Will there be a cycle???

[mantis1437]

Hi everyone! I have been lurking around for years and found lots of useful info on here. Now I need an answer that I can't seem to find on here. I just upgraded to a 180 and I need more live rocks to it. I found a great deal on some dried live rocks. So will there be a cycle if I add dry live rocks to an establish system?

please let me know
thanks in advance!
michael

 

[Toddrtrex]

Maybe -- how's that for an answer.

The issue is that the rocks were once "live", and have a chance of having a decent amount of organics on/in them. I would rinse the heck out of them, and might even let them soak in some salt water for a week or two -- you could just use your water change water. During that time I would test the water for nitrates and phosphates, to see if the rocks are leaching out anything.

 

[Prairie Reef]

I have a very small sample size, but I started a 75 with 1/2 live and 1/2 previously live and didn't have a cycle. Just my experience which is pretty limited.

 

[davocean]

I think it also depends on how much dry rock you are adding, and how much established LR is already in there.
I have added a couple small rocks to my system and the established rock I had helped to seed the dry w/out issues, but that was in small amounts.
Safest bet would be follow Todds advice, and if it is any decent amount at all that is what I would do.

 

[mantis1437]

alright thanks guys. So the answer is yes most likely. I am going to cycle it with water changes from my tank for a few weeks before it goes in.

Thanks alot
michael