Mounting surface for frags or colonies

[ts47]

I am finishing the aquascape for a 120 mixed reef, my first tank. Does it make a difference if you mount frags or colonies to a shelf like srurface or the irregular surface of Marco rock? I have enough shelf to cover up some rough surfaces that are already level if not actually flat.

 

[blaxsun]

I find the gel glue works really good for odd surfaces.

 

[Propane]

Flat surfaces are not required.