Sorry to post in an old thread. But I was wondering, do you think that your plant grew so big because of the roots swimming in the DWC cooler? I have previously read an interesting theory that it is when the tap root hits the bottom of the container that the autoflowering kicks in (although thinking about it, this would not work outdoors).
But, if the tap root is swimming around not hitting the bottom, it may postpone autoflowering enough for the plant to grow mahoosive!