Have a good look at the picture above. It doesn't get any easier than that. Why take the time to drill a tiny hole in 1/4" tubing and risk the possibility of it plugging and then you are back to square one.

Just my 2 cents. Leon

Thanks to everyone for the suggestions and ideas. Because I had already run the line I decided that the simplist solution was to drill a small hole in the line as a siphon break. This seems to have worked perfetly - total time involved was less than a minute. Thanks Dave for the advice.

I hope it works out