I have noticed my fuel pressure dropping over the last several weeks. Today, I was sitting at a signal light and the fuel pressure slowly went from 9 PSI to 0 PSI and woulld not climb back up. I shut it off and ran the lift pump for the duration the pressure creeped up to 9 psi but as soon as I started the truck it quickly dropped to 0 psi. I assumed the lift pump was bad. I dropped the fuell tank and much to my surprise, the strainer is clogged with sticky brown gunk. I drained the tank, there is a heavy yellow to dark brown heavy film on the inside of the tank. I used some gasoline and it seems to clean it up. Does anyone know what this it. The gasoline makes it come off in clumps. However it is impractical to try to clean the whole tank with gas, my arms aren't that long. Does anyone have any ideas or suggestions, what this is. I was told it might be algea, I don't really know what the stuff looks like in diesel. I hope this is not algea, because I have 300 gallons in a storage tank. If it is algea how do I treat it.