Establishing a Healthy Microbiome in a New Aquarium Using Live Rock

Belgian Anthias

Valuable Member
View Badges
Joined
Oct 31, 2017
Messages
1,487
Reaction score
681
Location
Aarschot Belgium
Rating - 0%
0   0   0
Many timeS hobbyist confuse the microbiome bacteria with nitrifying bacteria.
while bacteria from a Bottle will seed nitrifying bacteria it will not seed the microbiome bacteria. I learned this back in the 80’s when I first used “Live” rock form the ocean. I had great success with the live rock that I didn’t with dry rock. It was due to the microbiome from the ocean.

Does it depend on what is in the bottle?
In the early days, many marine aquaria were seeded with sand from a bio-filter or another aquarium. Often garden soil bacteria were used to seed the bio-filters. Since the nineties, it is known marine nitrifiers are specific marine and a new set up aquarium should be seeded with marine bacteria. This can explain the success of introducing rock from the ocean in the eighties and nineties. Since we seed bio-filters with fresh marine life we do not use rocks from the ocean anymore to build up a reef.
 

Belgian Anthias

Valuable Member
View Badges
Joined
Oct 31, 2017
Messages
1,487
Reaction score
681
Location
Aarschot Belgium
Rating - 0%
0   0   0
Respectfully, I think you may have misread something. I used two sources of actual live rock (from the ocean). And one source of dry base rock, which as far as I can tell is exactly what youre advocating.

What does real live rock look like?


And the evidence very clearly showed that live rock produced a diverse microbial community similar to the community in an established aquarium, while the dry rock did not. The results weren't hard to see. They were pretty dramatic, in favor of the live rock.

As one grain of fresh marine sand will provoke compared to a piece of sterilised stone.

Again, where is the evidence (data on microbial communities) that dry rock becomes live rock when placed in water? I tested that statement and found it to be incorrect. Has someone else conduced an experiment with different results?

Thousands of research papers are published about remineralisation. I do not consider this a usable experiment as the result could be known before starting the experiment.
There is nothing I would be able to use as a reference.

Or are you perhaps relying on assumptions about what microbes "must be there"?

How difficult may it be to let drop 0,5 ppm ammonia to zero in a day?

A new with RO/DI water cleaned plastic 10litre bucket filled with fresh RO/DI water made seawater. Temp 20°C Add 15 drops of a 5% ammonium chloride ( NH4Cl) solution , enough for +- 0.5ppm NH4-N. Add nothing else. Ammonia NH3-N will not be measured or be less as 0.002ppm . TAN may be +- 0.5ppm. Put in an air stone for aeration and water movement. After 24 h most TAN will be used. How long will it take for all NH4-N to be used if some drops of Guillard's f/2 media are added?
No bacteria are added!
NO2 will not rise the first day although most ammonium is used up! NO2 will start to build up during the remineralization process of the during the first day produced protein.
Only heterotrophic nitrifiers get involved as long the polymers, the plastic, release organic carbon and essential building materials are available. Only after the initial heterotrophic growth starts to die off and is remineralized autotrophic nitrifiers will start building up a supportive community, a biofilm.
ref: http://www.baharini.eu/baharini/doku.php?id=nl:makazi:het_water:toevoegen_bacteriën

I just showed that you can absolutely inoculate a tank with the right bacteria, as reefers have known for decades. Using Live Rock.

The same and much better can be done with any fresh live media from the reef. Why transport rock from the other side from the planet in times the world is discussing Climat.?





With that said, I tend to agree with you about bacteria in a bottle. Wait til my next article comparing dry rock with dry rock plus bacteria in a bottle :)

What are the right microbes? That is a great question, and we don't know the complete answer. But as a starting point I suggest this: the bacterial community in a mature, thriving reef tank has the right microbes.

Also in the seventies we had thriving seawater tanks, with spawning fish, and they were seeded by marine bacteria only provided by its habitants as only sterile rock, sand, and coral skeletons were used to build the reef. The bioload was a lot higher compared to what is possible now in passively managed reef aquaria.

For a reef aquarium I would start with the coral holobiont. This includes all essential bacteria inclusive cyano, archaea, viruses, fungi, predators, etc...
What if sterile rock is used to build up the display of a new aquarium and then is first seeded with corals to avoid too much competition may prevent the installation of what is introduced.


The community in a mature reef tank is profoundly different than that in a tank full of wet base rock. But a newly established live rock tank is diverse and similar to an established tank. This is what the evidence shows.

It depends on how the wet base rock was seeded.



I'm afraid that from where I'm standing, it appears you are not a believer in the live rock data. I'm not advocating blindly following myths here, but there is pretty clear evidence that live rock produces a diverse community similar to an established aquarium, while dry rock does not. Do you have evidence to the contrary? I would be curious to read it.

I am not a believer in the live rock myth. What does the data proof? That reef rubble is different from a sterilized rock!? I really do not need any data to accept that.
I have no doubt about good " live rock" will add diversity and competition, but the question remains: Do we need rock for that? Or rubble? I think there are much better solutions to import reef diversity and for to provide the desired data.
How predictable the outcome will be when using sterilized media?

After the introduction of the first fish, everything will change. This fish has hopefully its "right" bacteria on and in him. The first time that the fish empties its intestines everything that was "right" till then will hopefully change to "right" again. The second fish will introduce more and other diversity.
 

brandon429

why did you put a reef in that
View Badges
Joined
Dec 9, 2014
Messages
30,220
Reaction score
24,063
Location
tejas
Rating - 0%
0   0   0
the practical application side of the argument is missing from your case Belgian Anthias. We need to see the tanks, or links of tanks you worked, using any arrangement. Im not saying that to deflect or add fuel, im saying as a discerning article reader I really only want to see how someone applies their science, pics or links is my only accepted validation, the description is less important. He's linked some direct tank studies with pics and inferences about invasions. literally the only way to battle it (for the betterment of science, hearty comebacks with links drives this hobby lightspeed forward) is for you to:


build a set of cheap nanos or jars and demo something with dry setups or alt-sourced setups, get pics and cause an invasion then fix it in some relevant way. Though the earth isn't marine, I think if you put a lump of sod in a marine setup somehow, someway, by some genomic inversion or changeup (is a fish changing sexes to the point of viable fecundity any less impressive) you will seed for euryhaline/multi salt level ability bacteria whereas a control jar having only saltwater, dry materials, and no direct inoculation beyond your prep contams will take much longer to demo a closed marine cycle. Your mentions I think carry weight, make them appear


make the application side of your studies appear thats what we like to see. One way to get around paying for experiments is to convince other people to run them on their tanks and report back in a thread, by this method you can literally get five thousand free inputs. You start and manage the work thread...form patterns and make predictions and we watch outcomes.

Without that, crucial proofs are missing

Make a comparable reef setup to test and improve upon current findings and link the writing back to the actual jars or nanos in the pics. that type of accountability is core/crucial vs environmental science relayed without the works. another way to instantly begin practical application is to seek out help threads in the nuisance algae or emergency forums, invasion challenge tanks, and use some aspect of your claims to attain a fix. do that ten times, earn a pattern and that's all quickly linkable for readers.
 
Last edited:
OP
OP
AquaBiomics

AquaBiomics

Active Member
View Badges
Joined
Oct 15, 2019
Messages
402
Reaction score
1,671
Rating - 0%
0   0   0
What does real live rock look like?
The properties of live rock that matter are not visible, so the question of what it "looks like" may be mostly a matter of aesthetics. Live rock A was covered with live coralline algae, tunicates, a few sponges, and even a live coral (on arrival). Looks can be deceiving. Most reefers who add live rock to their tank are doing so for the microbes, not the sponges or tunicates (most of which typically die anyway).

As one grain of fresh marine sand will provoke compared to a piece of sterilised stone.
That is a pretty extreme hypothesis, but its a testable one. Has someone tested it?

I think live sand is a perfectly good idea to inoculate the microbiome in a new tank (real live sand, not the crap on the shelf). I'm all for it. I havent seen data on this but I think it likely would work.

I think your "one grain of sand" suggestion may be a bit extreme. I'd go for a larger amount. But I am glad to see we have arrived at agreement on the value of live rock and are now only debating the size and amount of the live rock that is needed :)

How difficult may it be to let drop 0,5 ppm ammonia to zero in a day?
Thought experiments aside, my data from duplicate tanks show that a month old dry rock tank does not deplete the ammonia at anywhere near the rate you suggest. See Figure 8. It was only a 7% reduction over the course of several days, while live rock tanks depleted all of it rapidly.

The same and much better can be done with any fresh live media from the reef. Why transport rock from the other side from the planet in times the world is discussing Climat.?
I think its perfectly reasonable to propose other ways of inoculating the aquarium microbiome, and look forward to experiments toward that end. Live rock clearly works very well. The hobby can only benefit from finding additional evidence-based ways of establishing the aquarium microbiome.
 

eschaton

Active Member
View Badges
Joined
Oct 27, 2019
Messages
265
Reaction score
264
Rating - 0%
0   0   0
TBS has that live sand quality you're looking for, the true kind of sand with wigglers in it. Its the only kind of sand we dont pre-rinse in our sand rinse thread.

Out of curiousity - since I'm planning a TBS live rock purchase in the next few months - what is the grain size like in their live sand? I'd like a "sugar grain" sand bed, but I'm guessing it's a little larger grain size, and thus wouldn't make a good DSB.
 

NHgoalstop

Active Member
View Badges
Joined
Apr 8, 2019
Messages
218
Reaction score
190
Rating - 0%
0   0   0
Can you effectively seed a tank with a small piece of live rock? Or would it's microbial load not be large enough or diverse enough to seed a tank?
 

brandon429

why did you put a reef in that
View Badges
Joined
Dec 9, 2014
Messages
30,220
Reaction score
24,063
Location
tejas
Rating - 0%
0   0   0
NH I'm not sure, AB would have some nice data to make inferences from. One thing I am certain of is that all surfaces underwater coat quickly in films and various successions of bac such that no spaces are left unused, so something sure fills up all surfaces in about 76 hours onward is my guess. There might be neat ways AB could test in the future to determine rates and types that seed and take over new surface area introduced.

Eschaton
Truly I dont know but saw the tbs kind used once in a setup in the pages of the sand rinse thread, they stated motile pods were plenty but I never got follow up from them to know if it clouds upon initial setup or how it handles turbulent flow.

based on dinos invasion threads and findings here in AquaBiomics article about live rock diversity and suppression of early invasions / I feel strongly any system using live rock and sand pre loaded with marine life has the absolute best preventative arrangement we can assemble to stop dinos. I used to only believe they should be rip cleaned out of systems but work threads by Taricha and MCarroll demo'd the new way and the patterns changed my belief
 
Last edited:

rushbattle

Valuable Member
View Badges
Joined
Oct 19, 2016
Messages
1,347
Reaction score
1,647
Location
Equality
Rating - 0%
0   0   0
Can you effectively seed a tank with a small piece of live rock? Or would it's microbial load not be large enough or diverse enough to seed a tank?
In my experience, yes you can. I put a ~4 inch diameter live rock from FL, after curing a year, into my 66 gallon tank that got wet 3.5 years ago and started from dry rock. The massive cyano mats I was dealing with for years went away slowly over 4 weeks. All nutrient levels, alk, Ca, etc stayed exactly the same. I didn’t expect that result, but it is what it is I guess.
 

eschaton

Active Member
View Badges
Joined
Oct 27, 2019
Messages
265
Reaction score
264
Rating - 0%
0   0   0
I really don't understand the horror that many reefers (particularly the "dry rock contingent" react to hitchhikers with. Most hitchhikers are great, and some are almost impossible to effectively seed without introducing "bad" ones anyway.

The way I look at it, as I've said in the past, there's basically three kinds of "bad hitchhikers"
  1. Solitary opportunistic predators. Crabs, mantis shrimp, fireworms, bobbit worms, etc. Basically you just trap em once and you're done, since many of them can't even breed successfully in our tanks.
  2. Dedicated coral predators (nudis, sundial snails, red bugs, etc). Since these eat coral, they're unlikely to hitchhike in on live rock - they come in on frags instead. Regardless, even if any of them were on your live rock the easy way to get rid of them is to starve them out by not introducing coral for many months
  3. Organisms which aren't bad in and of themselves, but can reach plague proportions in tanks with high nutrient levels. Algae obviously is included here, as are things like aiptasia, vermetid snails, flatworms, etc. These sort of "pests" are often much more of a problem in tanks with low biodiversity because there aren't dozens of different life forms competing for the same niches.
 
OP
OP
AquaBiomics

AquaBiomics

Active Member
View Badges
Joined
Oct 15, 2019
Messages
402
Reaction score
1,671
Rating - 0%
0   0   0
Can you effectively seed a tank with a small piece of live rock? Or would it's microbial load not be large enough or diverse enough to seed a tank?
I havent tested this specifically but IMO it makes sense, in terms of the data on live rock by itself, that seeding a mostly dry rock tank with a little live rock would also work (probably more slowly, but I could only guess at the numbers). I have no reason to doubt the long experience of other reefers that seeding with a little live rock is useful.
 

Belgian Anthias

Valuable Member
View Badges
Joined
Oct 31, 2017
Messages
1,487
Reaction score
681
Location
Aarschot Belgium
Rating - 0%
0   0   0
I think your "one grain of sand" suggestion may be a bit extreme. I'd go for a larger amount. But I am glad to see we have arrived at agreement on the value of live rock and are now only debating the size and amount of the live rock that is needed :)

I never argued the fact so-called live rock enters some diversity. But is it the "right" one? I argue the fact that the rock used in your test will have any added value for the diversity compared to something else of marine origin which may be introduced to "improve" the microbiome. A sterilized rock will not improve a thing, for certain, exempt for providing space.


Thought experiments aside, my data from duplicate tanks show that a month old dry rock tank does not deplete the ammonia at anywhere near the rate you suggest. See Figure 8. It was only a 7% reduction over the course of several days, while live rock tanks depleted all of it rapidly.

In my example, a plastic bucket is used. The plastic delivers the carbon source. Just a test to show bacteria are everywhere and grow fast if what they need is available.
So-called live rock may release a lot of organic carbon. You used two types of "live rock", Where they tested for TOC content before use?
Was the ammonia reduced by bacteria introduced with the rock or by bacteria already present using the introduced carbon source and other nutrients? Maybe the introduced bacteria on the rock did not make it and were used as a nutrient source for bacteria already present? It just shows such a comparing test proves nothing about the value of the rock to improve diversity, it may show it improves growth rates of certain bacteria by providing nutrients for bacteria that are already present.
To make a comparable test one should now what is compared.
From the sterilized rock one may assume it contributes nothing to the microbiome but it may or may not contain usable bio-mass.
From so-called "live rock" we assume it contains bio-load, dead and alive, that it contains a microbiome. What exactly? How one may compare things of which it is not known what exactly it contains?



I think its perfectly reasonable to propose other ways of inoculating the aquarium microbiome, and look forward to experiments toward that end. Live rock clearly works very well. The hobby can only benefit from finding additional evidence-based ways of establishing the aquarium microbiome.

Inocculationg aquaria, aquaculture systems, biofilters, are been done for a very long time and have been subjected to many researchers over the past years. Recent research methods have revealed a lot of "new" players. We do have an idea of how a bio-system may be inoculated.
 

brandon429

why did you put a reef in that
View Badges
Joined
Dec 9, 2014
Messages
30,220
Reaction score
24,063
Location
tejas
Rating - 0%
0   0   0
BA
Why have you not made a simple experiment of your own, with pictures, that we can see and make our own inferences from data you generated

Don't reference a university link, make an updated study. It takes under four weeks to grow cyano mats in jars in a windowsill, cost is no factor


Will you be be creating any experiments whatsoever for us to have as a visual counterpoint

Make simple five dollar jar experiments to show inoculation or control options-keeping the systems documented and running long enough to generate primary deposits then we watch you make a change indirectly to those growths with the inoculants you recommend

Are you going to make a counter experiment, and post it
 
Last edited:
OP
OP
AquaBiomics

AquaBiomics

Active Member
View Badges
Joined
Oct 15, 2019
Messages
402
Reaction score
1,671
Rating - 0%
0   0   0
Fun discussion, thanks for all the input!
I never argued the fact so-called live rock enters some diversity. But is it the "right" one? I argue the fact that the rock used in your test will have any added value for the diversity compared to something else of marine origin which may be introduced to "improve" the microbiome.
It seems you're proposing that any object from a marine environment would do as well as live rock. How then do you explain the large differences between Live Rock A and Live Rock B in this experiment? Both came from a marine environment. They showed very large differences in microbial communities and nitrifying activities. If all that is needed is anything from the ocean, why was Live Rock A so much worse than B?

Whether the material is live rock, live sand, old pieces of shells, or a scoop of mud -- the philosophy underlying the use of live rock is to is to bring the natural marine microbes into the tank rather than hoping they'll somehow appear on their own. I could only test a few methods at once, but I think there's every reason to believe that other sources of marine microbes besides coral rubble could also be effective.

I will however point back to Live Rock A and emphasize that not every object pulled out of the ocean is equally effective in terms of introducing the microbes found in established reef tanks. That seems pretty clear from this experiment.
In my example, a plastic bucket is used. The plastic delivers the carbon source. Just a test to show bacteria are everywhere and grow fast if what they need is available.
I believe this quote highlights a misunderstanding that is central to our discussion. Yes, bacteria (and Archaea) are everywhere. The microbes that grow in a reef tank are not everywhere. You have to bring them to the tank.

Live rock has them, some live sand must have them, fish poop has a subset of them... if you live near enough to the ocean you can probably leave your tank open and catch some dust or aerosol particles with viable microbes from the ocean. But where is the evidence that these marine microbes are "everywhere"? We have people setting up reef tanks in the deserts of Arizona or the cold plains of North Dakota. I see no reason to expect, nor evidence for, the full complement of marine microbes found in established reef tank appearing in these tanks spontaneously. They have to be inoculated somehow.

So-called live rock may release a lot of organic carbon. You used two types of "live rock", Where they tested for TOC content before use?
These questions about carbon are really interesting. No, I didnt measure carbon in any way for this experiment.

It seems plausible that differences in carbon released from the live rock sources could contribute to the different communities that developed in each. Nutrient addition drives microbial blooms in the ocean, so it stands to reason any differences in nutrients resulting from dieoff of biomass on the rocks would contribute to microbial blooms in the tanks. I'll note that Live Rock A had visible surface life which died during shipping or shortly after arrival, while Live Rock B did not. Perhaps the nutrients contained within biomass in live rock contribute to differences in the quality of different live rock sources.

I don't see how you can explain the difference between live rock and dry rock as just differences in organic carbon, though. There is clear DNA evidence that adding live rock introduced many kinds of microbes (detected shortly after adding the rock) that were never detected in dry rock tanks even after a month. Water chemistry tests support the same conclusion for nitrifying microbes -- there is no evidence these were present in the dry rock tanks.

Even if we propose that live rock also contains more carbon than dry rock, we couldn't attribute the live rock effect entirely to carbon differences, right? At most, we could argue that the effects of carbon (in addition to the effects of inoculation) also contributed to the benefits of live rock. Which is an interesting and testable hypothesis that may be worth pursuing!

Was the ammonia reduced by bacteria introduced with the rock or by bacteria already present using the introduced carbon source and other nutrients? Maybe the introduced bacteria on the rock did not make it and were used as a nutrient source for bacteria already present?
This idea of "the bacteria already present" -- where is the evidence for this? I argue the relevant microbes (the kinds of microbes found in a typical reef tank, including nitrifying microbes that grow well in a saltwater environment) weren't already present. The dry rock controls show this pretty clearly, both in terms of DNA and water chemistry.

What exactly? How one may compare things of which it is not known what exactly it contains?
I sterilized the tanks, equipment, sand, and water, then added live or dry rock, then measured the microbiome shortly afterwards. Surely we can agree that the differences in microbial communities measured shortly after adding rock to these 6 identical systems resulted from the different sources of rock I added, right?
 

eschaton

Active Member
View Badges
Joined
Oct 27, 2019
Messages
265
Reaction score
264
Rating - 0%
0   0   0
Honestly, as someone who has kept a foot in the planted tank world too, this reminds me of the Walstad method of setting up planted tanks. The basis (from the book Ecology of the planted Aquarium) is basically that you use plain old potting soil as a substrate (or unsterilized pond soil if you can find it), and don't bother with CO2, ferts, or much of anything else. After a two month "breaking in" period the result is basically you end up with a very stable tank which needs minimal water changes (other than topping off) and doesn't need much done to the substrate for ten years.

Basically, this results in a diverse freshwater microbiome (since bacteria live in water films in soil even on dry land) being introduced into the tank. As opposed to the normal method of cycling a freshwater tank, which is to use semi-sterilized substrate with low levels of organics, and waits for nitrifying bacteria from the air to colonize the tank surfaces and filter media.
 

NDIrish

Well-Known Member
View Badges
Joined
Jun 27, 2019
Messages
590
Reaction score
755
Location
Jackson, TN
Rating - 0%
0   0   0
I'm in process setting up a 125 gal tall tank with mined porous reef rock (Salty bottom reef company).
I have a 40 gal tank I bought from another person who had it for about 4 years. I got the rocks, sand, water and fish. I transported everything in the water and refilled the tank with everything in the same water. The rocks have coralline growing on it and I have been dosing with vinegar.
If I put one of the rocks ( 6" l x 8"t) in my sump with a couple gallons of the water, will that give a start for my microbiome bacteria I need?
 

magikfly

Community Member
View Badges
Joined
Sep 16, 2018
Messages
84
Reaction score
53
Location
NL
Rating - 0%
0   0   0
@AquaBiomics , so now that you know which strains and in which ratio they're present on life rock how difficult would it be to assemble an additive that contains all of the spores? If it all comes down to the microbiological populations. Unless there're other factors outside of bacterial influence
 
OP
OP
AquaBiomics

AquaBiomics

Active Member
View Badges
Joined
Oct 15, 2019
Messages
402
Reaction score
1,671
Rating - 0%
0   0   0
@AquaBiomics , so now that you know which strains and in which ratio they're present on life rock how difficult would it be to assemble an additive that contains all of the spores? If it all comes down to the microbiological populations. Unless there're other factors outside of bacterial influence
I think the answer is very difficult. The rule of thumb is 99% of marine microbes can't be easily cultured. I think live rock, or other substrates (e.g sand, or artificial substrates inoculated from live rock) will remain the most effective method into the foreseeable future.
 

Cory

More than 25 years reefing
View Badges
Joined
Oct 30, 2014
Messages
6,882
Reaction score
3,137
Location
Canada
Rating - 0%
0   0   0
Great article! Looking forward to anything you do in the future.

Im curious what was the reason for the algae not growing was.
 

Belgian Anthias

Valuable Member
View Badges
Joined
Oct 31, 2017
Messages
1,487
Reaction score
681
Location
Aarschot Belgium
Rating - 0%
0   0   0
Fun discussion, thanks for all the input!

It seems you're proposing that any object from a marine environment would do as well as live rock. How then do you explain the large differences between Live Rock A and Live Rock B in this experiment? Both came from a marine environment. They showed very large differences in microbial communities and nitrifying activities. If all that is needed is anything from the ocean, why was Live Rock A so much worse than B?

Whether the material is live rock, live sand, old pieces of shells, or a scoop of mud -- the philosophy underlying the use of live rock is to is to bring the natural marine microbes into the tank rather than hoping they'll somehow appear on their own. I could only test a few methods at once, but I think there's every reason to believe that other sources of marine microbes besides coral rubble could also be effective.

I will however point back to Live Rock A and emphasize that not every object pulled out of the ocean is equally effective in terms of introducing the microbes found in established reef tanks. That seems pretty clear from this experiment.

I believe this quote highlights a misunderstanding that is central to our discussion. Yes, bacteria (and Archaea) are everywhere. The microbes that grow in a reef tank are not everywhere. You have to bring them to the tank.

Live rock has them, some live sand must have them, fish poop has a subset of them... if you live near enough to the ocean you can probably leave your tank open and catch some dust or aerosol particles with viable microbes from the ocean. But where is the evidence that these marine microbes are "everywhere"? We have people setting up reef tanks in the deserts of Arizona or the cold plains of North Dakota. I see no reason to expect, nor evidence for, the full complement of marine microbes found in established reef tank appearing in these tanks spontaneously. They have to be inoculated somehow.


These questions about carbon are really interesting. No, I didnt measure carbon in any way for this experiment.

It seems plausible that differences in carbon released from the live rock sources could contribute to the different communities that developed in each. Nutrient addition drives microbial blooms in the ocean, so it stands to reason any differences in nutrients resulting from dieoff of biomass on the rocks would contribute to microbial blooms in the tanks. I'll note that Live Rock A had visible surface life which died during shipping or shortly after arrival, while Live Rock B did not. Perhaps the nutrients contained within biomass in live rock contribute to differences in the quality of different live rock sources.

I don't see how you can explain the difference between live rock and dry rock as just differences in organic carbon, though. There is clear DNA evidence that adding live rock introduced many kinds of microbes (detected shortly after adding the rock) that were never detected in dry rock tanks even after a month. Water chemistry tests support the same conclusion for nitrifying microbes -- there is no evidence these were present in the dry rock tanks.

Even if we propose that live rock also contains more carbon than dry rock, we couldn't attribute the live rock effect entirely to carbon differences, right? At most, we could argue that the effects of carbon (in addition to the effects of inoculation) also contributed to the benefits of live rock. Which is an interesting and testable hypothesis that may be worth pursuing!


This idea of "the bacteria already present" -- where is the evidence for this? I argue the relevant microbes (the kinds of microbes found in a typical reef tank, including nitrifying microbes that grow well in a saltwater environment) weren't already present. The dry rock controls show this pretty clearly, both in terms of DNA and water chemistry.


I sterilized the tanks, equipment, sand, and water, then added live or dry rock, then measured the microbiome shortly afterwards. Surely we can agree that the differences in microbial communities measured shortly after adding rock to these 6 identical systems resulted from the different sources of rock I added, right?

To prove and compare something one has to start from a known situation.
In the case, one has to start by identifying the micro-organisms on the different rocks before introduction, as they will be from different strains as those already present or introduced by other means. Otherwise one can not prove a thing. They should be of marine origin, marine strains, which may not be the case for most bacteria and archaea present on a rock which has been exposed to air and sunlight for an unknown period of time, stocked in a dirty container and even may have been exposed to rain, cleaned by a hose using source- or tap water, transported in a used newspaper and then end up in artificial seawater full with active competition for the available nutrients. Who will tell?
Bacteria in sleeping mode may have it very difficult to come out of the lag phase and to compete for the same nutrients and be unable to start up log phase. Maybe the so-called "live rock" will not introduce to the marine environment adjusted life at all or just very few families of marine bacteria and only some heterotrophs as most autotrophs may not survive as they do not form endospores. A variety of different microorganisms form "spores" or "cysts", but the endospores of low G+C Gram-positive bacteria are by far the most resistant to harsh conditions. Maybe only those marine specimen may have survived and may be found after the introduction?
Marine Autotrophs may have used its stringent response due to sudden environment changes but will not come out of lag phase after a period of time as they will have used up their reserves stored to do so. Most of essential marine micro-life may have been replaced by non-marine competitors before the introduction to your tank.
Also, the available nutrient content on the rock is important as it may influence the growth rates of specific bacteria, out-competing others.

Sequencing the different strains for marine origin may provide proof. For example the presence of marine nitrifiers on such " live rock". Very difficult and very expensive.

It would be interesting to know what is introduced exactly if imported so-called " live rock" is used and how "marine" the diverse population still is.

I have no doubt a piece of base rock which has been in a sump of a flourishing reef tank for a period of time and is used to seed an aquarium will add a lot more valuable diversity as any imported so-called " live rock".

To set up and seed a new reef aquarium, why not start by introducing a few coral holobiont firsthand, before introducing other real marine competitors.? OLD school, as only bleached and sterilized aragonite or calcite based rock will be used. Seeding an aquarium takes at least a few months anyway. Each introduction of marine life will add new valuable competitors, they will be beneficial for something. Each coral, each organism, will introduce specific strains of micro-organisms, needed for their survival.
 
Back
Top