well said Steve. Its true... if the goal for a given coral is maximum growth, then monospecific culture is the only way. Its a huge difference if you will see/take the time to run comparative tanks (trials) between mixed cultures and monospecifics)
I just posted this on another message board with a similar thread:
whole thread:
http://forum.marinedepot.com/Topic53146-13-1.aspx
excerpt:I often sound rather strict/purist about the crowding or keeping of mixed coral tanks... but truthfully, I not only recognize that most folks have these tanks... but I also have enjoyed some of my own this way (and will set up tanks in the future as garden reef mixes).
The root of the issue is that any of the corals we keep if left alone could fill out aquariums in just a few years. If they were on the reef... they'd gobble up that tiny patch of space fast.
So in our aquariums... more than a few corals mixed together is indeed "too many"
But we are not going to change our heavy stocking styles any time soon.
My suggestion is that we can all enjoy these types of aquariums a bit more successfully if we compensate for the compromise (crowding).
You'll see that aquarists that change carbon frequently (weekly ideally in small portions... but at least monthly strictly) or use some other chemical media (ozone ideally)... those that do their water changes, know how to tune their skimmers and then actually keep them producing skimmate near daily have little to no problem with garden reef aquaria.
It is when we get lazy (as many folks do) and a number of the necessary husbandry reqs are ignored that we start to see mysterious deaths that are not so mysterious
With good husbandry, I'd still never recommend more than 1 species per 10 gallons. Even that is a rather poor rule over time (deaths will still occur that could have been avoided)