They can be pretty much anywhere except the very top, but in my experience they do best on the bottom. He seems to be growing just fine wherever you have it in the tank now though. It will tend to have a half moon appearance. When it gets larger it will probably irritate if not kill your candy cane next to it and if it were me I'd frag the candy cane and put them somewhere else. It doesn't look like they are interfering with each other right now, so maybe give the candy cane some time to get good and healthy before you frag it. The stalk will break pretty easily and you can just glue them to another spot. That has just been my experience. Others may want to chime in if they have other advice. :bounce: