Thanks for all the good advice. After all my first batch of fuel didn't end up too badly. Its now washed ok after I did a very slow job with it. It's a good job I re-read instructions by USA's biolyle who gives classes re biodiesel & makes plant etc. I was going to fine spray water onto the top of the fuel ('oops') which is in a conical HDPE container but he said he puts his water in at the bottom & then bubbles it gently for the first wash. I did as instructed with warm water (5%) which was very milky when drained & proceeded for three more washes & the last was virtually clear. I'll let it sit now as he says & then perhapse heat it to dry it (in case) & then hopefully it will be usable... Best regards Mick