Does alkalinity affect the color of SPS corals?

[hambalid]

It was mentioned in passing by my friend that alkalinity (dKa) can affect the colors of SPS corals.

Being skeptical of this, I've searched around and haven't been able to find anything either way. I had always assumed that lighting promoted pigmentation and calcium/alkalinity promoted growth.

I'd like to see how the more experienced members weigh in on this topic.

Thanks!

dan.

[Boomer]

Yes it does. It is pretty much spelled out here as best as one can do.



http://www.reefcorner.com/Manual/sps_coloration.htm

[hambalid]

Thanks for this excellent link, Boomer!

dan.

[Boomer]

OK, so before Randy gets here I get to " beat" him to the punch

You're welcome :D

[Randy Holmes-Farley]

:lol:

I'm not sure that I believe that there is that much of a link, however. Quite a few folks have not noticed such a correlation.

I'd suggest reading this FAQ from Eric's forum:

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=234253

from it:

Q for Eric:
"A while back, there was a hypothesis going around that suggested a correlation between coral coloration and alkalinity levels. What's your take on that?"

Answer by Eric:

"well, a hypothesis is a tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation - as far as I know, this hypothesis has never been tested, and remains a weak anecdotal observation...

my feeling is that higher alkalinity spurs faster growth and hence longer growth tips that are low in zoox but high in pigment, lending the appearance of being more colorful. Personally, I don't think there is any correlation between the two."

[tatuvaaj]

And let's not forget that corals have pretty nice colors in the nature with alkalinity around 2.5 meq/l ;)