Dendrocare Medium was developed for the more advanced private grower perhaps owning several frogs. A handy package that makes for a slightly larger stock of Dendrocare. Put a pinch of Dendrocare in an empty jar, toss in the fruit flies and shake. The powder securely stays on the flies. Place a lid in the terrarium and sprinkle the flies on it, surviving deposits of the Dendrocare will remain.The useful life naturally depends on the intensity of use. In the above instructions Dendrocare has an average useful life of 30 d..