Thanks for great explanation.... super...

Yes I think tha`S what is happening... I have washed the Biodiesel a lot... and there is still a little soap ( or solified biodiesel . That`S what I think it is now ) when it is clearing up.. I warm the washed biodiesel to 50 degrese Celcius and then let it sit in a drum.... when I take a sampel of it , it is clear when it is hot in the air... and when the morning comes ( after the nicgt temp) it is a little cloudi.. so ot must be the biodiesel and not soap formation. Thanks for great answer that I have been concerned about it...

Gert