New Live Rock vs. Old Live Rock

[mikenegue]

Does it make a difference whether live rock is purchased from a store (which procured it somewhat directly from the ocean) or from another owner who had it in his/her fish tank for some time?

I'm trying to seed some dead ocean rock and dead sand with some live rock. I assume that live rock from either source would have beneficial bacteria, but will second-hand live rock also come with critters lurking under the surface? Also, could store-bought live rock have bad critters that are absent in used live rock?

NEW live rock or OLD live rock -- is one better than the other?

 

[Anonymous]

It's a toss up my friend....seems like there are no easy answers in this hobby. :roll:


The old live rock will have plenty of the bacteria you want and several life forms that will colonize your dead rock and sand, but, having been in a tank for (you didn't say how long), many of the life forms will have become extinct....so only the surviing species will make it to your tank.

The new love rock will be fresh from the ocean...assuming it is a good source...and it will contain more diversity, which will spread to all the rocks. And as you know, more diversity is better.

Example: My system has been put together for two years, I have been the owner for less than a year. The rocks had plenty of corraline and lots of copepods and amphipods. In the last 6 months, I noticed a reduction in diversity, not numbers, just diversity. Some of the amphipod species seemed to be missing. Possibly less equiped to survive in my tank.
So I bought ten pounds of premium live rock and added it to my tank. Within two weeks, I have seen a huge bloom of little copepods, amphipods, and a few brand new species of algae munching isopod. Deffinately worth the purchase of the new rock.



On the down side, your new rock can bring in a mantis shrimp or an evil crab. My new rock brought an evil crab that is the size of a pencil eraser. Small now, but he will be trouble before 2005 is here. :roll:


Still, you should seed the old rock with just a few pounds of new rock, just for diversity's sake.

Good Luck!