I have used two hose lengths of extension and had to increase the suction..but, I have not seen an increase in any bee mortality by increasing the suction. Be sure and not forget the piece of carpet on the 90 degree angle going into the top of the vacuum. Thanks on the word file....receive a PDF yesterday from a Beek, so I think I am good. Hope it works for you, like it has for us. A note on this, is that there are others out there that work as well or maybe better, but this style is very functional and inexpensive to make.