I use AHE cinch buckles and webbing for the suspension and before I got a quality (nylon) tarp, I used to used a poly tarp, I had a small section of paracord wrapped around the webbing in a prusik knot on each end to which I would run a ridgeline from end to end. Then I would feed a loop through the grommet and insert a twig in each end. When the tarp was in place I would slide the prusik knots in opposite directions to tighten the ridgeline, which would tighten nicely even while in the hammock. Today I used the cinch buckles and new tarp in the same manner but when I got in the hammock the ridge sagged down. I could not make it any tighter. What am I doing wrong and what should I do?