Black debris in my spare diesel containers...?

[johnandrews]

Recently I checked my spare (full) diesel conatiners and saw some black debris on the bottom of the containers. There wasn't much in each container but I filtered all the diesel again and one by one thoroughly cleaned each conatiner. I had added some diesel additive to each conatiner when filled (about two months ago).the containers were filled at the same time as the boat at a busy fuel dock in Grenada (carribean).

Does anyone know if the debris was.......
Harmless?
Water? Nb. No water was retained when i filtered all the fuel again.
Diesel bug?

Was it necessary to refilter and clean each container?

Thanks
John
Currently sailing Wizard and anchored in Jolly Harbour Antigua.

[Lepke]

I had a similar incident with a 5 gallon portable diesel can. After using the diesel, the can was put away and at next use I noticed black flakes in the bottom after I had started filling it. I think they were an organism that grew from condensation and the little fuel left in the can.
I added a diesel biocide and when I used the fuel I strained it. That seemed to fix it.

[cal40john]

My guess is asphaltenes.

Fuel School: Asphaltene's and Plugged Fuel Filters

[CrustyChief]

Originally Posted by cal40john

My guess is asphaltenes.

Fuel School: Asphaltene's and Plugged Fuel Filters

Thank you for the link, good info!

[roland stockham]

Normal in the Caribbean. any fuel left in containers or the tanks will grow bugs, Its the penalty for all that nice warm weather microbes love it too

[hamburking]

Originally Posted by roland stockham

Normal in the Caribbean. any fuel left in containers or the tanks will grow bugs, Its the penalty for all that nice warm weather microbes love it too

Instead of an expensive biocide, could I just put in a few ml of gasoline into each diesel can?

I've read that gasoline is a good biocide (here on CF).