question re: cold water reef

[toonces]

hi guys,
i didn't want to hijack your other thread.

for cost reasons, i may need to convert to a cold water reef...see here- http://www.reefcentral.com/forums/showthread.php?s=&threadid=1022604

if you want the details.

if i do this, i intend to run the tank at 55-60F.

i have one major question. right now the tank is running as a tropical reef. been set up about 3 months. if i sell off everything but the live rock, will the live rock be useful in a tank at 55-60 (provide any biological benefit), especially if i cool the tank over a 2 week period? what i mean is, if i bring the temp down a degree a day for two weeks to 60F, will organisms survive to make the live rock worth keeping for filtration? if not, i'll get basaltic rock that will look more authentic and sell off the live rock.

thanks,
mike

 

[mr. bojangsjang]

The LR won't be of any use in temperate tank.

 

[birdfish]

To take this train of thought to a ridiculous end, one of my specialties, I would think if I took saltwater live rock and put it in a freshwater tank after the "salty" bacteria died it would be recolonized by freshwater versions of the various bacteria in short order. Therefore, I would expect if the species of "good" bacteria that live at tropical temps died changing to temperate, it would not be long before the bacteria that do live at the new temp would colonize, just as would happen if the rocks were put in freshwater. Conversely if we took rocks out of a freshwater tank and put them in a salt tank, would they not be colonized by the appropriate bacteria?

birdfish

 

[mr. bojangsjang]

Sure if you took SW LR it put it in a FW tank it would become colonized by some FW bacteria, but it won't even compare to a filter. This is why we use filters in FW tank as the filter media is constantly be run over with water (as decor is not) thus making the best place for bacteria to colonize.

if we took tropical LR and put it in a true temperate tank (eg temps no more than 56, not subtropical) the bacteria would die along with the hitchhikers. Whether enough denitrifying bacteria would colonize on the rock would be the question, but I doubt it.