oops..i meant i want to replace the 2 supers with a deep because the one deep is easier to maintain. thnx in advance.
It is not clear, what you have?
deep and low too?
Of course you do not loose anything. Put the new deep to bottom. When honey comes in, they fill supers from top to down.
What you have then? 2 deep and 2 low or?
When you have brood in 2 supers, the next emty super or more space must be located between brood and honey.
Garadully new bees come out from comp and bees fill them with honey. It takes a month or so.