Interesting subject!
How do you know you have a bacteria?
I have prefilter before main filter. Last mounth every 100km need to change it.
I have that on the tank from first day when I bought truck.
I removed tank once but did not succeedeed clean . that thing is very hard glued on the bottom. I tried to clean with everything what I had of chemicals. Hydrochloric acid.dimer,nitro thinner...
By the way I am mechanic for the boats, all boats with old metal tanks have this problems,no one with plastic.
my opinion is that can be a problem with condensation of moisture on the metal tanks.
I hope that!You know if that stuff on the bottom of your tank is so stable and immune to all those cleaners then it is very unlikely to cause you any problems. The 'sludge' that blocks up the fuel system is soft. The algaecide will not remove this soft/rubbery sludge but it will kill what is producing it. Thus once you clean out the soft stuff and use the algaecide you should get no further problems.