contraction of the tank contents by use and by temperature changes to exchange the air above the level of the tank. It also can allow moisture to condense in the tank The water
allows growth to form in the tank.
separator in the fuel system is designed to take care of that. You don't want water getting into the fuel system. It also can allow Algae to grow in the tank. That isn't so bad but they eventually die and settle in the tank. These accumulated dead bodies also are a problem and you fuel filter
will handle that too.
You fuel filter
system does a pretty good job of deal with all this in normal conditions and you don't have to worry most of the time. What can happen is conditions can make it possible to accumulate a lot of water. It happens when the fuel level is low and the boat is on the hard
during the winter. It's very common when you buy a boat that has been for sale on the hard
to have a fuel tank
full of crap.
A full tank minimizes the amount of air in the tank and reduces the amount of moisture you might condense. This is a good thing to do when you lay up the boat for a period. Tank treatments work to a point. If you have a lot of crap in the tank adding an algae treatment only kills the ones that are alive. It's the dead ones that make the problem. Many fuel facilities have the fuel treated already. I know it is where I get my fuel. Over treatment of tanks
is a bad thing to do. If you decide to follow a treatment program do it no more than directed and you probably need to do it with each fill. Once you have the problem it's too late.
You can find a lot of snake oil
and magic devices out there. Some claim to work better than others. Many claims are overstated. I've never seen any serious proof any of them actually help.
Changing your fuel filters often will alert you to rising problems. Take the filter apart after you change it and look inside. See what you see. If you see some stuff well you know the filter works.
If you have inspection ports
, open them up and look. If you have no inspection ports
consider adding them. They make port kits you can install without removing the tank.
Before you think about installing a fuel polishing system I would step back and do the math. A good dual Racor
500 system will provide good filtration and the ability to swap filters on the fly. Adding complexity has it's potential problems too. You might clog a filter some day. If you were out there swapping it would be very simple.