I'm sure some are asking, "What is old dead LR? What is old dead LS"
Dead Live Rock (read about LS further below)
This is Live Rock that has been left out to dry or because of being covered with nuisance organisms, like Aiptasia Anemones, Majano Anemones or Hair Algae, has been treated for a day or more in a bath of freshwater or bleach or some other solution designed to kill the bad stuff.
Some hobbyists will use this dead LR in a startup reef aquarium. Problems can arise with this. The biggest problem is that coral and algae fail to grow and sometimes even die.
Let's look at why this happens. This once live rock has become dead all
the way into the center. Yes, the center of LR is alive too, with
essential bacteria. I treat LR the same as I would a coral or a fish. It is really that valuable as a live colony of organisms. Nitrification and Sulfurization processes occur within the center areas of Live Rock. These processes are a very important part of the filtration needed in our little eco-systems.
When the bacteria in the center areas are killed and then the
rock is placed back into the tank, the chemical compounds, the pollution from that dead stuff, leaches
back out into the tankwater. These polluting compounds are irritating to coral and can even completely stop
coral and algae growth.
The simple answer to this problem is of course not to use old dead LR. If hobbyists realized this about LR, they would treat it with more TLC. They would avoid leaving it out to dry or would use alternative methods of cleaning of the nuisance organisms. But there is a way to avoid the problem.
What I have described above is not always the case. Some dead LR does not seem to create the problems mentioned. Also, if a smaller percentage of dead LR is used along with good LR, the problems are less noticeable. A hobbyist who adds several nice pieces into a mature reef tank already containing a complete array of good healthy LR will notice that the new pieces take a little longer to come to life, but they do eventually come back.
There are two products I know of that can help fix the problem. "Poly Filter" and "Purigen" are specifically designed to remove harmful chemical compounds while leaving useful elements and nutrients in the water. I have heard some hobbyists claiming bad effects with the continued use of Purigen. If I had the problem and had access to Purigen, I would try it for a few weeks and then remove it, hoping it had helped.
To be certain of fixing the problem with no bad effects, I would suggest Poly Filter. I personally used Poly Filter in a 75 gal tank that I set up full of old dead LR. The first 2 months since setup had seen no growth and even the death of coral and a BTA placed in that tank. I placed a pad of Poly Filter in a HOB Filter. Within a few days there was a noticeable difference and within 2 weeks the algae and coral were growing
normally.
To be sure to remove all the compounds from the rock, at two weeks I replaced the used up pad with a new pad and let it run for another 2 weeks.
Dead Live SandCan I use a bucket of sand that came with the tank and sat for a week? It's still wet/damp.
Yes, but the same principles apply as above with LR. That bucket of once Live Sand is now dead and stinky. LS is alive. It
had billions of live critters, from bacteria and protozoans to grammarus
and worms. By putting it all in a bucket and placing the
lid on top, the life was suffocated. Without oxygen, the whole bucket
went anaerobic and killer hydrogen sulfide/rotten egg gas is the result.
I would be very careful with old dead LS.
Depending on the length of time the sand was in the detrimental
conditions, it should be rinsed very clean with freshwater and never
used as the exclusive source of sand in a tank. It will need the same
care as using old dead LR.
If a hobbyist wants to preserve the life in the LS, it should be kept in a bucket for no longer than 4-6 hours or placed for a longer term in tubs with no more than 6" sand depth covered in 3-6" of good tank water above the sand level. A powerhead for circulation will help even more.
Edited by Mark Peterson - June 19 2010 at 9:03am