We have Hunter 18s. How do you tighten shroud tension. There is no turnbuckle, just a channel shroud adjuster, so nothing mechanical to tighten. How do you tension the shrouds. It looks a though the only recourse is to simply pull down on the shroud by hand and try to get the pin in as low on the adjuster as possible. There has to be a better way, but I can't see what it is. What do you do for this?