My current work assignment is in Iraq and we experience similar problems described in past post on Diesel.
The best luck we have is to receive fuel in one tank, let the water settle out and then we filter with a typical fuel filter, nothing fancy or expensive. WE also add motor oil to our fuel, about 1 gallon ( approx 4 liters ) to every 1000 liters or so.
Since our fuel is cut with kerosene also, and the refinery's here are running too hot we get something closer to avaition kerosene rather than diesel, I suspect you folks have some of the same problems. Anyhow when you add motor oil to the filtered fuel, you solve some lubricity problems and also some timing problems associated with a high flash point on lighter fuels.
We do everything we can by gravity here, slowly, this seems to get rid of the water fairly cheaply and when you are using inexpensive fuel filters they are far more effective if you gravity fuel through them. Much the same as you folks in Indonesia, in Iraq we run of generators quite often.