On Sat, 08 Jul 2006 16:19:12 GMT, "Bryan" wrote:

His tank is actually very healthy. He doesn't have a jungle of corals but
the ones he has placed are doing very well. I wish he had a pic of it on
his site.


Yes the corals can be healthy and growing despite sub-optimal calcium,
I've done this myself, and had tanks with corals doing OK despite no
coralline at all. It just strikes me as a bit odd intentionally
keeping SPS corals in water with less than sea water Ca
concentrations, somehow I enjoy striving to replicate nature, and
think it's a good general principle. And I wonder a little about what
the margin of safety is in those tanks I suppose, how do you guarantee
your Ca stays stable at that 300ish no coralline level, or just dives
at some point, unless you have a buffer zone above minimum
requirements. Maybe I'm taking a simplistic approach, I just see
reefkeeping as trying to replicate NSW and maybe that's old-fashioned.
Hey, I measured my Ca last night out of curiosity, 380, could do
better IMHO. Acropora and a Tubastraea (that we recently brought back
from near death ex dealer) look happy though, me I'd like to see 400
in there if I do get in a numbers mood :-).

Steve