Not being an expert, but having some what of an experience with this, I am a firm believer in purchasing slightly larger pieces, never maricultured, but over the 1 inch frags if I can. There are two reasons for this- the first is the obvious reasons of "law of compound". Initial chunk of money, or "coral" up front WILL collect, and grow with much more "growth" ( in reef term) and "interest " (monetarily speaking) over time. If you started with a one inch frag with a couple of arms, as opposed to a slightly bigger with .. say... six to eight arms. Chances are, in six months from purchase date, you would have many more arms on the slightly bigger, and by then, who knows- you could have seeded off and fragged a couple for your buddies and still have a great looking piece without compromising the now " mini-colony". Now, the smaller one might be a little while longer before even the thought of " fragging " comes around.
Second, I read an article a while back discussing the survival rate of frags versus "larger frags" . ( sept/oct issue of Reef &marine aquarium Magazine, Article "How large should a coral fragment be?" pg 81) From what this article/ research states, larger Acropora frags survive and grow faster than smaller frags. That being stated, they also conducted multiple tests -of them, one was- frags glued underwater, as well as out of water. The survival rate of frags (2.5cm , or roughly 1inch) glued out of water had approx. 20% survival rate, where as frags slightly larger (3.5cm, or roughly 1.5 inch) had a survival rate of 80% or more. They also conducted the same test with same sizes, but glued them underwater, and both came out to near 90% survival rate. Now, I don't know EXACTLY which acropora specie they experimented on, but even in the home aquaria, I find that that rule generally applies.
