Old Rock

[Anghrndz]

I have rock from my tank that I took down in February. It has been dry since then, can I use it in my new tank? 

[seabass]

 to Nano-Reef.com.

 

You'll have to cure it.  Was the rock cleaned before you dried it?

[Anghrndz]

No I had an unexpected fire due to a leak and it was the last thing on my mind. How do I cure it? What will happen if I use it as is?

[Kyle99]

So from my experience. Although im not very experienced, what has happened is that anything that was living in/on those rocks is now dead. Well almost everything. Dead things mean high phospates/nitrates ect. Cycling the rock alows the rock to bleed all the nasties off in a controlled space before putting them in a tank. 

 

To cycle the rock put them in a container with rodi and salt. Then add a powerhead or something to cause flow. Test for ammonia, nitrites, nitrates, and phosphates. Changne the water out a few times (over a pirod of time just like your tank) till you dont see a rise in these levels. 

[seabass]

Curing it is basically just cycling it.

 

A separate container is handy; but if your tank doesn't contain livestock (or true live rock), you can certainly cure it in your tank.  You'll just have to change out a significant portion of water after you're done.  As Kyle99 stated, the dead organics left on the rock will be broken down, releasing nutrients and dissolved organics, while producing ammonia.

 

Other bacteria will break the ammonia down into nitrite.  And still other bacteria will process the nitrite into nitrate.  Most of our tanks don't support enough denitrifying bacteria to complete the nitrogen cycle.  However, we typically export the excess nitrate through water changes, or uptake from macroalgae (or even some form of carbon dosing).

 

If there is any organic material currently on the rock, you can brush it off with a vegetable brush and/or a toothbrush.  I've even used a pressure washer to clean off dry rock before.  There is little advantage to just letting it all break down in your tank.