Algae in Diesel Tank

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Cold Shot

Veteran Member
Joined
Feb 27, 2019
Messages
26
Location
U.S.A
Vessel Name
Cold Shot
Vessel Make
1997 38' Luhrs Tournament Open
Diesel Fuel Algae problem
A few months ago I added a product in the 350 gallon main diesel tank called killem. It’s killed all the algae in the tank but now I have large pieces of it clogging the Racor filter. I’m looking to rig up an in-line screen filter that’s petroleum resistant that can filter out all the large trash so the Racors can do their jobs for the smaller particles. I drew diagrams of the current and new systems. The fuel intake and return hoses are 1/2”.
The new system will have all the fuel running into this screen filter. When running it will eventually clog up the screen and will restrict the fuel flow. At that time I can close the valve for the screen and open the one to the Racor. Then clean the screen out and reverse the valves again to start running. I found a brass fitting for it but I’m now looking for a large screen filter. Anyone have experience with this issue? Will a seawater strainer work? We had to be towed in from offshore Sunday ?
 

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I would contact a local fuel polishing outfit. Most harbors with commercial fleets
will have a mobile boat that can come to your boat and clean (polish) your fuel.
It would be very helpful if your tanks had inspection ports or large fitting plates.
You need to agitate the fuel in the tanks enough to get all the debris out or even
the polishing will not be a permanent fix.
 
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You need to rig up a pump and circulate the fuel out of the tank, through a Racor with 30 micron element then through a Racor with finer element and back into the tank. Run it long enough and the tank should be clean, depending on where the fuel pick up is located.

The pump needs to be strong enough to agitate the fuel on the bottom of the tank. If you have access ports on your tanks, you can clean the tank through the access.

A water strainer will take the large particles out but not the medium and fine particles.

Google or search TF for fuel polishing or fuel cleaning. It's been discussed a lot.

Or hire a fuel polishing company.
 
Greetings,
Mr. CS. Algae does NOT grow in fuel tanks BUT there are microorganisms that do. The "bugs" need water so you must have water in your tank(s). The Killem did it's work and killed all the bugs and that stuff that's clogging your filters is dead "bug" bodies (bio mass). As suggested, you can have the fuel polished or make your own filter type system. In any case, you must remove all water from the tank(s) or you will have the same problem down the road.
 
Larger boats and commercial users usually have a 2 Racor setup so one is on line and the other can be changed or ready to take over w/o stopping the engine.
 
Most of the cases of this can be resolved by a few changes of the racor filters. Run the boat offshore to shake up the tanks, and change the filters when they get clogged. Have a helper take the wheel while you do the swap. Best to do with tank at 1/4 to 1/2 full.

Typically the first filter might last an hour, next one two hours, next one four, etc. Basically doing the same thing as a polishing company.

Any way to lance or sump the tank bottoms? Get the water gone and the bugs won't grow.
 
I would have a professional fuel cleaner come in and clean your fuel. You need a very high volume pump to keep the crap suspended so it will get filtered out. You can do it yourself but it may take a long time to get it all out.
 
I would not install the additional "screens." Instead do the polishing suggested above either by yourself or professionally. I would also recommend that you install a valved crossover fuel line downstream of the two Racors allowing you to run both engines off one Racor when the other clogs. Shut off supply to the clogged unit, open crossover, restart the shut-down engine, and change the affected filter before reversing the valve settings. You do have vacuum gauges on them, don't you? I did not have a shut-off valve downstream of my racors before the crossover, and I never had any trouble swapping a filter out/in with both engines running slowly, but just to be really sure you don't suck air into the engines while the clogged Racor is open, you could add them. Because of the mounting location of my Racors well about the bottoms of the tank, I installed a Facet fuel pump in the system enabling me to fill empty Racors or to keep an engine running when an air ingestion issue reared its ugly head.
 
As mentioned. you should add valving so you can run either engine off either filter.

I recommend installing a separate fuel polishing setup. Install another racor along with a walbro or holley fuel pump.

Are you using secondary filters or just primaries?
 
Based upon my experience with Irma, massive amount of rainfall, change the O'rings on the fuel fill and give serious consideration to installing a self contained fuel polishing system. First time 30micron, once you get all the big pieces and water out, change to a 10micron filter, polish all the fuel a few times.
My fuel polishing system is made by the same folks who make your oil change system, Reverso. They make a "clean installation", pump, single protected filter, and electronic to you can schedule when for how long to polish the fuel. I have the smallest system, the down side is, the smallest system uses proprietary filters. The larger system, I believe, use a standard Racor filters.
With proper valving, you can run off of one tank and polish the other, run off both tanks, polish both tanks and or transfer fuel between tanks.
 
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I recommend installing a separate fuel polishing setup. Install another racor along with a walbro or holley fuel pump.

Those fuel pumps are great for filling filters and bleeding injection systems but the flow rate is not adequate for polishing. Polishing systems typically use gear pumps with at least an 80 GPH flow rate to agitate the crud off the bottom and the far corners of a fuel tank.

I installed a polishing system on Sandpiper after purchase.

I cleaned the tank throughly and reconfigured the fuel tanks to be bottom feeders, to facilitate water and contaminant removal from the tanks sumps. I only purchase fuel from a ValvTect dealer and test for water monthly. I have not detected water in the tanks in 20 years..

I found that I didn't need to polish the fuel on any regular basis so I removed the polisher and sold it on eBay.

I think built in fuel polishing systems are oversold. To actually polish the fuel to get rid of the crud, access to the interior of the tank is required. A wand is used to wash the crud off the tanks interior walls with recirculated filtered fuel. The dirty fuel is picked up and pumped through the filter.

After installing the Reverso 150 GPH polisher and running it for several days, I pumped the fuel into barrels and opened Sandpipers tank access plates and looked inside. The tank walls and baffles were covered with little black specs. The tank bottom was clean around the fuel pick up and down the center. The black specs were stuck hard and required scraping off with a plastic scraper and washed off with diesel sprayed out of a wand.

I ended up connecting a Racor 1000 to a 200 GPH gear pump with a hose and wand to get all the crud off the walls and baffles. Went through 12 elements.

My tanks were 24 years old at that time and were not that bad. My engine never stopped due to a clogged filter.

Unless you want to go through all that, hire a fuel polishing company or rent a polisher.
 
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Larger boats and commercial users usually have a 2 Racor setup so one is on line and the other can be changed or ready to take over w/o stopping the engine.

My AT34 also known as, 'my little bitty boat', OEM is a duel Racor and vacuum gauge on the ME and the gen is a single element Racor. I too recommend a duel Racor on the main engine. I guess if I were paranoid, I would have a duel Racor on my generator.
 
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Greetings,
Mr. CS. Algae does NOT grow in fuel tanks BUT there are microorganisms that do. The "bugs" need water so you must have water in your tank(s). The Killem did it's work and killed all the bugs and that stuff that's clogging your filters is dead "bug" bodies (bio mass). As suggested, you can have the fuel polished or make your own filter type system. In any case, you must remove all water from the tank(s) or you will have the same problem down the road.

I split a bottle of Killem between the three tanks. We pumped out 460 gallons of bad diesel and several gallons of water too. I added 4 bottles of Stanadyne Performance Enhancer and put 240 gallons of new red diesel in. After the first trip on a choppy day the slime balls were clogging up in the bottom of the Racors. The 10 micron filters in the Racors were clean because the trash was too big and would clog up the float ball in the bottom. It was starving both engines of fuel.

I need some kind of screen first that will let the small particles in to the Racors but one the will catch the big pieces before they get to the Racors.
 
I have one Racor per engine. 10 micron elements
 
We tried a polisher several years ago and it didn’t get all the crud out. It just broke it up and sent it through the Racors
 
My AT34 also known as, 'my little bitty boat', OEM is a duel Racor on the ME and the gen is a single element Racor. I too recommend a duel Racor on the main engine. I guess if I were paranoid, I would have a duel Racor on my generator.
I also have duel Racors on the mains and I am paranoid & have decided to put duels on the jenny as well.:blush:
 
I also have duel Racors on the mains and I am paranoid & have decided to put duels on the jenny as well.:blush:

Put a vacuum gauge on the duel installation of the gen too.
 
Put a vacuum gauge on the duel installation of the gen too.
That's the plan!
The duels on the mains have a gauge with a tattle tale.
 

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And that is why I gave my Racors away, that is, the float ball can and sometimes does clog up and restrict fuel flow. Filters changed, fuel lines changed all to find out that crappy little ball was the culprit. Install a Tony Athens filter system and never have to worry again. Way less expensive also.
I split a bottle of Killem between the three tanks. We pumped out 460 gallons of bad diesel and several gallons of water too. I added 4 bottles of Stanadyne Performance Enhancer and put 240 gallons of new red diesel in. After the first trip on a choppy day the slime balls were clogging up in the bottom of the Racors. The 10 micron filters in the Racors were clean because the trash was too big and would clog up the float ball in the bottom. It was starving both engines of fuel.

I need some kind of screen first that will let the small particles in to the Racors but one the will catch the big pieces before they get to the Racors.
 
There was a very informative thread on this subject on the downeast forum last week. Many commercial guys use a product call AJX. It basically dissolves the bacteria (not algae) without the precipitate problem. Google the product - there are several videos.
 
Greetings,
Mr. CS. OK. So you've already had the fuel polished (post #15). You either had a bad polishing job or you've got an ongoing water contamination problem.
 
There was a very informative thread on this subject on the downeast forum last week. Many commercial guys use a product call AJX. It basically dissolves the bacteria (not algae) without the precipitate problem. Google the product - there are several videos.
I Googled it and here is a video.

 
Greetings,
Mr. CS. OK. So you've already had the fuel polished (post #15). You either had a bad polishing job or you've got an ongoing water contamination problem.
Sounds to me that RTF has it right! Definitely check for water and stop any leak (sources) or this will continue.:eek:
 
If the deposits are "large" then you can add this fuel strainer to your system.
https://www.parker.com/Literature/Racor/14401_Rev_-_PS120_Series.pdf.

That's what I have installed on mine as a "pump debris safety"..The advantage of this approach is that the fuel quality can be seen at all times and the strainer bowl can be removed and cleaned when the strainer is clogged. It's a rather large mess so it will only remove the larger debris, leaving the filters to deal with the smaller stuff. This will reduce the filer changes and save money - in addition to a safer system.

I think this product will do what the the OP asked about initially.
 
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In the past the fuel strainer consisted of a 1 quart glass jar with a cloth sock .

The water would not go thru the special cloth , and form droplets in its surface .

When the drops were large enough they would fall to the bottom of the jar.

When ever the water & crud became deep enough , the engine would be stopped , or fed from a different source, the glass jar simply unscrewed and contents dumped into a pail , reinstalled and when the supply valve was opened, fuel filled the jar, the last twist tightened it ,which bled the system.

Very simple and worked well for boats with no sump in the fuel tank.
 
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