Can I use 6 mth old DRY Rock (Formely Live)

[mirski57]

I have in my possesion from a friend 175 lbs of previously used Fiji Live Rock. However, it's been sitting in the garage in styrofoam containiners for 6 months(no moisture). Can I still use this ? I know that it is not "LIVE" and it wouldn't contain all the critters fresh live rock would have. But wouldn't it eventually got populated after 5-6 months ?
How would I go about curing Rock that doesn't have critters. How long would this take ? Do I need a heater during the curing process, or is room temperature okay(65F) ? I probably wouldn't need to do water changes either right ? (maybe once every 3-4 weeks until cured).
Could this rock still be used for effective nitrification/denitification ? Currently, I use a Wet/Dry with bio-ball media.
I've been wanting to fill up my 90gal (8 months old) with Live rock, but Live Rock in a 90gal would cost in excess of $1,000.

Please advise,
Mirski57

[DKKA]

You can certainly add this rock to your tank and it will eventually become liverock, provided you add a couple pieces of liverock to seed it. This dead rock should not need to be cycled. You'll want to remove any dead sponges, etc. that you see (maybe give it a good once over with an toothbrush followed by a good rinse.) But that should be all you need. If you are worried about an ammonia spike you could add just a few pieces at a time to your tank.
Just keep your calc/alc up and add a few pieces of LR and you're all set.
If this is to be a reef tank then you could certainly remove the wet/dry in a few months. If it's a FOWLR then keeping the biomedia will depend on stocking levels. You may be able to remove it if your tank isn't too crowded.
HTH, Dan

[OrionN]

DKKA,
I think you are wrong in saying that these rock does not need to be cycle. I think they contain lots of dead worm and organic materials that are dried. These will decompose in sea water and will cause spike in nutrients and amonia. They should be cure before adding to a reef tank. You can cure them in a small container because ther will not be any need to save the living organism in these dried dead rock.

[sculpin]

Minh is correct. I am currently cycling deadrock for use in fragging. It showed quite an impressive ammonia spike the first week or two. You would be wise to cure yours for one to one and a half months with a heater and a skimmer. I also add a hang on powerfilter with some live biomedia, since I don't care if my curing water has elevated nitrates and this helps drop ammonia and nitrite much faster.

When cured, this rock is biologically equivalent to regular LR and will be colonized by the typical LR organisms in time.

[DKKA]

Minh, I think you probably overestimate the amount of biomass left on the rock...while I probably underestimate. Either way, I believe his trickle filter would be able to handle whatever ammonia was produced from the rocks after they were scrubbed and rinsed.
Certainly if you put a large amount of rock in a small, sterile tub and circulate a small volume of freshly mixed saltwater, you will see some ammonia. But in a well established 90 gal tank with all it's bacteria and micro algae, PLUS a trickle filter....
But, I would never try to talk someone out of taking the cautious approach. And curing would certainly be safer than adding the rock all at once. He would still be okay adding the pieces a couple at a time with a few weeks in between additions. I have done this many times on tanks with less filtering capacity than he has.
Dan

[OrionN]

DKKA,
I would think that dried live rock would give a higher ammonia spike then usual live rock. This is assumed that the original live in the rock is the same. In dried live rock, everything would be dead. When the rock dried out, the water elaborated but the organic form dead organism would still be there in the rock(like the dried food that we eat) With placing in the tank, all of these organic would result in a huge ammonia spike.
No spike is worse then dried out Live rock and live sand, IMO. I don't know if his filtering system can handle the spike or not, but I would expect the spike to be higher than the same weight of uncured MO live rock. 175 lbs is lots of rock I would doubt that the 90 g tank would be able to handle them. I would cure them in a separate container before add them to his 90 g tank.
I would not need to change water or keep it warm. There is no live in these rock that need to be save. A very harsh cure would be just fine. When the ammonia reach 0, I would rinse and scrub these rock well and them place them into the tank.

[Edited by Minh Nguyen on 03-28-2001 at 11:36 PM]

[rshimek]

Thanks Minh,

I think Minh's advice is well taken. Dried live rock has a lot of ex-life in the interstices and internal pores. In addition, the rock is riddled with endolithic algae (alga living within the rock material) this has died (it normally makes it through the standard curing practice just fine) and will continue to rot in the tank for several weeks or months.

Personally, I would not use it at all, and would simply get some good decorative rock from a local landscaper or in my case from the local mountains.

:D