Tony When the process was finished after the second stage I checked the bio with a test strip and it showed that the acid had been neutralised so I hope there was no residual acid left in the whole of the liquid. However I think I started to wash this batch too soon after processing because I read on the net that a Mr Lyle waits for at least three days to let it settle before washing commences. too anxious to get it washed it has turned cloudy so I'm going to look into making filters to filter it dry. Thanks Regards Mick