Cooking LR Question

Phanman · #1 12-17-2007, 05:31 PM

Ok... so in anticipation of my new 125 gallon tank which will be setup in Febish. I bought 45lbs of LR to cook for a few months in a plastic garbage can. I first bought the rock, and everything looked normal. Placed the rock in a rubber tub at first with salt water, a powerhead, and heater. I let it sit for 2 weeks (man did the water stink like crud), and mixed new salt water in a garbage can with a heater and powerhead. I decided to scrub down the rock before making the transfer to the garbage bin, but noticed that some of the rock had turned black on one side???

Is this normal? some of it (black stuff) seemed to scrub off, but most of it is on the rock still. What is this stuff? Its not slimy or stringy or anything. Comes off like soot...am i destroying my new LR or something?

thx,
John

fencer · #2 12-17-2007, 05:41 PM

Some people dip rock in freshwater to nuke any flatworms hanging around proir to putting it in the salt tanks.

Black Phantom · #3 12-17-2007, 05:54 PM

The two week smell was your rock cycling and a bunch of die off.
Because you don't have any lights on the rock you will probably get a lot more die off. Are you just planning to use this as base rock? Why the long duration in the garbage can?
The black stuff is probably some macro or other type of algae dying.

Phanman · #4 12-17-2007, 07:39 PM

Thx Black Phantom, i just wasnt sure if i should be worried about the black portions of the rock or not. No this rock is going to be used as display rock. I had the time and wanted the rock to be as "clean" as possible when I setup the new tank. I know its beneficial to have the worms in the rock, but i really dont like the look of them. Ill just increase me clean up crew when im ready.

The reason im gonna keep the rock in the garbage can is i hear you need to do this for at least 3months to properly "cook" the rock. Im gonna do 30% water changes every 3 weeks or so to help clear out the crud.

untamed · #5 12-17-2007, 08:39 PM

There would be pretty differing opinions on whether or not you have "destroyed" the live rock or not. It sounds like the process is going to way that you have planned and I wouldn't worry about the black portions.

It seems to me that what you want from live rock is to function as a bacterial filter only.

If the rocks aren't too large, why don't you just boil them? That would do it.

Phanman · #6 12-17-2007, 09:08 PM

Hey untamed,

Yea all i want the rock to do is be a bacterial filter, i dont want sponges on them or any critters living in the rock. some of the LR are quite large, so its a little difficult to submerge the whole rock and boil it. But i have the time right now to "cook" the rock, because im waiting for the new place to be built then im going full steam on my new tank. Hope its half as nice as yours, lol.

fkshiu · #7 12-17-2007, 10:29 PM

I wouldn't worry about the black patches at all. You're only going to lose the photosynthetics initially. It's only after several months with regular water changes that any of the filter/detritus feeders will start to go as you begin to starve them out (depending on how badly the rock was loaded up with crap to begin with). What you'll have left in the end is a spic and span bacterial filter requiring no cycling time.

Myka · #8 12-18-2007, 04:27 AM

The black patches sound like dead sponges to me...totally normal.

General comment...you should keep an eye on Ammonia and Nitrite levels when cooking or curing rock, Ammonia over 2 mg/l can kill off many beneficial critters on the rock.

Zylumn · #9 12-18-2007, 05:26 AM

phanman. I purchased close to 100 #'s of live rock 10 months ago and it was full of hair algae. I put it in a 50 gal tub (barely fit) with a heater and small flow pump, no light. I have changed the water about 6 times and that rock is full of life(pods,crabs,snails, worms, etc), except hair algae. People sometimes completely cook LR to rid it of all life so when they add the LR to their systems they are not adding any of the unknowns, seeding it with a trusted live piece.
Good Luck
Pics please.
Kevin

scumchug · #10 12-18-2007, 07:26 AM

The stink and the black stuff are both normal. Do not boil your rock. Boiling rock completely kills all living organisms. All you will have is a bunch of worthless dead rock.

Your on the right track except I would change the water more frequently. I do a 100% water change weekly for the first two months. The way I cook rock is like this. I remove the rock from the garbage can. Place it in a "wash" tub. I scrub the rock with a plastic brush until everything that can be scrubbed of is gone. I then rinse it in another tub with clean water. (change this water as often, or as soon as it becomes dirty. Then place it back in the garbage can and add clean water.

I do this weekly for at least the first 2 months. keep an eye on the phosphate levels. as soon as they drop I will start pushing the water changes to two weeks until phosphates are undetectable. If you feel lazy, don't worry about scrubbing the rock, but at least change the water.

In the end you will have fresh live rock. Free of any unwanted pests, but full of life and the biological filtration capacity of the rock will be increased due to ridding it of all the nitrates/phosphates it has sucked up over the years.