>What is the best pollen trap?
I'm sure I haven't tried all of them, and I'm sure there are new ones every day, but I've never seen anyone complain about a Sundance. I have the Sundance II since I have top entrances. It seems like when people buy something cheaper they end up getting frustrated and buying a Sundance anyway.
>And when do youput it on and take it off?
I think you'll have the best luck right after the main flow. The traffic isn't so bad (since the pollen trap will cause a traffic jam) and they aren't in need of building up like they are in the early spring.