Using old live rock?

[azreefer]

I've recently transfered my 40 gal tank into a 75 gal and would like to add some more rock. A friend of mine has some rock thats been sitting dry on his back patio for about a year now. The rock came from a tank that had a severe crash. I want to use it in my tank but don't want to risk even a small cycle in my tank. If I scrub this rock and rinse it good will it be ok to stick into my tank or should I cure it somehow?

[D-Lite]

If it came straight out of a tank, and has been sitting outside for a year I don't think a scrub would be sufficient. I think if you really didn't want it to cause any cycle you would probably have to bleach the rocks.

If the rock has any color, thats probably a good indicator that it will cause a cycle. If there's color, then there's gotta be dead algae on it. Plain old calcium carbonate rock should just be white I believe.

Also, this isn't even accounting for the dead worms that are probably inside of the rock that you probably won't be able to remove no matter what you do.

Oye, I think the only way to avoid a cycle in your tank is to cure it like you already said.

[marm64]

I used some old rock in my tank, I got it from a friend that had it in a tank that dried out, and I did not have a problem with it cycling. I did wash and scrub the rock off before I added it to my tank.

[gqjeff]

I am putting in 150 lbs of old LR that has been sitting for about 9 month from my brothers tank.. I also have 150-200 lbs of my own rock that is cured. I am adding them at the same time in my 240. I have to cycle my tank anyways so no biggey for me.

Peace