BBQ

[Miniwhinny]

I have a question about going BB. If you need to cook your rocks and want to strip them of as much unwanted stuff as possible then why use live rocks at all? Wouldn't clean base rocks serve the same purpose? Just wondering what would be left on the LR that would justify the extra cost over BR. Thanks for any input.

[andy]

I don't understand why you'd want to cook your rock and strip it of life for a barebottom tank.

[Miniwhinny]

Well I'm not sure either (relative newb here) which is why I was asking about BR. TRT has a BB forum and it seems to "correct" way to go is to cook the rocks first (not literally cook )

[Nyles]

I will take a stab. First live rock should be clean and free of pests, it should also be free of detritus (waste buildup), and hand in hand phosphates. You want good clean rock, no algae or other intrusive stuff. Cooking helps remove these problems.

 

What you want (in real live rock) is micro organisms and bacteria that help process the water in the tank to purify it. Just as a chemical bacteria can do for your tank. Much in the same way a nitrate reactor works, you house these bacteria deep in the rock at a lower ph (due to lack of flow in the rock) and helps to keep water levels in check.

 

If you where to add dry rock you would need to seed it with live rock or live sand (or something like that) to get the rock going with good bacteria.

 

If you cook the rock per instructions (heat and water flow and change water regularly) you should have a great head start in the hobby.

[Miniwhinny]

Thanks Nyles, you really explained that in a way I can understand.

[andy]

Ahhh, I see. I'm clearly not destined to be a barebottom guy (you should all be very thankful of that (whistle)). To me, liverock hitchhikers are the best part of the hobby.

[Miniwhinny]

Oh I agree, I love looking for new things that seem to emerge from nowhere. I have to say though that my rock is constantly shedding detritus and I wonder where it keeps coming from, how on earth can rocks POOP !!!!!. It's okay at the moment as everything I have are dirty water lovers but I sure get big bug eyes looking at some of the SPS people show off around here (drooler)(drooler)

[dsoz]

The stuff that comes off the rock is actually mostly bacteria. As the bacteria grow and reproduce, sometimes they crowd out each other, and some have to "move out." The ones that move out clump together and we see it as detritus (aka rock poop ).

 

Like Nyles said, the big value in "cooking" rock is that it removes most of the nutrients out of the rock, but the bacteria are still in there. They become the predominant life form. (rather than algae and other hitch-hikers)

 

Think about the rock as a sponge instead of a counter-top. In a sponge, there are a lot of holes that things can live in, even in the deeper levels. If algae lives in these deep holes, it makes the rock look green or brown. Coral skeleton should look white.

 

Since the bacteria get a clean house to live in, they do not compete with algae and such, so they can fill the house with their kind. When an algae comes along and tries to move in, there is not enough room most of the time.

 

There is also some space on the surface of the rock, which is where the coraline algae can grow.

 

HTH

dsoz

[Nyles]

Also note that these "Hitchhikers" are usually not bad, but that they should be observed and watched (if you can and have time) as alot of them can be beneficial. However there are some that like to eat Zoanthids and again some that like to eat fish, and others that like to eat corals and again others that like to eat all of it, so be wary, cooking rock is more for those that have rock that leech unwanted nutrients, inspecting rock is almost worthless as bad things hide not stand out on the outer area of the rock, any new rock should be observed (if it was live rock from ocean) Just be wary, pests are a pain, but cooking rock is time consuming and should be done by everyone if your disciplined and want to show off your good husbandry, patience usually gets the best of us though but also patience is rewarded. I will note too that so far what I have discussed is good info for both bare bottom and sanded bottom tanks. I am in the process of going bare bottom now, but the principals discussed are the same for rock, the difference to me is bare bottom is more sensitive to fluctuations than sanded, but sanded can build up waste if not maintained well. I am talking very vague here.

[uhuru]

I thought I had cooked my rock, but I didn't follow the directions exactly. Make sure you follow the directions explained at TRT.com BB forum. The swooshing and regular w/c's are important. I was lazy about that until the last few weeks. It wasn't enough. My next tank will consist of all dead, dry rock and I will cure it then seed it myself using zeobak and a carbon source.

[Nyles]

Or just keep it simple and seed with one piece of real live rock while it cooks.

[Miniwhinny]

The stuff that comes off the rock is actually mostly bacteria. As the bacteria grow and reproduce, sometimes they crowd out each other, and some have to "move out." The ones that move out clump together and we see it as detritus (aka rock poop ).

 

Like Nyles said, the big value in "cooking" rock is that it removes most of the nutrients out of the rock, but the bacteria are still in there. They become the predominant life form. (rather than algae and other hitch-hikers)

 

Think about the rock as a sponge instead of a counter-top. In a sponge, there are a lot of holes that things can live in, even in the deeper levels. If algae lives in these deep holes, it makes the rock look green or brown. Coral skeleton should look white.

 

Since the bacteria get a clean house to live in, they do not compete with algae and such, so they can fill the house with their kind. When an algae comes along and tries to move in, there is not enough room most of the time.

 

There is also some space on the surface of the rock, which is where the coraline algae can grow.

 

HTH

dsoz

 

What an awesome explanation. I think you made the lights come on (that takes a lot these days lol) it all makes perfect sense to me now. I had no idea that rock poop is dead bacteria.

 

Edited to add - I bet you are a great Chemistry teacher.

[Miniwhinny]

Or just keep it simple and seed with one piece of real live rock while it cooks.

 

I think this is what I'll do.

 

I have about 60lbs of really nice BR sitting around (that once upon a time was premium Marshall Island) If I use one piece of LR to seed the BR I won't have to cook just cycle and if I'm careful about the LR I shouldn't be introducing anything harmful. Maybe I'll pre-cook my "seed piece".

 

Thanks so much

[Sol]

Actually, cooking base rock (while seeding it at the same time) is a good idea as well. The base rock--especially ocean-harvested, rather than land-mined--has the same phosphate buildup deep within its pores, and once you introduce bacteria from some live rock, the same "purging" effect occurs.

 

Basically, be it live or base rock, what you're doing is getting bacteria to eat all the phosphates, and as they eat it the phosphate is bound into the bacteria's little bodies. Once the phosphate's gone (or the bacteria population is so high there's not enough phosphate to go around), the bacteria starve to death, and drop out to the surface of the rock. Then, through dunking, swishing, and water changes, you harvest/remove all of these bacterial corpses, and, in turn, all of the phosphates bound within their body. You keep doing this until the bacteria are at equilibrium, i.e., the bacteria population is not growing or shrinking, and it's no longer feeding on phosphates in the rock; instead, it's feeding on corpses of other bacteria.

 

As you can see, there's nothing about this process specific to live rock. Base rock has the same phosphate buildup, and should get the same treatment.

 

On a side note, it's really cool to watch this process from a more scientific perspective. A biology major friend of mine in college has taken to monitoring all the processes in my reef, and watching rock cooking (through a microscope to watch all the bacteria, and monitor population density etc) was one of the most interesting things yet.

 

-Sol

[andy]

Sol, are you sure about the bacterial consumption of phosphorus? Nitrogen, certainly... but phosphorus? From everything I've seen and read, significant phosphorus export is accomplished via algae harvesting or chemical means (GFO, aluminum, etc).

[Miniwhinny]

Sol,

 

another wonderful explanation ! I had no idea that the dry BR would contain phosphates in the way you described...I'll make sure I cook it too.

 

I'm so glad I'm on this site. I've learned more in this thread than months reading information elsewhere.

 

How do you know when your rock cooking is finished?

[Sol]

When the crap stops coming off. Once or twice a week, you should be dunking and swishing in a 5 gallon bucket, and doing a 100% water change. When you start, the dunk water will be horrendous when you're done, like skimmate almost. When nothing comes off in the dunking, you're done. Usually ~2 months IME

 

-Sol

[Sol]

Andy,

 

Yes, I'm fairly sure. The diifference, is that we're talking about different kinds of phosphates here. Mostly, when we talk about phosphate in a reef tank, we're talking about inorganic phosphate (literally aqueous PO4). And this can only be harvested in the ways you describe.

 

In the rock, on the other hand, we're talking about organic phosphate, phosphate bound in large organic molecules. This is consumable by bacteria.

 

That's my understanding anyway. I'm a physics major, not a chem or bio major Talk to me about fluid dynamics, and THAT I can be sure about.

 

-Sol

[H20cooled]

I started my new setup with 90% base rock, the thing is no matter what you do with the rock you will still end up with algae and other stuff just because you can almost never get your tank to that low of nutrients to stop it. So, I see no point to wasting a bunch of time killing all of the algae off the rocks and then putting it back in your tank.

 

A better way to do this is to figure out what is causing the algae in the first place and work towards eliminating or controlling it and then it will go away. I've done that with every setup I have had and once i was able to figure out what was creating it I was able to stop it dead.

 

Rich

[andy]

I see the point about the organic vs inorganic phosphates, Sol -- thanks. Given the natural breakdown of organic to inorganic phosphates, cooking the rock in a refugium loaded with chaeto and GFO might be a more effective, faster approach?

[dsoz]

Sol' date=' are you sure about the bacterial consumption of phosphorus? Nitrogen, certainly... but phosphorus? From everything I've seen and read, significant phosphorus export is accomplished via algae harvesting or chemical means (GFO, aluminum, etc).[/quote']

 

Phosphates are needed by ALL life. It is a major component of DNA (nucleotides are made of sugar-phosphate-base). It is also used for ATP.

 

Since ALL life uses phosphates, the dead bacteria that slough off contain phosphates. They must have got it from somewhere... They can absorb phosphates from the water and the rock.

 

You are correct in the SIGNIFICANT EXPORT is accomplished by macroalgae harvesting, but bacteria can absorb phosphates as well. The big difference is that it is not usually EXPORTED from our systems unless you vacuum up every piece of detritus every minute. Once the bacteria die and start to break down they release the phosphate back into the water column.

 

Andy- maybe not faster because there is an equilibrium condition with the concentration of phosphate in the rock and in the water column. Also, if the rock is in the light, then the algae in the rock will compete with the chaeto. maybe have a dark tank with the rocks in it, and a lighted 'fuge that is plumbed to it (like a dark tank and a lighted sump) may work... I see a research project coming on... Anyone want to donate lots of LR that I can experiment with "cooking"???? I get to keep the rock when I am done.

 

dsoz

[andy]

dsoz - agreed. Though I believe that once organic phosphates break down into inorganics (and are subsequently bound into live rock, substrates, etc), they are no longer usable by bacteria and must be exported via algal or chemical means.

[uhuru]

I started my new setup with 90% base rock, the thing is no matter what you do with the rock you will still end up with algae and other stuff just because you can almost never get your tank to that low of nutrients to stop it. So, I see no point to wasting a bunch of time killing all of the algae off the rocks and then putting it back in your tank.

 

A better way to do this is to figure out what is causing the algae in the first place and work towards eliminating or controlling it and then it will go away. I've done that with every setup I have had and once i was able to figure out what was creating it I was able to stop it dead.

 

Rich

 

I think the only way it will work is to start with dead rock like Marco Rocks. Check out Kinetic's build thread in the Elos forum on RC. He used 100% Marco Rocks and seeded without ANY live rock whatsoever (I think he actually dosed ammonia or something like that). He does not have any algae growth on his rocks even with anthias and a non-working skimmer.

[Sol]

I started my new setup with 90% base rock, the thing is no matter what you do with the rock you will still end up with algae and other stuff just because you can almost never get your tank to that low of nutrients to stop it. So, I see no point to wasting a bunch of time killing all of the algae off the rocks and then putting it back in your tank.

 

A better way to do this is to figure out what is causing the algae in the first place and work towards eliminating or controlling it and then it will go away. I've done that with every setup I have had and once i was able to figure out what was creating it I was able to stop it dead.

 

Rich

 

I'm going to have to humbly disagree here. I agree the course of action should always be to identify the problem-> identify the cause of the problem->fix said cause. However, I feel that phosphates in the rock sometimes IS the cause of the problem. For example, in one of my setups, I just couldn't get rid of an algae problem. I had 0 TDS water, an oversized skimmer, not a overly heavy load; only algae eating fish (blenny, tang etc). And yet the algae stayed. I cooked my rock, and voila. It was fixed. The conclusion I drew is pretty obvious

 

-Sol

[H20cooled]

Sol, How long has your tank been up with the cooked rocks? I think in the beginning you will see no algae for a while but as time goes by unless you actually stop what is adding the excess nutrients you will never stop algae from coming back.

 

In my last tank setup I get a bunch of algae very quick and tried everything, I had 0 TDS, HUGE skimmer, very light feeding, rinsed all food, etc and could never find a way to get rid of the Algae. Well after going through the entire setup and still not finding anything that could cause I started working backwards on my system and I realized that I had not replaced my RO/DI filters in a while. Now I was still getting a 0 TDS from them so I thought they were fine. I still didn't trust them so I replaced all the filters and within 2 weeks of doing that and a couple of water changes the algae was gone. So, I guess they were adding something to the system that was creating the algae.

 

Rich