Greetings! I thought that I would share a discovery that I made when I installed a Vulcan Draw Straw in my truck’s fuel tank last weekend. It was quite a surprise to me. I realize now why my truck is on its’ 5th LP. When I pulled the fuel tank module, the bottom screen was 75% covered with black and tan colored algae/fungi. The stuff was even on part of the top screen. When I cleaned out the fuel tank, I found numerous little blobs of the tan stuff. Other than that, the tank was spotless. As far as cleaning goes, all I did was wipe out the tank with lint free cloths as best I could. I had already drained virtually all of the fuel.

After I got everything back together, I decided to do some research on “diesel biocides”. I looked at three products: Racor Diesel Biocide; Power Services Biokleen Diesel Fuel Biocide and FPPFs’ Killem. I chose the Racor product based on its’ product description, price and the fact that it could be had in a 16 oz. container (treats 1,280 gals.). After I received it, I put 1 oz. in a full tank of fuel. The literature called for a “shock” treatment of 1 oz. for 40 gals. of fuel and .5 oz. for maintenance. I plan to put the biocide in one more tank of fuel after this application – just to be safe. After this is over, then I will put it in once a year.

The sad part about this is that I’ve known about using a biocide since I bought my truck in March 2002. I had read about this maintenance tip on several of the Dodge diesel websites; unfortunately I didn’t pay any attention to it. I changed the fuel filter on my truck once a year or 10k miles and never saw any evidence of algae/fungi contamination. In retrospect, I believe that my truck’s problem started with the fact that it sat on the dealers’ lot for 5 months before I bought it. Obviously the fuel tank had little fuel in it during that time. It probably had plenty of moisture in it though – great opportunity for the algae/fungi to get started.

 

Thanks for the write up. Can one simply add the biocide w/out dropping the tank and wiping any residual out w/ a rag? I have not had any problems with my fuel system yet, but seems like cheap insurance.

 

Yes, you can pour biocide into the tank through the fuel filler neck. I do it right before fueling so that it gets washed down the fill pipe by the fuel and stirred around. I put it in probably twice a year just as cheap insurance. It is a real mess when you get algae in the tank.

 

Of course you can - just put it in before you add the fuel. In my case, I put in some diesel additive/lubricant that I regularly use; then I put in the biocide followed by the diesel fuel. Obviously this stuff is extremely concentrated since 1 oz. treats 80 gals. As far as cleaning the inside of the fuel tank, I'm sure there are much better ways to do the job than what I did. I wanted to remove all of the algae/fungi that I saw. I'm sure that I left lots of bacteria that I couldn't see - that's why I'm using the biocide.

 

billmac, how close to the coast are you?
From what I can gather most of us living away from the coast especially in areas that get cold in the winter have no problem with algae or need for biocide.
I've been around diesels in the frigid north for close to 50 years and have never once encountered diesel algae.

 

If you have a doubt about algae (and thus water) in the fuel you may want to to polish filter the fuel thats in the tank with a pump and good diesel filter.
Biocide will kill any bugs but the gunk and water will keep clogging filters until its all gone.
Also Im liking my draw straw less and less.. any solution without slosh protection will inhale air at 1/4 tank and under.
The stock pickup has a float valve in it that traps passing fuel, but the pickups are small. I might buy an extra pickup assembly and try to modify it for larger flow volume.

 

That is amazing!!!
Here in the midwest it is a bit more common than that!!!
Most every farmer has seen it.
Must be directly related to temps.

 

I live in Fort Worth which is north central Texas. I guess that I'm about 300 miles to the Galveston coast. I think the problem is the humidity that we have here - it's usually high. I have always bought my diesel fuel from Valero/Diamond Shamrock which does have a refinery on the coast of Texas. Most of the time I use the same 2 stations where I fill up. The WIF indicator in my truck has never come on and as I indicated in my original post, I change the fuel filter once a year or 10k miles. I've never seen any algae/fungi in the fuel cannister or on the fuel filter.

As far as the Draw Straw is concerned, so far so good. Mine is sitting about 1/8th of an inch from the tank bottom. I installed a Fleetguard in-line filter just before the LP since I removed both screens from the module. Of course, I usually never let my truck get below 1/2 a tank. I did in this case because I wanted the tank virtually empty when I installed the Draw Straw. I had a 5 gallon can full of diesel that I poured in the tank when I finished the job.

 

Watch where you buy fuel. Water contamination greatly enhances algae growth.

 

One time my 85 Mercedes 300SD quit. The recommendation was to use Startron Diesel Additive. I bought it from West Marine. I added it to the tank & let it sit over night. It started & ran fine the next day - without a filter change. Of course, I changed the filter afterwards but the Startron fixed the problem.

 

Dropped my tank recently and found it clean as new. I have run B100 for the last 35,000 miles and add a biocide to it when I know the fuel will not have a quick use.

 

We fuel from our 500 gallon fuel storage tank, B100 for most of the year and B80 in the four colder months. Before each refueling I add the volume of biocide used for the 500 gallons to the few gallons remaining in the tank at least one day brfore the refueling - in a way a shock treatment. We've never had an algae issue in the 12 years we've had the storage tank, even with biodiesel which likes water.