I applied the solution to my seedlings after I saw infestation. I used the maximum as directed on the package because my seedlings were in distress. I applied every 4 days the first 2 weeks. After that, I only applied if I saw an infestation again. By that time, the seedlings were much stronger from being able to grow during the 2 weeks of treatment and after that most gnats were eliminated to continue to do anymore damage. One packet like above was more than enough to handle 200 seedlings. I might have overdone it with the application though. You may get even more use out of the packet.
