Rock "Cooking"--a dangerous trend or something worthwhile?

finneganswake · #1 01/28/2006, 01:33 PM

I was hoping to get some expert advice on what I see as the newest unfounded fad on RC--"cooking" your live rock. It's all over the general forum; pretty much any algae issue that is presented is answered by a chorus of "Have you cooked your rocks yet?" Not "What are your husbandry procedures," "Do you use RO/DI," "Do you overfeed," etc. It's always about the rock "cooking." If you aren't familiar with this procedure, it's basically something started by the same people who used to answer all algae issues with "Have you removed your sandbed yet?" instead of asking the probing questions I've previously mentioned. This "go bare bottom" trend was sold as a cure-all that was going to forever remove the chances of a tank having algae problems. When it turned out that the people who were blaming their sandbed for their problems still had algae issues after removing it, the next step was not to question their husbandry but to blame the rocks. They say that "uncooked" rocks leach phosphate (didn't we hear the same thing about sandbeds?) and through their "shedding" constantly dump detritus into the tank. Their solution is to "cook" the rocks by (and this is a somewhat simplified version of the treatment, but it should suffice) removing them from the aquarium, putting them in a dark container for months while swishing them every week or so. At the end of the process, you have what is, in my opinion, dead rock, although the proponents of this treatment claim that somehow only nuisance organisms are killed. One thing that leads me to believe that this process doesn't work is that many people have algae problems after "cooking" their rocks; these people are told that they didn't "cook" them long enough, or that they just need to do it again--it's not uncommon to hear that you need to do this every few months.

I want your opinion on this in the hope that people will be more likely to listen to you than to me. Is this cutting off the leg to save the toe? It seems to me to be a very desperate maneuver and unlikely to offer any longterm results compared to a thorough look at what factors caused the problem to begin with. If this is such a necessity (and it is being promoted as something you have to do to keep algae out of your tank, as eventually the rocks will leach so much phosphate that your tank will crash) how come nobody that I know with a nice, algae-free tank has ever "cooked" their rocks?

Thanks for your help.

Randy Holmes-Farley · #2 01/28/2006, 02:41 PM

While it may be a useful way to remove some nutrients from old rock, I've never done it and don't see a reason to do it in most circumstances. I have rock that is more than 10 years old, and I'd hate to kill off the organisms that are growing on it. Unless you intend to keep the aquarium in a fashion that is very different than before the rock was cooked, it seems to me that it will not take long at all for the nutrients to be deposited again, and you have lost a big variety of organisms that lived on it.

Someone once posted the rhetorical question "why use live rock" if you are going to cook it?" I tend to agree with that.

finneganswake · #3 01/28/2006, 02:49 PM

Thanks, Randy. I posted on a couple of other advanced discussion forums and once they reply, I'm going to post the answers on the general forum. Hopefully, the people having algae problems will listen to the pros.

inwall75 · #4 01/28/2006, 03:08 PM

Quote:

Originally posted by Randy Holmes-Farley
Someone once posted the rhetorical question "why use live rock" if you are going to cook it?" I tend to agree with that.

You can't tell the difference between the rock that I've cooked and the rock that I haven't cooked. I've not lost organisms. I still have plenty of pods, spaghetti worms, feather dusters, vermited snails (well I would mind if the snails were gone). The rock had just as much coralline as before.

I basically only experienced good things from the experience and none of the perceived disadvantages.

Randy Holmes-Farley · #5 01/28/2006, 03:14 PM

What did the cooking accomplish?

inwall75 · #6 01/28/2006, 03:27 PM

The rock bin that I bought my live rock out of was filthy. There was also some algae in it. I didn't want that in my tank so I cured it longer than most people do. (I also cured it on top of a brand new sandbed which I would never do again). I basically did this until the rock stayed clean.

I didn't do it the way that SeanT recommends because I did it at a time when I had never even heard of cooking rock. I used a protein skimmer, powerheads, but no lights. I siphoned the nasty gunk out of the bottom of the tank with a freshwater gravel siphon. Every few days, I took a powerhead to my rocks and caught all of the gunk with a micron filter bag which I then changed out.

I guess technically, you can say that I didn't cook my rock in the current usage of the term but it was similar. I never had algae problems in that tank even though I was a newbie. I did have dinoflagellates but learned from my overfeeding mistakes shortly thereafter.

I have picked up cheap rock that people leaving the hobby are selling and cooked it in a manner that is more similar to the current method.

finneganswake · #7 01/28/2006, 03:40 PM

Inwall, it sounds to me like you cured your rock in the dark. That's a very good idea with new rock (although personally I prefer lights on) and not the same as cooking.

What SeanT is pimping to everyone is the idea that whenever you have an algae problem in an established tank, you should rip all of the rock out of your tank and basically kill it. This is a ludicrous solution to what, in 99% of the cases, boils down to husbandry issues that could easily be addressed in a less destructive way.

Randy Holmes-Farley · #8 01/28/2006, 03:43 PM

Yes, if you are basically starting things over anyway, it seems like a fine way to go. But as a routine way of dealing with algae, it seems excessive to me.

inwall75 · #9 01/28/2006, 03:57 PM

Well, I suppose it's a matter of degrees at how bad the algae is. If you have a small amount of algae here and there, it seems like an awful lot of work and a waste of a lot of salt. However, if your tank looks like this.....

I routinely cook in the more traditional sense rock that I'm buying from someone leaving the hobby unless I know them and I've seen their tank. I have to question, "Why are they leaving the hobby? Did they have massive algae problems?" How many algae spore are hiding in this rock?

I think that if you don't become obsessive over cooking, it's just another weapon in our arsenal against algae and phosphate problems.

finneganswake · #10 01/28/2006, 04:04 PM

But there are lots of people who have come back from algae problems just as bad as this without cooking their rocks. These people have the added bonus of learning what caused the issue in the first place. All cooking the rocks does is kill the algae--it doesn't solve the husbandry issues that caused it in the first place. An analogy is the red slime remover--sure, it gets rid of cyano (temporarily), but what have you learned? You still have the source of the cyano in the tank. I don't see why people can't accept that algae doesn't just magically show up because of "phosphate sinks" and "shedding" and other buzzwords. It shows up because the owner of the tank is doing something wrong.

inwall75 · #11 01/28/2006, 04:20 PM

Quote:

Originally posted by finneganswake
I don't see why people can't accept that algae doesn't just magically show up because of "phosphate sinks" and "shedding" and other buzzwords. It shows up because the owner of the tank is doing something wrong.

I would agree with that usually. However, I did have a friend who bought some LR and had algae problems that were amazing. Her entire bioload in a 220g was one bi-color blenny. The rock was definately problematic when it was brand new. It was GREAT LOOKING rock from Pukani until it got coated with tons of hair algae. You couldn't obtain a phosphate reading in the water column because algae and bacteria got to it too quickly. However, you could stick a syringe into a hole in the LR, suck out water, and test high phosphates from there.

I helped her aquascape and the rock was still damp right out of the box. She cured properly, used RO/DI water, wasn't really even feeding the blenny because it would eat algae yet she definately had issues with her rock.

I would say that not everyone needs to fix their rock by cooking but wanted to point out that there can be problem rock. I would also agree, that when you have a problem, you need to examine your habits to figure out what you did wrong. Unfortunately, occassionally, you didn't do anything wrong.

EDIT: When this picture was taken, the rock was only being lit for about an hour a day. She didn't have her blenny yet so there was no bioload at all other than hitchhiking critters and bacteria.

finneganswake · #12 01/28/2006, 04:54 PM

I absolutely agree with you that there can be problem rock, but you're still talking about curing rock, not cooking it. You said that your friend's rock was problematic when it was brand new--thus you cure the rock. Maybe it takes three months instead of three weeks, maybe you keep the lights off instead of on, but it's still curing. If the problem wasn't solved, the rock wasn't cured correctly--I've seen this happen plenty of times. The first time I cured live rock, I didn't have enough flow. I tested the water and there was no ammonia or nitrites. When I smelled the rock, however, it was obvious that there were "dead" pockets that must not have spilled out into the water due to the lack of flow. So instead of beginning to add stuff to my tank, I added more flow and waited another month for it to cure properly. How many people cure without carbon and then wonder why there are noxious compounds left that cause problems?

Again, my point is that cooking ESTABLISHED live rock is a really bad idea.

Sindjin · #13 01/28/2006, 10:24 PM

99% of the people who dont see the need to cook rock, or say rock cooking kills the life, etc... are people who havent cooked rock.

Quote:

Inwall, it sounds to me like you cured your rock in the dark. That's a very good idea with new rock (although personally I prefer lights on) and not the same as cooking.

Wrong, Finn. Curing rock in the dark is the same as cooking.

Cooking rock kills algae and creates a bacterial driven system to aid in the export of internal detritus from inside the rock.

I have been curing my rock in my tank for 3 months with lights on. I still have rock shedding tons of debris. Now... today I blew out my rock with a TBaster. The only thing accumulating on my BB was a pile of sandy detritus too heavy to remain suspended. I extracted that with the Tbaster and placed it in a cup. I tested that cup sample for PO4. Guess what? 4ppm. My water column tests .05ppm. So yes. 3 month old cured rock can still harbor detritus and yes it is loaded with PO4.

Im sure if Randy took his 10 year old rock out...dunked it and swished it... he would have a bucket full of crud which would also test higher than his water column for PO4.

Now... on to SeanT...

SeanT is a very knowledgable person and as helped MANY people with their Reefs. He ALWAYS askes the pertinent questions and does not perpetuate Rock Cooking as the Primary answer. Why are we seeing rock cooking or Dark curing popping up everywhere? Same reason you see threads on Tunzes, DSB Plenums, Ca Reactors, etc.... because they are all advances in our hobby that work for the better.

BB's and dark curing are not fads. 20 years ago at the LFS I worked at we used to cure all our rock in the dark and every Reef display was a BB. Oh BTW..the owner of that LFS...my mentor that I learned under... was one of the founders of Aquarium Phatrmecuticles. Pretty cool.

Randy Holmes-Farley · #14 01/29/2006, 08:54 AM

Im sure if Randy took his 10 year old rock out...dunked it and swished it... he would have a bucket full of crud which would also test higher than his water column for PO4.

Could be. I'm not sure why I'd want to, however. I don't have an algae problem.

Perhaps my and others reaction to the rock cooking being an aggressive, last ditch effort is based on the problem that people seem to mean different things when they say rock cooking, and one typically does not know what is actually being done.

I can't see how keeping rock in the dark for many weeks will allow coralline algae to survive. Yet some of you say it does not kill organisms on the rock. Is that because you don't cook it that long, don't count coralline as an organism, have some way of keeping coralline alive in the dark, or some other reason?

Sindjin · #15 01/29/2006, 09:30 AM

Coralines will die off or at least receed depending on how long you are "cooking" it. It is a photosynthetic organism like all other algaes. The "life" referred to is pods, tube worms, snails, bristle worms, etc. EVERY person I have talked to that Cooked their rock did not see losses of these organisms ...rather they specifically said they see a lot of those life-forms after returning their rock to their tank.

I agree on the confusion of the tern "cooking". All it is, is "Dark Curing" to kill off algaes and allow the bacteria to break down internal PO4 and shed it. I feel this is an important process simply because of the experimnet I mentioned above. Now... If I were running a DSB, all that PO4 enriched detritus would be settling in the sandbed...sinking deeper and deeper and accumulating over time. If the sandbed is deep enough, where anaerobic conditions exist... their will also be acidic conditions as well. since PO4 will bond to calciferous substrates, the acidic conditions (less than 7.9) will cause the release of PO4 from the calciferous substrate. Am I correct in that?

If so... IMO it is VITAL, especially in a NEW DSB set-up to add rock that is as free from internal detritus as much as possible. That, combined with good husbandry skills will help to ensure a more stable, manageable environment over the long term.

Sindjin · #16 01/29/2006, 09:45 AM

Quote:

Could be. I'm not sure why I'd want to, however. I don't have an algae problem.

Not yet... you may never, either. However ridding the rock of internal detritus will help ensure that you wont. Rock Cooking or Dark Curing is not only a cure for the problem tank but also a preventative measure for long term success.

Randy Holmes-Farley · #17 01/29/2006, 09:59 AM

How long do you think that "reduced detritus in the rock" situation lasts for under normal reef aquarium circumstances?

Sindjin · #18 01/29/2006, 10:05 AM

Quote:

How long do you think that "reduced detritus in the rock" situation lasts for under normal reef aquarium circumstances?

honestly I think its never-ending unfortuanetly.

Randy Holmes-Farley · #19 01/29/2006, 10:08 AM

So the question is, does the cooking do something that has provided a significant benefit that is gone in 3 weeks? 3 months? 3 years?

If 3 years, it sounds a lot more useful than if it only lasts 3 months.

Sindjin · #20 01/29/2006, 10:18 AM

Yes. Cooking rock in a closed, dark environment does a few things. Obviously... killing algaes. But more importantly, in a cooking environment, you are not adding any food for the bacteria. So they are forced to bore deeper in the rock to feed, therefore cleaning out detritus that may not get consumed under normal circumstances in the aquarium where food would be more plentiful, closer to the outside layers of the rock. Then when placed back in the aquaria, with good husbandry and lower nutrient environments, the bacteria will thrive toward the outer layers while the internal areas stay clean and free of built up detritus. Now it is my understanding that when Nutrients are plentiful (poor husbandy, higher bioload) the bacteria will actually store nutrients deeper in the rock to be used later on.

EDIT:

Im my tank for example... its a low nutrient environment with some food sources at the rocks surface. However the bacteria is still boring deeper and feeding...thats why I'm still seeing a lot of shedding...especially in the form of mineral detritus and not so much snail/fish poop.

bertoni · #21 01/29/2006, 01:16 PM

Quote:

Originally posted by Sindjin
Yes. Cooking rock in a closed, dark environment does a few things. Obviously... killing algaes. But more importantly, in a cooking environment, you are not adding any food for the bacteria. So they are forced to bore deeper in the rock to feed, therefore cleaning out detritus that may not get consumed

This part isn't making any sense to me. What do you mean by "boring into the rock"? Also, I don't believe any detritus is just going to sit in the rock. Where there's food, there's organisms eating it.

Sindjin · #22 01/29/2006, 02:26 PM

Quote:

This part isn't making any sense to me. What do you mean by "boring into the rock"? Also, I don't believe any detritus is just going to sit in the rock. Where there's food, there's organisms eating it.

Just like any other living organism, bacteria will go where the food is. If you are feeding Live Rock and there are higher concentrations of food toward the outside of the rock...thats where the majority of the bacteria will live, die and feed. The problem is we cant know how much food is buried/stored deep in the core of our rock so to assure that it gets consumed we cook the rock. Eventually, outer food sources will be eliminated with scrubbing, dunking, swishing, water changes etc. With no outside food source available, what will the bacteria due to survive? Go to where the food is. Stored internally from who knows how many years of build up, etc. If you cure your rock in tank, with light, algaes, snails, hermits, fish, etc... you will be providing a food source for the bacteria. In my tank for example, I have done just that. However I am also focusing on exporting nutrients, blowing off my rock, changing water weekly and feeding my 3 fish once every other day with no excess. It has taken 3 months, but finally I am seeing the ending stages where the only detritus really being shed is the mineral/sand from inside the rock, which is finally being exported by the bacteria.

bertoni · #23 01/29/2006, 02:56 PM

I don't see any reason to believe your scenario. I think it's possible that some live rock has a lot of organisms in it, that dark curing would kill. I can also believe that some rock might have a heavier load of phosphate that could cause problems. I don't see any reason to believe that's common.

As far as bacteria going into the rock and snails, fish, etc, providing a food source, and assuming from there that the rock can't be made usable is simply not credible to me. People do it all the time.

Sindjin · #24 01/29/2006, 03:07 PM

Quote:

I don't see any reason to believe your scenario. I think it's possible that some live rock has a lot of organisms in it, that dark curing would kill.

What organisms living in rock would Dark Curing kill? These are bacterial organisms, etc that already live in complete darkness. They would actually thrive in this environment, IMO.

Quote:

I can also believe that some rock might have a heavier load of phosphate that could cause problems. I don't see any reason to believe that's common.

Oh no? Just look at my rock. It was Fresh from Fiji. Smelled SO clean it was amazing. 3.5 months later I'm still blowing out detritus from inside the rock and I extracted the sand accumulated on the bottom of my BB (This was yesterday). I test that sample for PO4 and voila... 4ppm. Meanwhile my water column tests .05. I think it is VERY common that rock is loaded with PO4...organic or inorganic. We as hobbyists just havent tested for it specifically... rather we test our water column and think everythings ok. Whether it would ultimately cause a huge problem for me? Who knows...but the PO4 is present nonetheless.

Quote:

As far as bacteria going into the rock and snails, fish, etc, providing a food source, and assuming from there that the rock can't be made usable is simply not credible to me. People do it all the time.

I never said the rock cant be usable. And just because people do it all the time doesn't make it the best method, either. Just ask the Lemmings.

gillies · #25 01/29/2006, 03:10 PM

First, I'm glad Randy is giving this process some consideration, as he always provides straight answers and simple solutions to various issues. Second, I must say that Sean T has presented his case for cooking rocks as an option to rid a tank of algae issues and has never claimed it to be the only solution.

I have read and re-read the threads on this topic. It seems to me that cooking rock is a drastic measure. I don't relish the idea of tearing down my system and waiting eight weeks to put it back together. But for those struggling with ongoing algae issues that have not declined after using traditional methods, perhaps cooking can offer them a fresh start.

I have not tried this method, yet. So I cannot speak to its effectiveness, but it does have its appeal for me. I struggle with valonia and "red turf" and have read that are both low-nutrient algaes. My water parameters are fine and my flow is good. Hell, my tank often gets more attention than my family, so I don't feel husbandry is the problem.

My questions for Randy would be: as far as the die off of organisms, won't corralin algae regrow over time? Wouldn't putting in a few pieces of fresh live rubble re-seed the system with additional life forms? Will this method offer me a chance to "try again" with the battle against "low nutrient" algae?