How often, on average, do you have to change your racor fuel filters? *Are you running a single or dual filter set up? *We've put about 25-30 hours on the boat since we bought her in August (and we had her out of the water for about 5 weeks since purchase to get the fiberglass deck repair done) and have not had to change our filters yet at all. *Reason I ask is that we have s single racor primary filter (as well as dual secondary/final filters at the engine) right now. *I am debating whether I ought to go to the expense of setting up a second racor as back up. *In other words, keep running off just one but have a manifold installed so that if it goes down I can just switch the manifold over to the 2nd racor and continue on my way instead of having to change it right then and there in potentially adverse conditions. *Anyone done this recently on their trawler? *What was the ballpark cost?*What say ye?