Is coral covered live rock still a viable filtration media, or a nutrient trap ?

[straightrazorguy]

I find it surprising that nobody mentions the coral's nutrient uptake. Corals (andby that I mean zoas too) use up nitrates and phosphates to grow. So, if anything, they help the nutrient equation. Sure, there's less exposed rock to harbour bacteria, but one can add rock elsewhere in the system: a refugium, cryptic rock in sump, etc. There's also tons of bacteria in the sand. Why would you want exposed rock in your DT?

I vote for coral-encrusted rocks over bare rock any day....