No chance for flies or insects.
Root balls are completely sealed from the outside
If used correctly, the Hydro Farmer protects the root balls 100% from all kinds of insects.
The lid prevents the hydro Farmer of insects intruding from the top. Depending on the implemented system the bottom of the Hydro Farmer can be sealed with a thin water layer or by placing it on even ground.
Assuming that the used substrate is insect egg free, it is excluded that the substrate becomes a hatchery for insects.
A hygienic advantage for the user is, that it can be refrained from using pesticides or fungicides.