Just had this pointed out to me and got me thinking. I thought as the suregrow doesn't contain mag ox I could add it, or is that not how it works? I don't feed anything else to mix the mag ox in with.
Well, there is no definitive answer to say mg competes seriously with other minerals, maybe calcium but there are so many pathways its hard to come to any sort of conclusion... In horses anyway. I don't think you will be dramatically altering the balance of suregrow by adding magox. A little at a time.