Acans: mount or not?

[bmackcw]

Quick question - I have a few healthy acan colonies. Two over growing their frag plug, one that I glued to a rock about a year ago. Does it matter if they're mounted on a rock or will they grow just as well in the sand bed?

 

[Potatohead]

Nudge a rock up beside them so they can grow onto that. They'll grow on sand but only if they absolutely have to, they tend to keep building their skeleton upwards when they hit sand.