My name is Duane, I am writing this blog for Diesel Motorhome Owners... Just want to let you all know, that you do not have to be changing your diesel fuel filters every year... I change my fuel filters every 2 years, once I even went 3 years and have been doing this for over 20 years.. When I due change them, I can tell you, they are as clean as the day I installed them ! Here is the reason why ! - I have used "Howes Diesel Treatment" and a "Diesel Biocide additive in my fuel, every time I fill up... To make it easier to pour into the fill hole,... I purchase 12 long neck, plastic wine bottle on Amazon.com... I then add 1 oz. of diesel biocide to each of the bottles and then fill the rest of the bottle with the Howe's..... As I said, I have been doing this for over 20 years.. I can also tell you, I have never had a plugged a fuel filter or even any sign of algae in any of my fuel filters - In fact my filters are as clean as the day I put them on !..