>>> MY PERSONAL EXPERIENCES <<<
It is a losing battle to fight a fungucide infestation with the factory-style fuel-filter alone.
None of the biocides are really very effective in a genuine infestation, as the bacteria that survives thrives exponentially on the dead carcasses, making the situation worse.
Steaming the tanks is about useless, except that doing thus also gets rid of a lot of non-bacterial crap that is also floating around in there.
What I have done that DOES WORK :
Install a GoldenRod sediment-bowl/pre-filter unit as the first line of defense.
Second in line, install a glass-bottom LUCAS water-separating sediment-bowl.
Third in line, install a New Zealand De-Bug magnetic fuel-filter; this kills the "algae" and keeps killing it forever.
Fourth in line, install a simple see-thru in-line filter just ahead of the lift-pump screen, catching anything that would otherwise lodge in the screen; this filter is a lot easier to access/replace/trouble-shoot than tearing into the lift-pump.
Fifth and last is the main fuel-filter in the factory location.
So far as keeping the engine running, without frequently clogging the main fuel-filter, the GoldenRod is the best line of defense, as anything of any size sufficient to affect running of the engine will settle out in the deep see-thru sediment-bowl and go no further; the expensive main fuel-filter lasts many many times longer with the GoldenRod doing all the dirty work.
The De-Bug magnetic "killer" unit prevents the acid-causing increase of "algae" production, thus preventing the subsequent internal rusting of the fuel system.
The water-separating LUCAS sediment-bowl is clear glass, thus I can actually see when it has caught any water; plus, it has a much deeper water holding capacity than that capable with the highly insufficient factory-style filter.
Since installing this barage of filtering devices, I have not had a single issue with "algae" infestation.
In twenty-five-plus year old tanks, often having to fuel in seedy-looking places, there is most likely still plenty of "algae" within the dark confines of my cavernous tanks; but, it scares me not, as I have full confidence in my fuel cleansing system.
Like someone has already stated, it is improper to call it "algae", as it cannot be "algae"; but, like the common un-educated mis-use of the term "point blank range", the name, although wrong, has stuck.
........................................
"Point blank range" is that spread of distance in a projectiles trajectory upon it's
SECOND crossing of line of sight, when the projectile is no more than one-inch above, nor more than one-inch below, point of aim.
The flatter the trajectory, the longer this point blank range.
The term has nothing whatsoever to do with shooting something up close, regardless of how cool it may sound to un-educated ears in a hollywood cop flick.
Now you know.