yeah I see a problem... no fan
forgot about that, thats the "problem" ideally the fan would be inline... which Im not sure a water proof fan exists for the application.
since its open on both sides, you cant have a 3rd point to blow in as it would just blow down into the holding tank, not up through the mesh.
now you could seal it up top between the evaporating chamber and the holding tank. and blow into the holding tank, and up the chamber, and out. but then you need a seperate bubbler tank outside it.