What do I need to do?

I have about 70 lbs of Fiji rock that has been in a plastic container in my garage for about 4 months now. I bought it from a guy who was tearing down his tank so it was once live rock but is dead now. What do I need to do to this rock before I add it to my tank?

 

i bleached mine overnight and then rinsed about 10 times, last rinse i used ro/di water.

 

So I should still bleach the rock even though it's completely dead?

 

Basically its base rock now. I would just rinse it really good to get any gunk out.

 

Not sure why bleaching this rock would be necessary, unless you knew it was covered in aiptasia or bryopsis or some other pests. If this was the case, I would recommend bleach and then copious rinses.

But if it is just base rock, here's what I would do: Buy a cheap scrub brush (like a toilet brush or some such thing), and scrub off everything you can remove from this rock and rinse copiously with saltwater. Then, if you are setting up a new tank, add it to your tank and throw in a small piece of live rock to allow the base rock to re-colonize with bacteria/other organisms.

 

Yeah, I'm wanting to just rinse it really good with RO/DI. I'm nervous about bleaching it just because there's a chance of getting bleach into the tank.

 

The rock will be going into an established tank. Would this method still be OK?

 

I would put it through the cooking process. Even though the rock is dry, it has absorbed a ton of phosphates from the critters that have died on it and probably for being in the guys tank for a while. You have a strong possibitlity of running into algae issues with it if you don't cook it. Here's what I would do to cook it:
Put the rock in a container in sw with a powerhead (heater not needed)
Do a 100 percent water change on the water twice a week for about 2 months or so.
Then place into the tank.

By doing this, you are allowing the rock to leach all of the phosphates that have accumulated in the rock and dumping them out with the water. You have to change the water often though as the rock will stop leaching the phosphates if the water gets too dirty.
By the time you are done, you will have perfect rock that will be 100 percent algae and phosphate free.

 

In that case, adding this rock to your established tank will likely cause a mini-cycle, which could potentially harm your livestock (although it may not).

To be on the safe side, I'd cycle the rock separately. Brush it and rinse it as I suggested above, and then fill a vat/garbage can/whatever with saltwater. Place the rock in this water with a small amount of liverock, a heater, and a small powerhead for circulation. Leave it there for a few weeks to get rid of any die-off and allow some bacterial colonization. I'd say that after 2-3 weeks of this you'd be fairly safe to add it to your tank.

Just to clarify - none of this may be necessary, but if it were me I'd not want to risk a mini-cycle.