I use a Harken Tune Tool. It is electronic, and reads in KG. It appears to have no accurate corallation to my old Loos gauge. In any event, I started out setting the shrouds to 112/70 for 10 knots wind. I set to 130/80 in 15 knots wind. I think I am now running less lower tension, basically just tight of slack. I don't actually adjust the lowers as the wind comes up, they get tighter just by having the spreaders push the mast forward against the lowers as the uppers are tightened.