I think your conclusion might be a bit hasty. Of course it could be that you have a specific species that exhibits this behavior too.
Calfo talks about a few different aspects of Xenia prorogation in Vol 2 of his book. The part that is applicable to this discussion is his observation about pulsing behavior slowing and eventually stopping at pH levels below 8.4. He always maintained his pH at 8.4 or above as a result and was producing thousands of small colonies a month. It would be difficult to imagine that pH being maintained without high alk.
The only thing that is a limiting factor to xenia growth in my experience is low levels of dissolved organics, the cleaner the water the slower it grows. I think this is probably also a factor in your observations because I bet at those higher alk levels you were seeing faster stony coral growth and more importantly higher coraline growth both of which would have an impact on the dissolved organics the xenia needs to fuel it's growth. It was just getting out competed.
Did you noticed a difference in coraline growth with the higher alk levels?
|