How often does every1 use DE? We r having a real prob with flies this year. We have had a lot of rain and water is laying in the field near the chicken run. I was wondering how often it is safe to sprinkle the run and the coop with the DE. Also, if we use the DE do we still use the liquid wormer in their water? Just wondering how effective DE is for worming. The girlies have been out in the coop & run for 1 week. They r 8, 9, & 10 weeks old. Thanks!!