Diesel Jello

[Rick D]

So, on a recent trip, I had some fuel issues. The fuel had picked up a bug maybe five or six years ago when I had to use diesel from a gas station while the dock was being rebuilt. It was a green-black organic goo. I used a biocide at shock level and "polished" the fuel with my own hand made system using the tank sending unit hole for access. Worked well; problem solved.
The fuel dock reopened using Valve-tech fuel. They recommended I not use additional additives. Last year I only put about 25 hours on the engine due to boat work upgrades. It averages 150 hours. So, this leg of a recent trip, after a few stalls, I pulled the (newish) primary filter and emptied the contents into clear plastic glasses. I came across a big glob of clear jello-like stuff but none of the old organic-looking stuff. Changed the filter and continued the trip (with some spares!). Anyhow, I ran about 50 gallons of fuel through the rest of the trip. Changed the filter once and it was clean.
So, any thoughts from you petroleum engineers out there on what this was & the cause? I am reluctant to follow the same course I did before not knowing if this is organic or not.

 

[NYSail]

I am on the side for using your fuel to almost the bottom before putting new in and never putting biocides in.

 

[Calif. Ted]

Rick I ran diesel equipment here in SoCal and never saw anything but the green-black algae, heard that diesel will gel at low temp, (17 degrees) but we know that didn't happen unless you took the boat to the mountains. We get Valvetech also but my mechanic insists I add cetane booster, mostly for coking in the exhaust.
I did see a bunch of 5 gallon Valvetech cans at the fuel dock once, I'd assumed it came premixed from the distributor but they told me they added it by hand on delivery. Now my only wild ass conjecture would be that someone screwed up mixing additives in that batch of fuel either at the refinery, distributor or the dock.
I did take a 2 stroke class at OCC and the instructor said he'd seen gell form in 2 stroke tanks when some oils were mixed, presumably additives that congealed.

 

[thinwater]

I would bet that poor mixing was the problem. I've tested many of these additives, and if you just pour a lump in they can jell and go to the bottom of the tank. I never pour additives in the tank; I add them to a jerry can, fill it, which provides good mixing. There is really no obvious proper way to blend additive at the station. The best realistic possibility would be to load it into the tanker as it is filling at the rack.

You may have gotten anywhere from no additive to 10 times too much.

Is there another fuel dock? These guys are obviously ill-trained.