Ok so, just a little note to let you know that the Butt seems to be doing the job very well. There appears to be no leak from the tap!! There is a good amount of pressure on the seal at this stage given the amount of rain we had on Sunday. (The water is about 6 inches away from the top). I am really amazed at how quick the water fills in the Butt and am kicking myself that I didn't set up the Butt properly before now.
But sure, it's all in place now and is doing the job!!!!