HooKooDooKu
Aquarium Advice FINatic
The bottle of Prime has a smell <when you open it>, but it is not that strong. Once you add it to the water, there is no smell at all.
BTW - most conditioners use the same sulfur compounds, you can't smell them simply because they are really diluted...
ditto
In the case of Prime, you are only adding two drops per gallon. From the moment I use the stuff, I've never noticed any smell. You are only using enought to offset the very small quanities of things like chlorine in tap water. Can you smell the chlorine? Most of us would answer no, so the same will go with the sulfer in these products.