Hi TripleJR. First, stand right way up! Not easy to stop Cardon growing, as they are very tall in nature; it's a bit like trying to subdue a palm tree. I see you have it in a fairly small pot, whch should limit it somewhat. Any drastic methods, such as root-cropping or cutting the plant in any way will spoil its health and beauty. In captivity, it probably won't grow more than, say, 8 to 10 feet?
Cardon is a bad choice for an indoor cactus, unless you have cathedral ceilings...you barrel cactus neighbor is far better. Of course, your cardon can go outside later if you live in a warm, sunny area (no frosts...will kill him!). Good luck! Bob