Algae in fuel tank

So, what should I expect?  Will driving it and letting the filter take out the furballs work?  I assume the biocide will not "dissolve" them.  I expect to change the filters several times before leaving here in a month.  Is there something to dissolve them?  My first thought was to have the tank pumped out, but not sure that would get all the furballs out!!  How many of them would cling to the tank and surge plates inside?  I will keep the biocide in for now and replace it as I add fuel.

I know there are folks that have been through this before so I would be interested in your feedback on how you handled it and any do's and don'ts you care to share.

Thanks in advance for any feed back!

Changed the filters and added algaecide to the fuel and started it up again.  Same result.

To make a long saga shorter...
Wound up pumping the tank dry of 90 gals.

In the barrels, it was cloudy and didn't smell like any diesel I've been exposed to.

Tried to start a trash fire and the stuff wouldn't burn.

Drained the tank, then added 20 gallons with Biocide.

Replaced filters and started her up.

Ran just fine.

Waited another week and it ran fine with no residue in the filter sump.

Filled up , added Biocide (and every tank since then) and off we went.

It hurt to lose 90 gallons of fuel, and it burns me to this day.

But...
No damage to the engine due to the excellent filter system.  The junk COULD HAVE blown an injector or three.

I'll not run again without fuel additives.

Just relating our experience...
Good luck.

As to the drain or run with the contaminated fuel question it is mostly an issue of how bad the contamination is.  If it is pretty bad, say it is going to foul several of filters you'd want to drain it as the filters are going to get expensive
and be a hassle when traveling.  If it is not so bad and your filters are lasting longer you would probably be better off to just burn the fuel and keep it treated for a while.

If you filled the tank and sloshed the fuel/biocide around pretty good to kill of the stuff growing in there it shouldn't get worse and you might be able to skip adding more biocide when you are using fuel on a regular basis but I'd keep it up for a few months just to be safe.

I've had fuel in steel tanks for several years (farm fuel and heating oil) and not had a problem.  Usually algae requires light and stuff to grow.  Are you sure that you didn't just get a load of ???? fuel?

Friend of mine got some real bad fuel.  They were just filling the tanks and stirred it all up.  His home owners covered the repairs (I know?? but they did). He also had 2 witnesses in the truck with him, receipts, AND 4 - 5 gallons for a backhoe. WATER.  Bill was $5400 and his deductible was $500.

At the least if you must use the unit, keep an eye on your filters if they are the see through variety RACOR filters you'll have a better idea when to change them.  You will be changing them often.  By often, I mean daily for a while
or even more depending on the severity of the algae, until the black slime does not show in the filters.  sorry there is no easy fix.

ULSD will not retain water due to its molecular make-up.  So even the smallest amount of water will collect at the bottom of the tank.  I have seen a teaspoon of water support a colony of bacteria.

Once a bacteria colony takes up residence, eviction is pretty difficult.  A biocide and full scale chemical attack are about the only real chances for victory.  This is especially once an infestation has occurred and if the vehicle will sit for a prolonged period of time.

Good luck - PM me or call if you have additional questions.  I have spent a good portion of a 30 year engineering career dealing with these bugs - published a paper, etc.  In a way, the bacteria are kind of fascinating but they can also be very expensive.

Algae, Not the Other White Meat.

Safe Travels!

Can't say that would work for everyone, but it worked for us at the time.

Thanks for the inputs above.  I appreciated the advice.  The article on Algae-X from VeganFlyer seemed to follow on with RWinslow's advice.  I am hoping I caught this before it got too bad.  I am at Patrick AFB in East Central FL for several weeks, but have biocide in the tank at shock levels and will drive it weekly and add new fuel with biocide at shock levels.  Will change filters as needed and keep close eye the issue for several months. When we leave here we will be traveling until Jan when we get to Quartzite for the month and I will certainly use it when we stop for a month!  Will keep the biocide at treatment levels for several months or longer as needed.

If it appears I don't have it under control I will look at the drain or polish options.  When we leave here we will be working our way to RI so there will be opportunities to access the marine businesses along the way.

Thanks again for the inputs.

I scanned the article quoted above, with respect to ULSD (Ultra Low Sulfur Diesel) some of the representations in the article are not an issue any more. However, ULSD, if water can get into the system, will support biologic activity.  If you are parked in a warm / high humidity area and do not frequently drive your rig, then a biocide in the fuel is probably prudent preventative maintenance.

Hydroburn, Power Service 9-1-1, and of course the preferred method_fuel filtration and water separators.

The problem I see is if I leave the water in the tank it continues to promote the algae growth, if I "dissolve" it and it passed thru the water separator it will be detrimental to the fuel injection system.  That leaves the other recommended solution - drain the fuel tank.

For now I am going to monitor the fuel/water separator, drain the cup frequently, and keep the biocide at shock level for several weeks.  While we are FT, we are currently back in home territory for medical appointments and visit family and friends and driving the RV is limited to some short trips (20 mi or so) for some scheduled routine service and maintenance not associated with this issue.  However, I am anxious to get on the road and use up the fuel that is there from our 3 month stay in the Keys!!

Thanks again for the inputs!!

Your fuel tanks may have a small hex head cap screw / bolt on the bottom - mine are a 5/16" hex head.  These can be used to drain the water out of the bottom of the tank, but it is a bit messy.  I have also had luck inserting a small clear plastic tube down into the bottom of the tank, through the filler neck and sucking the water out that way.  However it is helpful to be able to see the water in the bottom of tank through the filler neck.

The most typical method of introducing the water into the fuel tanks is through humid air.  As the tanks are heated by the sun, the air and fuel in the tanks warms up.  When night falls and the temp cools off significantly (i.e. spring time), the fuel in the tank will cool and the warm daytime air in the tank will also cool.  Since the cool night air in the tank is more dense than the daytime air, additional air flows into the tanks through the tank vents (if the tanks were not vented they would collapse due to the partial vacuum).  This night air is loaded with moisture (that is why you have dew on your windshield in the AM) and after several nights of this activity, water will become present in the fuel.  Obviously, the smaller the amount of air that is drawn into the tanks each night, the less moisture introduction opportunity - hence the old advice to keep the fuel tanks full when not in operation.

I will look into draining from the bottom of the tank.  Removing 5 gal or so after it has been sitting for awhile would seem to be a good idea/ safeguard.

Thanks again for all the inputs. They do help

I moved the RV to FHU today so fuel is "disturbed" but will not move for another few weeks so will give it time to settle in a few days.  May try it then.

Anyone with water in fuel may be interested in this product.  If I use I will report back!