Cooking old live rock

[Aquatic Noggin]

I have several pounds of "live" rock that has been in dry storage for 18 months. When it was removed from my tank, it was covered in hair algae and I hosed and scrubbed it with tap water before I stored it. I want use this rock again as base rock. Will cooking this in fresh rodi water for several months with frequent water changes clean it up? I don't want to waste salt if it's not needed.

 

[staticxtreme]

I cooked up some rock and never had any problems, I don't see why you would either.

 

[Aquatic Noggin]

So, did you use fresh water and it worked?

 

[andycook]

Cook it in SW so you can start establishing bacteria.

 

[GSchiemer]

Boy, this "cooking live rock" thing has gotten so misunderstood and out of control.

At this point, there's no reason to put the rock through an extended cycle (AKA "cooking") since it's dried and dead. There's nothing left to salvage. Instead, scrub off any visible material and soak the rock in a light solution of bleach for a few days. Follow this by a soaking in freshwater with dechlorinator for a few days. Rinse with freshwater and the rock will be ready to be placed in the aquarium.

Greg

 

[Aquatic Noggin]

<a href=showthread.php?s=&postid=6960151#post6960151 target=_blank>Originally posted</a> by GSchiemer
Boy, this "cooking live rock" thing has gotten so misunderstood and out of control.

At this point, there's no reason to put the rock through an extended cycle (AKA "cooking") since it's dried and dead. There's nothing left to salvage. Instead, scrub off any visible material and soak the rock in a light solution of bleach for a few days. Follow this by a soaking in freshwater with dechlorinator for a few days. Rinse with freshwater and the rock will be ready to be placed in the aquarium.

Greg

This may work for what I'm trying to do. My only concern would be eliminating phosphates that may have accumualted inside the rock. From what I understand cooking over a long period of time will force phosphates and other junk out of the rocks. Is this true?

 

[andycook]

GSchiemer, what you describe will take care of the external aesthetics of the rock. No one is suggesting that there is anything left to salvage. Because the rocks are porous cleaning the outside doesn't address what accumulated in the rock and dried and died there.

 

[Alaskan Reefer]

I have rock in my FOWLR tank that spent 2 years in my rock garden. Outdoors. With lots of weird weeds growing out of it when I brought it back in. Bleached it heavily (about 50/50 solution), rinsed thorougly, and let it sit in the air to dry for a couple of days to dechlorinate. The rock was electric white when I put it in, seeded with one small piece of coraline encrusted rock, and the whole tank was purple six months later. Definitely no phosphate coming out of that rock (coraline wouldn't have taken off like that if so), even though it took on fertilizer overspray and who knows what while sitting in the yard.

So, long story short, IME strong bleach will clean just about anything, including porous rock.

 

[andycook]

How does bleach clean porous rock?

 

[GSchiemer]

<a href=showthread.php?s=&postid=6960892#post6960892 target=_blank>Originally posted</a> by andycook
GSchiemer, what you describe will take care of the external aesthetics of the rock. No one is suggesting that there is anything left to salvage. Because the rocks are porous cleaning the outside doesn't address what accumulated in the rock and dried and died there.

It's clear that you don't understand this so-called "cooking process" and what it's meant to accomplish. The supposed "cleansing" of the rock during the "cooking" process is the result of biological and bacterialogical activity within the rock. Since this rock has been left dead and dried for 18 months, there is NO biological activity and absolutely NO point in "cooking" it in fresh or saltwater. OTOH, soaking it in bleach will neutralize all organic material BOTH IN AND ON the porous rock, which is what we're trying to accomplish. Any INERT remaining surface material and detritus can be simply brushed off and hosed away after the bleaching and soaking process has been completed.

Greg

 

[Alaskan Reefer]

andy -- I assume it dissolves proteins, just like it does in the laundry? Aside from the places where the bleach molecule is too large to penetrate, of course.

Similarly, wouldn't soaking the rock in some kind of weak acid like say Coca Cola do the same thing?

 

[Aquatic Noggin]

<a href=showthread.php?s=&postid=6961999#post6961999 target=_blank>Originally posted</a> by GSchiemer
It's clear that you don't understand this so-called "cooking process" and what it's meant to accomplish. The supposed "cleansing" of the rock during the "cooking" process is the result of biological and bacterialogical activity within the rock. Since this rock has been left dead and dried for 18 months, there is NO biological activity and absolutely NO point in "cooking" it in fresh or saltwater. OTOH, soaking it in bleach will neutralize all organic material BOTH IN AND ON the porous rock, which is what we're trying to accomplish. Any INERT remaining surface material and detritus can be simply brushed off and hosed away after the bleaching and soaking process has been completed.

Greg

I understand what you're saying here Greg but what about the inorganic compounds like PO4 that is deep within the rock?

 

[Alaskan Reefer]

If you're not sure, you could always just start bacterially "cooking" them and see if they shed after a couple of weeks. If not, additional cooking probably isn't going to do anything more. You'd need a fresh piece of cured LR to start the process of course, to have some sort of seed bacteria.

The rock I threw in the yard was covered with hair algae, so assumedly packed with PO4. Sat there and grew weeds for a couple of years. After bleaching and reintroduction to a tank, no shedding, no hair algae -- just circumstantial but I assume that meant it didn't have any more stored PO4.

If there is PO4 deep within the rock and you keep your water clean, it will all come out anyway as detritus, right? That's the principal of bacterial cooking, I believe. So the only risk with bleaching and putting the rock in instead of cooking it would be that you might have to do a few more water changes to combat leached PO4 or the additional detritus created from whatever quantity existed in the rock that the bleach couldn't clean off.

 

[Alaskan Reefer]

I bacterially "cooked" my rocks for three weeks while transferring from my 75 to my current 125, assuming I'd see some magical results with detritus pouring out -- especially since that tank had a hair algae problem at one point. Well, none did, no matter how hard I swished or blasted them with powerheads. My only assumption is that whatever was stored in the rocks eventually leached out and was consumed by the macroalgae in my refugium (which was added to combat the hair algae), and that the rocks were thus already "cooked" in the old tank.

The concept is decent if you start with live rock that comes from a poorly maintained system. Otherwise, I don't know why you wouldn't just bleach it.

 

[andycook]

GSchiemer, simply letting your rock dry out doesn't give you clean rock inside and out. The material being worked on by the biological and bacteriological activity still remains when the rock dried.

Alaskan Reefer, are you proposing the Syrrup method?

Aquatic Noggin, I'm suggesting that this would also be a good opportunity to start re-establishing bacteria so you should use SW.

 

[Aquatic Noggin]

I have plenty of live rock that is in my tank now that will eventually seed the base rock when I setup my new tank. I just want to use the old stuff for base rock and don't want to go through the rather tedious process of cooking it if it's not necessary. Right now I'm leaning towards bleaching.

 

[andycook]

Let me know how it works for you.

 

[Aquatic Noggin]

I will- it might be awhile before I get my new tank up and running though. Thanks for your help.