Megathura crenulata   2/8/11
Hello again, good folks of the WWM Crew,
<Lanny>
Thank you again for all your help, time and time again. I write today while in the process of setting up a coldwater system for housing *Megathura crenulata* - the Giant Keyhole Limpet.
<Oh, yes... have collected and kept>
It's habitat includes kelp forests and rocky reefs of southern California. I would like to use aragonite sand and rock in the tank for it's buffering capacity as well as its porosity.
<Sure>
I am wondering if this will affect the recruitment of organisms substantially, seeming as our coast is composed of shale, diatomite, basalt, etc., all of which are extremely dense and have no buffering capacity. I could use (legally) harvested coastal live rock in the tank but I would much rather seed and cultivate some sort of calcium carbonate base rock.
<No worries either way... I take it this system will be chilled>
Will this fly? I tend to think that in time, the biofilm and algae cover would obscure any effect the different base rock composition would have, but I also tend to fall down when walking up stairs, so I take my opinion with a grain of salt... I much appreciate your thoughts.
Thanks again,
Lanny Flaherty
<Bob Fenner, in the process penning a pc. for AFM/FAMA's marine annual re coldwater Pacific systems>