I prefer kelp for the minerals, I use a combo of regular kelp along with another that is higher in potassium, since kelp is higher in sodium WHICH YOU NEED, natural sodium, and the others are higher in potassium.
After supplementing with those for a while I added a drop of Iodine slowly...kelps help more with the adrenals and have vitamins/minerals so I try not to use a lot of natural Iodine since it is an isolated substance! The problem with that is that it takes a lot of kelp, versus smaller amounts of the Iodine so I use both!