Q:Where can I get hydrated lime? I'm trying to do everything I can for fly prevention and putting lime in stalls and in wet areas was recommended to me.
A: Hydrated lime, calcium hydroxide, (commonly sold as barn line - any coop or farm supply store should have it), increases pH. It can help reduce ammonia odor in barn stalls. It will also help absorb moisture, which may help reduce flies.
At amounts commonly applied (usually minimal amounts), it is unlikely to provide benefit for fly control. Maggots are pretty tolerant of wide ranges in pH.
If you are using lime in a pasture area, significant use of the lime may increase the pH enough to inhibit plant growth. Bottom line, lime does not directly control flies.
By Roger Moon, PhD, University of Minnesota