I am by no means an expert, having been the proud owner of a new water well about 6 weeks. However in our area the secret to getting rid of most of that smell is to expose the water to air. That doesn't happen if you have a bladder tank, as the air in the tank never touches the water. The bladder tank is designed to prevent waterlogging (where the air in the tank gets absorbed into the water), but if you have a sulphur smell the water needs to make contact with the air. This means a regular old galvanized tank with alternative measures to avoid waterlogging.