Because true bogs are very low in O2 and nutrients they tend to smell little. Sure if you disrupt the system they can smell but my bog has been established since 1998 and it has no odor except a wonderful earthy smell.

It also depends on the sort of bog you have in mind. Mine is fashioned after a true boreal bog. adding nutrients or any sort of fertility would kill most of the plants I grow and would certainly affect the smell. Once you establish a mini ecosystem an equilibrium will establish itself and odor shouldn't be a problem.

Make sure you mix some sand in that peat and saturate the mix with water BEFORE putting it in your water filled container. Over-fill the container w/ your mix (unless you want some standing water) and it will drain over the sides. You could also put rocks or sand in the bottom before adding the mix depending on the depth of your container.

Fred is right, my bog has no smell either.