Yes, the drip takes away the need for massive filters.
I simply run cover glass on my sump, same as the tank and I do not get any evaporation or humidity, I am shocked by the number of sumps sold without covers. My friend recently bought one in the uk and it came without, this could ruin a stand within a few weeks.
I have cut Perspex around where the pipe work exits to stop any extra evap.
Glad the heaters are in the overflows.
I though of the same idea to cover the base of the tank but I assumed it would be abrasive...keep us updated!