# Rock from freshwater or brackish aquarium



## karaim (Aug 28, 2008)

Hi. I have several questions regarding live rock.

First, my father has a freshwater and a brackish aquarium with rocks. The fish there have died (old age, not sickness), but the filter and lights are still on (he doesn't have time to dismantle it). My question is can I take some of the rock from those aquariums and put it into my new saltwater aquarium? If so do I have to cure it?

Second, I was in Mexico on vacation and found several large rocks in the ocean. I brought them home with me thinking I might use them in a saltwater aquarium one day. That was 1 year ago. The rocks have since found their way into the my garden and were covered with dirt. I washed them out thoroughly with the hose (with extra strong pressure). They look perfectly clean. How much curing do I have to do for these rocks? Is it possible that a strong current from a hose can get rid of all the dead bacteria?

Third, my father has a 10 gallon saltwater aquarium. The fish have died (again of old age) about 5-6 month ago, but the aquarium has some nice rocks. The filter has been working this whole time and the lights have been on, however there has been no feeding (because there are no fish). Is it possible that this rock still has some beneficial bacteria? It is covered with a lot of brown stuff.

Thanks in advance for your help.


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## Pasfur (Mar 29, 2008)

First, you are very lucky. Your father's 10 gallon aquarium is a perfect quarantine tank, and it is already set up! Just test the water for ammonia, nitrite, nitrate, pH, and alkalinity. I will want to do a 50% water change prior to testing. 

For the record, most fish have a natural life span of 7 years or more. It is extremely rare that a captive fish dies of old age. 

On the questions about rock, i think you misunderstand "curing". Curing is the process where living organisims on the live rock die, as a result of the rock being taken out of the ocean. There are some organisms on the rock that die in transport, and other than simply can not live in an aquarium. These are generally microscopic organisms and bacteria, some algae, sponges, varieties of worms, etc. For the most part, the beneficial living creatures survive, including most beneficial bacteria.

With this understanding, the rock in your freshwater aquariums and your garden does not need to be cured. It needs to be cleaned. I would strongly recommend that after cleaning dirt from the rock with a powerful rinse, that you place the rock in boiling water for 30 minutes or so. Then give it another good rinse. If the rock is porous, I would suggest placing the rock back into a bucket of fresh water as a final step, leaving it for a couple of days, and then testing the ammonia. You never know what is inside the rock that may die off.

For the record, if this rock is porous, it will likely be seeded by new live rock additions to the aquarium and eventually one day become "live" itself. It the rock is more smooth in texture, then it will never really have any biological benefits to the aquarium, although it may be used as decoration or as a base for the other rock. Bottom line, the more porous the better. I personally use both tufa rock and lava rock as a base for live rock.


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## karaim (Aug 28, 2008)

Thanks Pafur, that helps a lot.

You're right, I misunderstood what curing was. Thanks for clearing it up for me.

Where do you get your lava and tufu rock? I tried to find it online, but had no luck.


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## karaim (Aug 28, 2008)

One more question. Can I use the rock from my father's saltwater aquarium? What do you think that brown stuff on it is?


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## Pasfur (Mar 29, 2008)

Brown stuff could mean anything, but i suspect you are just seeing a brown colored algae or cynobacteria. Yes, you should be able to use the rock, but give it a good scrubbing with a clean toothbrush first to remove the brown algae you are seeing.


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