Algae and bacteria grow in diesel fuel only when water is present.
. You should always store your motorhome with a full tank of diesel fuel. what happens when a diesel tank is not full. You will get condensation from the tank heating and cooling during the day.( just like a cold glass of water in a room. moisture condensates on the outside of the glass. well your diesel tank does the same only on the inside.) you need to remove the moisture in your tank. drain off a few gallons of diesel from the bottom of your tank. Water sits at the lowest part of your tank. Water is heavier than diesel so you will drain the water off first then the diesel. There is a product from Terraclean. Called TerraDiesel Fuel Treatment.
it will remove the the rest of the moisture in the fuel tank.
it converts water H2O into a Hydrocarbon and gets burned up in the engine.
I do not work for or have any financial ties to this company. I am a retired heavy duty mechanic for a large city in Canada. We had problems with algae in our fuel tanks.
this company came in and cured our problem.i now use it in my diesel m/h.
once the water is out of the fuel tank your algae problem will go away.
you can also put methol hydrate ( 1 liter)in you fuel tank to help remove the water.
remember to keep your fuel tank full.