Is nutrient control an effective method of treating algae in a reef?

[Belgian Anthias]

My main reason to not use a UV is that I did not want to kill the bacteria that are present in the water. I choose to increase them with organic carbon dosing, and I'd prefer those that are suspended in the water to be skimmed out or eaten whole by various organisms, rather than break apart after passing through a UV, spilling their guts back into the water.

A UV unit in line will not reduce the bacterial population present in the aquarium! The decaying biomass will provide the nutrients for other bacterial growth. Live bacteria are not skimmed but some may be carried out on the foam. This process is known to be selective as some strains are carried out easily, others are not, giving the change to a selective bunch to evolve and adapt while competitors are removed. A by most users underestimated but important issue on the negative side of using a skimmer. Using UV cleaned water in a refuge containing the skimmer will avoid this. Also when eaten by other organisms most of there guts will be spilled back into the water while passing through the food chain and by the end user. When UV sterilized water is entered into the aquarium it will be colonised again in no time. Increasing the population by carbon dosing does increase the bacterial evolution issue, the selective cultivation of strains of bacteria.

 

[Belgian Anthias]

https://www.researchgate.net/public...goon_2001-2010_and_its_relation_to_macroalgae

Thank You
Bedankt!

 

[Randy Holmes-Farley]

A UV unit in line will not reduce the bacterial population present in the aquarium! The decaying biomass will provide the nutrients for other bacterial growth. Live bacteria are not skimmed but some may be carried out on the foam. This process is known to be selective as some strains are carried out easily, others are not, giving the change to a selective bunch to evolve and adapt while competitors are removed. A by most users underestimated but important issue on the negative side of using a skimmer. Using UV cleaned water in a refuge containing the skimmer will avoid this. Also when eaten by other organisms most of there guts will be spilled back into the water while passing through the food chain and by the end user. When UV sterilized water is entered into the aquarium it will be colonised again in no time. Increasing the population by carbon dosing does increase the bacterial evolution issue, the selective cultivation of strains of bacteria.

While I do not agree with everything you said, nothing you said seems to dispute my reason for not wanting to use a UV.

 

[Belgian Anthias]

FWIW, I will also add they I think their comment about an infinite supply in the ocean is misguided and makes no sense.

It was suggested as part of an explanation of why 0.1 ppm nitrate might be OK in the ocean but not necessarily in a reef tank. As if the volume of the ocean can make up for the low concentration.

I don't see how that makes sense. Differences in flow rate might make sense to explain why corals might take up more nitrate from 0.1 ppm nitrate in the ocean than in a reef tank, if a coral actually depleted the nitrate from the volume around them, but whether there is extra nitrate twelve feet away or not is meaningless to a coral.

At the same nutrient levels the total water volume surrounding the coral will be determinant for its growth prospectives. If I was a coral I would rather be in the ocean.

 

[Belgian Anthias]

While I do not agree with everything you said, nothing you said seems to dispute my reason for not wanting to use a UV.

Using UV will avoid selective ( unknown) bacterial evolution in a closed system, using a skimmer and carbon dosing without UV will promote selective bacterial evolution. The way a closed bio-system is managed may influence the future of the hobby. If I decide to use a skimmer I would certainly use it in combination with UV. Certainly until it is known what we are doing exactly.

 

[Subsea]

Using UV will avoid selective ( unknown) bacterial evolution in a closed system, using a skimmer and carbon dosing without UV will promote selective bacterial evolution. The way a closed bio-system is managed may influence the future of the hobby. If I decide to use a skimmer I would certainly use it in combination with UV. Certainly until it is known what we are doing exactly.

Ken Felderman articles on carbon dosing postulated that skimmers skew bacteria population. Considering that on the reef, bacteria transport 60% of reef nutrients; Felderman postulated that skewed bacteria populations could be the cause of “old tank syndrome”.

 

[Randy Holmes-Farley]

Using UV will avoid selective ( unknown) bacterial evolution in a closed system, using a skimmer and carbon dosing without UV will promote selective bacterial evolution. The way a closed bio-system is managed may influence the future of the hobby. If I decide to use a skimmer I would certainly use it in combination with UV. Certainly until it is known what we are doing exactly.

Maybe. Is the selective evolution good or bad? I think you'd find it impossible to prove one way or the other.

 

[Subsea]

At the same nutrient levels the total water volume surrounding the coral will be determinant for its growth prospectives. If I was a coral I would rather be in the ocean.

I find this analogy of reefs in the wild to be near zero nutrients to be misleading. It depends on what is being measured. If you consider the “microbial loop”in which bacteria move nutrients from one food web to another, there is plenty of food for corals.

 

[mcarroll]

Ken Felderman articles on carbon dosing postulated that skimmers skew bacteria population. Considering that on the reef, bacteria transport 60% of reef nutrients; Felderman postulated that skewed bacteria populations could be the cause of “old tank syndrome”.

I suspect due to the fact that we're only thinking in terms of bacteria that in actuality the effect being described also holds for a multitude of other (dis)associated microbes. This potentially goes to the heart of system stability.

Therefore I think I'm with Ken on this theory. (Next step: define "old tank syndrome" )

Whether proven true or false in the end, the observations made around such a theory would be very educational.

$40 mail-in BLAST analysis anyone? Anyone? Anyone?

 

[Belgian Anthias]

Maybe. Is the selective evolution good or bad? I think you'd find it impossible to prove one way or the other.

There is nothing to prove. When proven it is to late. It is a question of responsible reef keeping and common sense. By using UV sterilized water for feeding the skimmer selective removal of live bacteria is avoided. Not using a skimmer avoids the necessity for UV.

 

[mcarroll]

Effects similar to protein skimming are not unheard of on real reefs, so I'm not sure I'm willing to say it's more than an interesting (even if probable) theory.

Real reef ecosystems certainly have some capacity for resisting these effects.

And there are lotsa nice home reefs running skimmers out there....nearly 100% of the oldest, nicest reefs, in fact.

Go figure.

 

[Subsea]

https://www.researchgate.net/public...goon_2001-2010_and_its_relation_to_macroalgae

In the last ten years I have been an amateur seaweed farmer. I say amateur because I didn’t make money. It was fun and it keeps me busy since retiring from deep water drilling. For certain, seaweed is a sponge and absorbs what’s in the water. Initially, I grew red ogo, Gracilaria Parvispora, then Gracilaria Tikvahiae, using air tumble culture. My makeup water comes from a limestone aquifier which was the bottom of an ancient sea in geologic past. I never considered the high sulfur content of the water until I tasted Red Ogo. Instead of a crisp sweet crunch the Ogo was bitter. The nitrogenhosphate ratio was 30:1

Not conclusive, but I have found that elevated nitrate levels favor desirable macro over turf and hair algae.

https://academic.oup.com/femsec/article/88/2/213/467628

After reading this article, one realizes the complexity of the interconnected ecosystem between algae and bacteria.

“Quorum sensing bacteria cover macro surfaces then alter dna signaling to optimize their growth. Because of the holistic nature of the coral holobiont, researchers are finding how complex and interconnected the marine environment is.”

 

[Subsea]

I suspect due to the fact that we're only thinking in terms of bacteria that in actuality the effect being described also holds for a multitude of other (dis)associated microbes. This potentially goes to the heart of system stability.

Therefore I think I'm with Ken on this theory. (Next step: define "old tank syndrome" )

Whether proven true or false in the end, the observations made around such a theory would be very educational.

$40 mail-in BLAST analysis anyone? Anyone? Anyone?

You are right about terminology being precise. In a general way, I equate “old tank syndrome” with a climax forest. After an evolution of competing species with a natural progression toward a dominant species is what I understand “old tank syndrome to mean.

 

[Belgian Anthias]

I find this analogy of reefs in the wild to be near zero nutrients to be misleading. It depends on what is being measured. If you consider the “microbial loop”in which bacteria move nutrients from one food web to another, there is plenty of food for corals.

In the last ten years I have been an amateur seaweed farmer. I say amateur because I didn’t make money. It was fun and it keeps me busy since retiring from deep water drilling. For certain, seaweed is a sponge and absorbs what’s in the water. Initially, I grew red ogo, Gracilaria Parvispora, then Gracilaria Tikvahiae, using air tumble culture. My makeup water comes from a limestone aquifier which was the bottom of an ancient sea in geologic past. I never considered the high sulfur content of the water until I tasted Red Ogo. Instead of a crisp sweet crunch the Ogo was bitter. The nitrogenhosphate ratio was 30:1

Not conclusive, but I have found that elevated nitrate levels favor desirable macro over turf and hair algae.

https://academic.oup.com/femsec/article/88/2/213/467628

After reading this article, one realizes the complexity of the interconnected ecosystem between algae and bacteria.

“Quorum sensing bacteria cover macro surfaces then alter dna signaling to optimize their growth. Because of the holistic nature of the coral holobiont, researchers are finding how complex and interconnected the marine environment is.”

Also corals have microbial interactions with coral associated bacteria.

 

[Subsea]

Also corals have microbial interactions with coral associated bacteria.

In an isolated laboratory experiment, it was shown that coral selectively harvested only certain bacteria (I assume by size), then produced a growth enzyme to target feed that specific bacteria species. Did coral just manipulate its environment?

 

[Hans-Werner]

Regarding the bacteria the excretions of corals support different bacteria than the excretions of algae as this article shows. While algae excrete labile sugars that are very rapidly degraded by bacteria corals excrete semi-labile substances that are degraded more slowly by different kinds of bacteria. The bacteria that live on the labile sugars are potential pathogens of corals and maybe fish and crustaceans.

In my experience the bacteria that grow with glucose or other labile forms of organic carbon dosing excrete more slime than the slower growing bacteria. This can be seen on the glasses of the tank. This slime forms foam with air and feeds the skimmer. Maybe bacteria that excrete more slime are skimmed better and in this way the selective skimming of slime forming bacteria is a great advantage. Maybe because of this the skimmer is such a proven device for water treatment.

 

[Scrubber_steve]

Regarding the bacteria the excretions of corals support different bacteria than the excretions of algae as this article shows. While algae excrete labile sugars that are very rapidly degraded by bacteria corals excrete semi-labile substances that are degraded more slowly by different kinds of bacteria. The bacteria that live on the labile sugars are potential pathogens of corals and maybe fish and crustaceans.

The Hass et al article deals with “shift in ecosystem trophic structure towards higher microbial biomass”, the potential cause of this is “overfishing and eutrophication, both of which facilitate enhanced growth of fleshy algae” and the “DOC released by ungrazed fleshy algae” specifically.

This type of algae is a slow metaboliser (slow growing) & leaks a high percentage of its carbon uptake as exudate (DOC) back into the water. It should be mentioned that algaes typically used in aquaria for filtration purposes are fast metabolisers (fast growing) & leak a very small percentage of their carbon uptake back into the water as exudate. Regarding this, another Hass article, using the exudate from these fast metabolising algae for bacterial growth resulted in “low bacterial cell yields” whereas the “ungrazed fleshy algae” types produced “high bacterial yields”.
So algae ain’t algae, & care should be taken not to place all algae into the same box.

In my experience the bacteria that grow with glucose or other labile forms of organic carbon dosing excrete more slime than the slower growing bacteria. This can be seen on the glasses of the tank. This slime forms foam with air and feeds the skimmer. Maybe bacteria that excrete more slime are skimmed better and in this way the selective skimming of slime forming bacteria is a great advantage. Maybe because of this the skimmer is such a proven device for water treatment.

Few aquariums would contain the "ungrazed fleshy algae” types; and how many people dose glucoses as a carbon source for nutrient control? What then would be this "liable" food source for these 'slimy bacteria' colonies?

 

[Hans-Werner]

Acetate and Ethanol maybe? Both can be metabolized very quickly and are definitely labile organic carbon. Of course I don´t know for sure the exact kind of bacteria they are feeding.

The article reports the excretion of labile organic matter about turf algae:
"Microbial abundances increase with reef algal cover. The
observation of ‘more DOC gives less DOC’ can be attributed to
priming27,28, where labile DOC from the turf and fleshy
macroalgae stimulate microorganism to remineralize semi-labile
DOC pools."

Can you please link the article you mean, Steve?

 

[Scrubber_steve]

Regarding the bacteria the excretions of corals support different bacteria than the excretions of algae as this article shows. While algae excrete labile sugars that are very rapidly degraded by bacteria corals excrete semi-labile substances that are degraded more slowly by different kinds of bacteria. The bacteria that live on the labile sugars are potential pathogens of corals and maybe fish and crustaceans.

In my experience the bacteria that grow with glucose or other labile forms of organic carbon dosing excrete more slime than

Can you please link the article you mean, Steve?

Just cooking dinner now; I'll be back

 

[Scrubber_steve]

The article reports the excretion of labile organic matter about turf algae:
"Microbial abundances increase with reef algal cover. The
observation of ‘more DOC gives less DOC’ can be attributed to
priming27,28, where labile DOC from the turf and fleshy
macroalgae stimulate microorganism to remineralize semi-labile
DOC pools."

Can you please link the article you mean, Steve?

True turf algaes are an important source of food on the reefs. Whether or not their exudates are virulent bacteria food I believe is debateable,
& in any case, they are only a potential problem if over fishing has reduced the population size, & diversity of herbivorous fish, or disease of herbivorous invertebrates like urchins.
True turf algaes are not used in filtration to the best of my knowledge, despite the term > Turf algae scrubber. Ulva is the norm for scrubbers, & chaeto for fuges.

Hass' paper http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0027973

Note, "high rates of DOC release" refer to fast metabolising algae, despite their low percentage leak of exudates
See Discussion
Variations in DOC quality and microbial response among algal exudates

Notably, bacterioplankton growth rates and yields were uncorrelated with DOC release rates, emphasizing that these patterns in efficiency were not solely driven by the absolute quantity of cells produced, but also by the utilization of the DOM exuded.

Among the algae, Turbinaria exhibited relatively low bacterial cell yields and specific DOC removal rates, despite having relatively high rates of DOC release, translating into significantly reduced bacterial growth efficiency.

In contrast, Halimeda exhibited one of the lowest rates of DOC production and much lower DOC release ratios than the other organisms, but the produced DOC exhibited relatively high bacterial yields translating into significantly higher growth efficiencies than the other treatments.

These patterns in the efficiency of production and removal of DOC together suggest that Turbinaria has relatively low-quality DOC (i.e. low growth efficiency)
and Halimeda relatively high-quality DOC (i.e. high growth efficiency) compared with other benthic producers examined here.

We also note that Amansia appeared to produce large amounts of highly labile DOC with low bacterial growth efficiencies, suggesting selection for a highly inefficient community growing on the rapidly exuded compounds