Adding "dead" rock to a cycling tank

Benny Gyger · Apr 1, 2017

Hi. So I received about 40 lbs of once LR. It's been out of the water for about 2 weeks. It looks quite white. My 180 gal tank is in the 2nd week of cycling. Do I have to "cure" the dead rock or can I clean the rock and add it? I also have purchased LR in my tank that's cycling.
Thank you

4FordFamily · Apr 1, 2017

It's probably best to cure it as any organisms on the rock will likely break down quickly and foul the water.

I'm not really sure how you would do that, I just Willy nilly add rock which is against what I'm advising, however.

Murica · Apr 1, 2017

Pretty positive you can just clean it off and throw it in. That's what I did with mine and I had no problems. Only difference is my dead rock had been in the sun for about a month after getting pressure washed, yours may still have life on it.

cracker · Apr 1, 2017

Does it have any obvious dried up algae or such? If so " maybe'" scrape/remove as best You can and add it. It may prolong the cycle of course.

40B Knasty · Apr 1, 2017

Scrape off everything you can see like sponges especially. Give the surface a good scrub down. That way the only ammonia is what is on the inside of the rock. There is a term called "cooking' the rock. 2 weeks in a bucket with no lights, pump, and protein skimmer if you can. This will help.
I literally cooked 20lbs of live rock in a deep fryer with water for an hour. Let it dry for 3 days. Then baked it on 450F. I do not recommend this unless you 100% understand that is dangerous and need to not breathe around it in the boiling water or especially when you lift the lid, eyes closed, wear safety goggles, gloves, do not breathe when opening the oven, eyes closed, and no one or pet is in the house while baking it. Windows and doors open. Stay outside. Fan blowing outside. This kills all bacteria and helps a lot with cleaning it.

Benny Gyger · Apr 2, 2017

I'm debating just scrubbing it and letting it soak for a day or two. Then throwing it in my tank. I'm in no hurry to slow my cycle or even restart it. Cause my fish are in QT for about 8 weeks for a case of ich

40B Knasty · Apr 2, 2017

Perfect then! If you have any ammonia it should take about 6-8 weeks to flush a lot of it out. Put your power heads facing the rocks to get as much movement into the porosity of the rocks. Maybe even switch angles every week.

Benny Gyger · Apr 2, 2017

Will this rock eventually turn back into live rock?
And should I run some carbon to remove anything that leeches into the tank?

cracker · Apr 2, 2017

It will turn into Live Rock.

Lesley · Apr 2, 2017

After 2 weeks there won't be much living
We are scapeing with new
2nd hand rock
We soaked in 50/50 bleach rodi for 2 days
Removed - power washed all dead organics
Left to totally dry then soaked again 3 weeks 100% wc ever 3 days while leaching phosphate
When phos went from 32 to
0.11 we dried again
Using now to scape

Benny Gyger · Apr 2, 2017

I actually found a guy selling 50lbs for $50 of good Live rock. Would this be better to add to my rockscaep rather than use the dead stuff?

Lesley · Apr 2, 2017

Benny Gyger said:
I actually found a guy selling 50lbs for $50 of good Live rock. Would this be better to add to my rockscaep rather than use the dead stuff?

Live rock will have more die off in the tank and may cause a mini cycle

Benny Gyger · Apr 2, 2017

I went with a mix of the live rock and the dead rock. I see creatures. And a tiny tiny starfish on the front of the glass

PatW · Apr 2, 2017

Many people avoid live rock. It can easily come with problem organisms. It can also be loaded with excess nutrients.

Now if you get dry rock from a reputable source, it might be fine to add it right away. It is safer to cure dry rock in salt water. That will allow nutrients that might be in the rock to leach out. It will also allow dried organic matter on the rock a chance to decay.

Benny Gyger · Apr 2, 2017

There are some little starfish roaming and a few Kenya tree's and aiptadia's.

1987 · Apr 2, 2017

Yeah...The more I see tanks started from scratch with dry rock the more I think if I ever start a new system that is the way to go. I've been incredibly lucky, but I don't want stuff like that

Benny Gyger · Apr 2, 2017

True. And the LFS's sure are proud of Live rock. $5 a lb! Wow! I'm all about buying used. I just shot some aiptasia with aiptasia X. That stuff works miracles!