Brittle skeleton on tank grown sps?

[nashorn]

Is it just me or anyone else notice that the frags grown in tanks have softer skeletons?
My tank raised one would snap off in my hands while any portion of original frag would be hard to cut with bonecutters.
I mentioned this at my lfs and the owner says he can tell where the SPS tank grown portion starts while using a frag saw.
Anyone experience this?

 

[Ocelaris]

Sure, we have probably a tenth of the flow that an ocean has, like a tree, wind makes their bones stronger. This article implies as much. Calm waters, brittle frags, heavy flow, stringer frags. It's also the species, a red dragon will never be as string as a stag horn type. I've heard the only definitive way to discern species is with skeleton analysis under a microscope, similar to mushroom identification.

https://reefbuilders.com/2017/09/21/acropora-plana/