Is it real live rock?

[GuamSalt]

Hi,

I'm out here on Guam and have two 12 gallon Nano's. I've upgraded the light to 48 watts. Recently there was a power outage and I lost both so I'm starting up again. I returned my old live rock to the sea and found some new rock that really looks great. Some thousands of years ago, when Guam was an active volcano, lava poured into the ocean, wrapping around the coral that was on the fringe of the island. A lot has broken off and can be found on some beaches. The rock is dark and quite dense although it doesn't seem to have become basalt. The question is whether this stuff could ever be good live rock. Much of the rock seems to be dense enough that it would never absorb sea water.

Many of the discussions of live rock seem to be based on the assumption that anaerobic bacteria live inside of the rock and help the aquarium deal with the build up of nitrate. The question is whether that is correct, and if it is, then would this kind of volcanic rock ever be able to serve as real live rock?

Guamsalt

 

[melosu58]

The ideal situation is to have a pourous rock with lots of holes so as to have more surface area for the bacteria to be at. It will still thrive on a flat dense surface but just not as much as pourous holey LR. As far as the chemical make up of lava rock I`m not sure if it can be used in a small aquarium setting. Maybe someone with experience with this type rock can help.

 

[roka64]

I read a post, not long ago, that volcanic rock can have heavy metals in it and is best not used in SW tanks, but like mel said, I would wait for more experienced folks to chime in.

 

[Devilishturtles]

If the rock is inert, I don't see why you can't use it. But like melosu said, pourous rock is ideal because it allows more space for bacteria to take hold, the nitrifying bacteria that help the nitrogen cycle and break down of ammonia into nitrate.

I visted Guam two years ago and saw the rock you are talking about. I joked about packing it up and bringing it home to put in my tank because it looked so good. Nobody mentioned to me that I shouldn't (of course, I didn't, but they still didn't say anything). I think as long as you are sure the rock isn't contaminated in any way, then it'd be fine to use in your tank. Of course, I'm not a geologist though, so I couldn't say 100% one way or the other.

Welcome to AA

 

[melosu58]

Where are my manners. Welcome to AA

 

[roka64]

Me too!


WELCOME TO AA!!

 

[hc8719]

its lava rock then? ive read that only once living rock (corals) are appropiate for sw. they did an experiment, made some porous rock from tar and other materials, and then tried to grow bacteria on it like real LR, and it didnt work.

"real" LR has calcium, and nutrients that bacteria need apparently

 

[ntswift]

If there is some kind of geological report on the lava in your area you could check the metal content in it. Maybe the library might have something? I agree with mel and Roka that you should becareful of the metals that you are introducing into your tank. Copper can have add a really bad swing to things. I would hold off for now until you got some more info on it. HTH.