I've heard that softies and lots of lps make it hard to keep sps in the same aquarium
You say you aren't getting good growth and in the same sentence you said they were fully encrusting the plug?
You say you aren't getting good growth and in the same sentence you said they were fully encrusting the plug? To me growth is growth.
You could try cutting off a few tips and seeing if that helps.
I would say this is the most intelligent answer/ recommendation to the OP, you have had them 6 months so they are stabilized and can hold up to a few snips.
In the decade+ I have worked with SPS, I have found cutting/ slightly damaging tips of "stagnant" frags or even individual branches that dont seem to grow, while the rest of colonies' the branches take off can successfully spur new growth, particularly in the genus of Acropora.
I like to take a fine icepick and gently tap the dead center (mouth) of the axial corallite on top of the branch, basically gently crack/shattering it to the point where it still stays together/ regrows. I have found this method produces more new branches than simply cutting the tip off with bone cutters.
I've always wondered if there is scientific evidence to support this claim? Is increased growth rate a defense mechanism of some kind to damaged corals or simply a healing response that detracts from the overall growth rate by a repositioning of it's resources? Is it a matter of perception or is there any truth behind it? I know if I break a piece I will see it heal, and maybe if spawn new branches but when something is healing or encrusting it's easy to measure changes. I can't say for sure if it's a perceived increase in growth or if the coral has actually been stimulated.
If there is nothing obviously wrong, our corals will keep growing. The best way to tell is just by measuring your consumption of alk/calc. There are many times I think specific corals aren't growing however when I compare pictures months apart I see that they are.
While I'm not trying to refute this claim. I'm wondering if there is any evidence to support it, or is it simply a matter of perception? I can see it making more sense with larger colonies where fragging your coral will allow better light/food penetration to the original colony and the frag if it were starting to stifle it's self but I am not so sure with frags.
My evidence is reading about the method in calfos book of coral propagation and in volume 2 of sevin A Fossa and Alf Jacob nieslens "the modern reef aquarium" series and then successfully seeing it work wonders for "stagnant" frags in many of my clients aquariums and my own as well.
Scientific evidence?? Ain't nobody got time fo dat !