How to FEED your reef tank so that your corals will really GROW, instead of ho-hum...
- Thread starter capecoral
- Start date
"[A little more background on DOC; it is usually "limiting" in reef waters, meaning that bacteria would consume much more of it, and thus the bacteria would grow to much larger numbers, if more DOC were available. Corals, of course, would consume much more DOC and bacteria if either one were available. So it is important to remember that not only does DOC/DOM not build up in reef or aquarium water, it is actually kept low by the bacteria, and also by the high concentration of corals that some reefers keep in their tanks. More DOC (and bacteria) would be beneficial.]"
"Phytoplankton exudation of organic matter: Why do healthy cells do it? American Society of Limnology and Oceanography, 1988."
"Although the reality of exudation from active phytoplankton [algae] cells seems to be generally accepted, understanding the physiological mechanism behind it [in 1988] is still lacking. Exudation has been implicitly interpreted as the active release of excess photosynthates [DOC] that accumulate when carbon fixation [photosynthesis] exceeds incorporation into new cell material [algae growth]."
"Phytoplankton exudates are rapidly used by planktonic bacteria, which are [also] able to take up inorganic nutrients more efficiently than phytoplankton [and this further helps reduce nitrate and phosphate]."
"Phytoplankton are often dominated by a wide range of low molecular weight compounds, including amino acids with high amounts of nitrogen."
"Several studies on the uptake of radio-labeled compounds [algae exudates] by natural plankton assemblages [zooplankton] have shown bacterioplankton to be responsible for the entire uptake of the [...] organic compounds. This observation is as expected if the exudates are rapidly dispersed, because bacteria account for most of the overall [algal] cell surface in natural planktonic communities."
"Extracellular organic carbon (EOC) released by phytoplankton and bacterial production. Oikos, 1985"
"Parts of the pelagic [water column] carbon cycle were investigated during ten [daily] cycles in five Danish lakes and one coastal area. The study included simultaneous measurements of primary production, phytoplankton release, and bacterial assimilation of extracellular organic carbon (EOC) [DOC], bacterial production and bacterial assimilation of dissolved free amino acids. The primary production, EOC release, and assimilation were measured with the carbon-14 method and a particle-size fractionation. The gross release of EOC [DOC] ranged from 5 to 46 percent of the [daily] primary production, and the major part of the released products were assimilated by bacteria. [...] In the lakes the assimilation of EOC [DOC] contributed substantially (greater than 80 percent) to the bacterial production in three cases, moderately (38 to 50 percent) in three cases, and was of less (less than 38 percent) importance in one case."
"Utilization of dissolved organic carbon from different sources by pelagic bacteria in an acidic mining lake. Archiv für Hydrobiologie, 2006"
"We compared growth rates and efficiencies of pelagic [water column] bacteria from an extremely acidic mining lake (pH 2.6, mean depth 4.6 meters), supplied with different sources of carbon [DOC]: (1) excreted by phytoplankton, (2) derived from benthic [sea floor] algae, (3) entering the lake via ground water, and (4) leached from leaf litter. Bacteria exhibited high growth rate and efficiency on exudates of pelagic and benthic algae. In contrast, they showed a lower growth rate and efficiency with organic carbon from ground water, and grew at a very high rate but a very low efficiency on leaf leachate. Results from stable isotope analyses indicate a greater importance of benthic exudates [DOC from solid algae] and leaf leachate for bacteria in the [upper layer of water], and a higher impact of ground water sources in the [lower layers of water]. Given the magnitude of differential source inputs into the lake, we suggest that benthic primary production was the most important carbon source for pelagic bacteria. [i.e., bacteria prefer to consume DOC from "solid" algae, compared to phytoplankton]"
"Phytoplankton exudation of organic matter: Why do healthy cells do it? American Society of Limnology and Oceanography, 1988."
"Although the reality of exudation from active phytoplankton [algae] cells seems to be generally accepted, understanding the physiological mechanism behind it [in 1988] is still lacking. Exudation has been implicitly interpreted as the active release of excess photosynthates [DOC] that accumulate when carbon fixation [photosynthesis] exceeds incorporation into new cell material [algae growth]."
"Phytoplankton exudates are rapidly used by planktonic bacteria, which are [also] able to take up inorganic nutrients more efficiently than phytoplankton [and this further helps reduce nitrate and phosphate]."
"Phytoplankton are often dominated by a wide range of low molecular weight compounds, including amino acids with high amounts of nitrogen."
"Several studies on the uptake of radio-labeled compounds [algae exudates] by natural plankton assemblages [zooplankton] have shown bacterioplankton to be responsible for the entire uptake of the [...] organic compounds. This observation is as expected if the exudates are rapidly dispersed, because bacteria account for most of the overall [algal] cell surface in natural planktonic communities."
"Extracellular organic carbon (EOC) released by phytoplankton and bacterial production. Oikos, 1985"
"Parts of the pelagic [water column] carbon cycle were investigated during ten [daily] cycles in five Danish lakes and one coastal area. The study included simultaneous measurements of primary production, phytoplankton release, and bacterial assimilation of extracellular organic carbon (EOC) [DOC], bacterial production and bacterial assimilation of dissolved free amino acids. The primary production, EOC release, and assimilation were measured with the carbon-14 method and a particle-size fractionation. The gross release of EOC [DOC] ranged from 5 to 46 percent of the [daily] primary production, and the major part of the released products were assimilated by bacteria. [...] In the lakes the assimilation of EOC [DOC] contributed substantially (greater than 80 percent) to the bacterial production in three cases, moderately (38 to 50 percent) in three cases, and was of less (less than 38 percent) importance in one case."
"Utilization of dissolved organic carbon from different sources by pelagic bacteria in an acidic mining lake. Archiv für Hydrobiologie, 2006"
"We compared growth rates and efficiencies of pelagic [water column] bacteria from an extremely acidic mining lake (pH 2.6, mean depth 4.6 meters), supplied with different sources of carbon [DOC]: (1) excreted by phytoplankton, (2) derived from benthic [sea floor] algae, (3) entering the lake via ground water, and (4) leached from leaf litter. Bacteria exhibited high growth rate and efficiency on exudates of pelagic and benthic algae. In contrast, they showed a lower growth rate and efficiency with organic carbon from ground water, and grew at a very high rate but a very low efficiency on leaf leachate. Results from stable isotope analyses indicate a greater importance of benthic exudates [DOC from solid algae] and leaf leachate for bacteria in the [upper layer of water], and a higher impact of ground water sources in the [lower layers of water]. Given the magnitude of differential source inputs into the lake, we suggest that benthic primary production was the most important carbon source for pelagic bacteria. [i.e., bacteria prefer to consume DOC from "solid" algae, compared to phytoplankton]"
"[This next-to-last focus on DOC uses amino acids as the research topic. Amino's are one of the DOC's that feed corals directly, and also indirectly via bacteria and microbe growth, and thus are kept at low levels in reef waters.]"
"Close coupling between release and uptake of dissolved free amino acids in seawater studied by an isotope dilution approach. Marine Ecology Progress Series, 1987"
"Dissolved free amino acids (DFAAs) play a major role in the [movement] of organic carbon and nitrogen in marine biotic systems. In this study, DFAA release and uptake rates in samples from Long Island Sound and the Atlantic continental shelf were measured [...]. Numerous measurements over a 20 month period showed that release and uptake rates were usually similar, and net changes in DFAA concentration were much slower than (typically less than 30 percent of) the gross uptake or release rates; this indicates close coupling between these two processes. DFAA turnover was rapid, with summer turnover times typically 0.5 hours or less, and concentrations of individual DFAAs were usually a few nanomolar [this means the entire amount of amino DOC's are consumed in 30 minutes]. Comparisons of total uptake rates with estimates of bacterial heterotrophic production confirm that DFAAs represent a significant source (greater than 10 percent) of carbon and nitrogen for bacterial growth. DFAA release, mediated by copepods either through 'sloppy feeding' or by excretion, can be of comparable magnitude to direct release by microplankton."
"In recent years [1987] it has been found that as much as 60 percent of total primary production in planktonic marine ecosystems cycles through bacterioplankton [the carbon cycle], primarily via dissolved organic matter (DOM). Uptake of DOM has been studied for many years; however it is probably the rate of release of DOM that controls the amount available to bacteria, so understanding the release processes is an important goal."
"In experiments with copepods, these animals were collected from Long Island Sound with a plankton net, and swimming individuals of the species Acartia tonsa were picked out by pipette and manipulated with acid washed nitex netting."
"Copepods released DFAAs, both in the presence and absence of other smaller plankton, but the release rate was higher when there were microplankton available for copepod feeding."
"As the building blocks of proteins, DFAAs are one of the largest single classes of monomers used by all organisms, making them important sources of carbon and nitrogen for bacteria. [Thus they are eaten rapidly by bacteria]"
"The copepod experiments were designed to see if processes related to zooplankton feeding have an effect on DFAA release. The results showed that the combination of copepods+food had a much higher release rate than either one alone. This suggests that the processes of 'sloppy feeding', ingestion, and egestion cause release of DFAAs into seawater [by the copepods]."
"It was a general phenomenon in virtually all of our experiments that the net changes in DFAA concentrations were very slow (30 percent or less) compared to the gross release and uptake rates. In other words, the bacterial DFAA utilization rates closely corresponded to the rates at which the DFAAs were released, so the DFAAs neither accumulated nor disappeared appreciably compared to the changes one would expect from release or uptake alone. Similar results were found when DFAA release and uptake were measured at much shorter intervals over [daily] cycles. This suggests good regulatory mechanisms whereby the bacteria use the DFAAs as rapidly as they become available."
"Close coupling between release and uptake of dissolved free amino acids in seawater studied by an isotope dilution approach. Marine Ecology Progress Series, 1987"
"Dissolved free amino acids (DFAAs) play a major role in the [movement] of organic carbon and nitrogen in marine biotic systems. In this study, DFAA release and uptake rates in samples from Long Island Sound and the Atlantic continental shelf were measured [...]. Numerous measurements over a 20 month period showed that release and uptake rates were usually similar, and net changes in DFAA concentration were much slower than (typically less than 30 percent of) the gross uptake or release rates; this indicates close coupling between these two processes. DFAA turnover was rapid, with summer turnover times typically 0.5 hours or less, and concentrations of individual DFAAs were usually a few nanomolar [this means the entire amount of amino DOC's are consumed in 30 minutes]. Comparisons of total uptake rates with estimates of bacterial heterotrophic production confirm that DFAAs represent a significant source (greater than 10 percent) of carbon and nitrogen for bacterial growth. DFAA release, mediated by copepods either through 'sloppy feeding' or by excretion, can be of comparable magnitude to direct release by microplankton."
"In recent years [1987] it has been found that as much as 60 percent of total primary production in planktonic marine ecosystems cycles through bacterioplankton [the carbon cycle], primarily via dissolved organic matter (DOM). Uptake of DOM has been studied for many years; however it is probably the rate of release of DOM that controls the amount available to bacteria, so understanding the release processes is an important goal."
"In experiments with copepods, these animals were collected from Long Island Sound with a plankton net, and swimming individuals of the species Acartia tonsa were picked out by pipette and manipulated with acid washed nitex netting."
"Copepods released DFAAs, both in the presence and absence of other smaller plankton, but the release rate was higher when there were microplankton available for copepod feeding."
"As the building blocks of proteins, DFAAs are one of the largest single classes of monomers used by all organisms, making them important sources of carbon and nitrogen for bacteria. [Thus they are eaten rapidly by bacteria]"
"The copepod experiments were designed to see if processes related to zooplankton feeding have an effect on DFAA release. The results showed that the combination of copepods+food had a much higher release rate than either one alone. This suggests that the processes of 'sloppy feeding', ingestion, and egestion cause release of DFAAs into seawater [by the copepods]."
"It was a general phenomenon in virtually all of our experiments that the net changes in DFAA concentrations were very slow (30 percent or less) compared to the gross release and uptake rates. In other words, the bacterial DFAA utilization rates closely corresponded to the rates at which the DFAAs were released, so the DFAAs neither accumulated nor disappeared appreciably compared to the changes one would expect from release or uptake alone. Similar results were found when DFAA release and uptake were measured at much shorter intervals over [daily] cycles. This suggests good regulatory mechanisms whereby the bacteria use the DFAAs as rapidly as they become available."
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"[In this last focus on DOC, the point is hopefully made that DOC is kept at low levels in water due to the consumption by planktonic bacteria, i.e, the bacteria in the water column. If a new source of DOC emerges which tries to increase DOC levels, bacterial growth increases too, keeping the DOC in check. The bacteria, of course, then feed the rest of the food chain which feeds the corals. And this is in addition to the bacteria and DOC feeding the corals directly.]"
"Biomass, production and heterotrophic activity of bacterioplankton in the Great Astrolabe Reef lagoon (Fiji). Coral Reefs, 1999."
"Biomass, production and heterotrophic [eating] activity of bacterioplankton were determined for two weeks in the Great Astrolabe Reef lagoon, Fiji. Bacteria and bacterial activities were distributed homogeneously throughout the water column (20 to 40 meters deep), and varied little from site to site inside the lagoon. [...] Growth efficiency, determined by correlating the net increase of bacterial biomass, and the net decrease of dissolved organic carbon (DOC) in dilution cultures, was very low (average 6.6 percent). [...]. The turn-over rate of DOC due to bacterial consumption was estimated to be 0.048 per day during the period of study. [About 5 percent of DOC was consumed each day]"
"Planktonic bacteria make important contributions to the bio-geochemical cycles of marine pelagic [water column] ecosystems. In most oceanic environments, bacterial production [growth] represents a significant proportion of primary production [although it is actually "secondary production"], and in the most [low dissolved nutrient] environments, bacterial biomass may even exceed phytoplankton biomass. In coral reef environments, bacterioplankton have been studied mostly in the water column overlying coral reefs, while atoll and island lagoons have received less attention. Atoll and island lagoons may, however, represent large bodies of water where heterotrophic bacterioplankton with low carbon-to-nitrogen ratios relative to the phytoplankton, could be an important contributor to particulate nitrogen [amounts]. Nutrient recycling is essential in coral reef areas [no relying on water changes], often characterized by low concentrations and inputs of new nutrients. Hence, the understanding of bacterioplankton dynamics is essential to studies of carbon and nutrient cycling in coral reef environments."
"Vertical and spatial distributions of bacterioplankton abundance and production were investigated during a two week cruise on the ORSTOM R/V Alis from 18 to 29 May 1994. [...] Free and attached bacterioplankton, production, and dissolved organic carbon were determined in selected samples."
"Bacterioplankton carbon growth yield (CGY) was estimated for the same cultures by correlating DOC consumption with the increase of bacterial biomass."
"DOC concentrations decreased significantly (see figure 4) within the cultures, while bacterial [mass] increased."
"The whole heterotrophic bacterioplankton community (free + attached) had an average specific growth rate of 0.282 per day, and therefore an average generation time of 1/0.282 = 3.6 days."
"Total DOC turnover [elimination] due to bacterioplankton consumption may be estimated from bacterial production (BP) and bacterioplankton carbon growth yield (CGY) determined in the two dilution cultures. Bacterial carbon consumption (BCC) would thus equal BP/CGY. With an average BP of 0.36 ug-at carbon per liter per day, and a CGY of 6.6 percent, BCC equals 0.36/0.066 = 5.5 ug-at carbon per liter per day. Hence, DOC turn-over rate equals 5.5/114 = 0.048 per day, and total DOC turn-over time is 1/0.048 = 21 days [for complete consumption]."
"The two independent determinations allowed the estimation of an average CGY of 6.6 percent. [...] This low CGY value determined in the present study could be interpreted as an index of severe bottom-up limitation of bacterioplankton [i.e., the DOC, which is the food source for the bacteria, is not nearly enough to allow the bacteria to continue growing]."
"The average generation time for the whole bacterioplanktonic community was 3.6 days. This is quite long compared to those estimated over coral reefs, but is in agreement with those determined in atoll lagoons. This long generation time could be explained by a resource limitation of bacteria [not enough DOC to be consumed]."
"Bacterioplankton demand for DOC was estimated to average 5.4 ug-at carbon per liter per day for the period of study. Integrated from the surface to the bottom of the lagoon, the average demand for the 10 stations investigated was 126 mg-at carbon per square meter per day, and was therefore nearly equal to primary production [by algae] during the same period. The net production of bacterial biomass was low compared to particulate primary production (8 percent), but the low estimated growth yield shows that the heterotrophic activity of bacteria was nearly equivalent to primary production. This confirms the importance of bacterioplankton to the remineralization processes in the water column of coral reef lagoons. ["Remineralization" is the conversion of organics, like DOC, into inorganics like nitrate and phosphate]"
"While bacterial growth rates have been frequently reported to be higher inside island or atoll lagoons than in surrounding oceanic waters, lagoon DOC concentrations may be similar, as in this work, or even lower than those of oceanic waters."
"In conclusion, in the Great Astrolabe Reef lagoon, [...] bacterial biomass constituted a significant proportion of POC, and was in the same range as phytoplankton biomass. Heterotrophic demand was of the same order as primary production. The low average growth rate for the bacterioplanktonic community, at an average temperature of about 28 C, and the poor carbon growth yield (6.6 percent), both suggest bacterioplankton to be resource-limited in this lagoon. [...] All these features are consistent with a bottom-up limitation of bacterioplankton."
"[For those interested in a book about DOC, the one to get would be 'Aquatic Ecosystems: Interactivity Of Dissolved Organic Matter', which talks about the types of studies we have covered here, for both fresh and saltwater. It is available as a hardcover book and also as individual PDF chapters:
http://www.sciencedirect.com/science/book/9780122563713 ]"
"Biomass, production and heterotrophic activity of bacterioplankton in the Great Astrolabe Reef lagoon (Fiji). Coral Reefs, 1999."
"Biomass, production and heterotrophic [eating] activity of bacterioplankton were determined for two weeks in the Great Astrolabe Reef lagoon, Fiji. Bacteria and bacterial activities were distributed homogeneously throughout the water column (20 to 40 meters deep), and varied little from site to site inside the lagoon. [...] Growth efficiency, determined by correlating the net increase of bacterial biomass, and the net decrease of dissolved organic carbon (DOC) in dilution cultures, was very low (average 6.6 percent). [...]. The turn-over rate of DOC due to bacterial consumption was estimated to be 0.048 per day during the period of study. [About 5 percent of DOC was consumed each day]"
"Planktonic bacteria make important contributions to the bio-geochemical cycles of marine pelagic [water column] ecosystems. In most oceanic environments, bacterial production [growth] represents a significant proportion of primary production [although it is actually "secondary production"], and in the most [low dissolved nutrient] environments, bacterial biomass may even exceed phytoplankton biomass. In coral reef environments, bacterioplankton have been studied mostly in the water column overlying coral reefs, while atoll and island lagoons have received less attention. Atoll and island lagoons may, however, represent large bodies of water where heterotrophic bacterioplankton with low carbon-to-nitrogen ratios relative to the phytoplankton, could be an important contributor to particulate nitrogen [amounts]. Nutrient recycling is essential in coral reef areas [no relying on water changes], often characterized by low concentrations and inputs of new nutrients. Hence, the understanding of bacterioplankton dynamics is essential to studies of carbon and nutrient cycling in coral reef environments."
"Vertical and spatial distributions of bacterioplankton abundance and production were investigated during a two week cruise on the ORSTOM R/V Alis from 18 to 29 May 1994. [...] Free and attached bacterioplankton, production, and dissolved organic carbon were determined in selected samples."
"Bacterioplankton carbon growth yield (CGY) was estimated for the same cultures by correlating DOC consumption with the increase of bacterial biomass."
"DOC concentrations decreased significantly (see figure 4) within the cultures, while bacterial [mass] increased."
"The whole heterotrophic bacterioplankton community (free + attached) had an average specific growth rate of 0.282 per day, and therefore an average generation time of 1/0.282 = 3.6 days."
"Total DOC turnover [elimination] due to bacterioplankton consumption may be estimated from bacterial production (BP) and bacterioplankton carbon growth yield (CGY) determined in the two dilution cultures. Bacterial carbon consumption (BCC) would thus equal BP/CGY. With an average BP of 0.36 ug-at carbon per liter per day, and a CGY of 6.6 percent, BCC equals 0.36/0.066 = 5.5 ug-at carbon per liter per day. Hence, DOC turn-over rate equals 5.5/114 = 0.048 per day, and total DOC turn-over time is 1/0.048 = 21 days [for complete consumption]."
"The two independent determinations allowed the estimation of an average CGY of 6.6 percent. [...] This low CGY value determined in the present study could be interpreted as an index of severe bottom-up limitation of bacterioplankton [i.e., the DOC, which is the food source for the bacteria, is not nearly enough to allow the bacteria to continue growing]."
"The average generation time for the whole bacterioplanktonic community was 3.6 days. This is quite long compared to those estimated over coral reefs, but is in agreement with those determined in atoll lagoons. This long generation time could be explained by a resource limitation of bacteria [not enough DOC to be consumed]."
"Bacterioplankton demand for DOC was estimated to average 5.4 ug-at carbon per liter per day for the period of study. Integrated from the surface to the bottom of the lagoon, the average demand for the 10 stations investigated was 126 mg-at carbon per square meter per day, and was therefore nearly equal to primary production [by algae] during the same period. The net production of bacterial biomass was low compared to particulate primary production (8 percent), but the low estimated growth yield shows that the heterotrophic activity of bacteria was nearly equivalent to primary production. This confirms the importance of bacterioplankton to the remineralization processes in the water column of coral reef lagoons. ["Remineralization" is the conversion of organics, like DOC, into inorganics like nitrate and phosphate]"
"While bacterial growth rates have been frequently reported to be higher inside island or atoll lagoons than in surrounding oceanic waters, lagoon DOC concentrations may be similar, as in this work, or even lower than those of oceanic waters."
"In conclusion, in the Great Astrolabe Reef lagoon, [...] bacterial biomass constituted a significant proportion of POC, and was in the same range as phytoplankton biomass. Heterotrophic demand was of the same order as primary production. The low average growth rate for the bacterioplanktonic community, at an average temperature of about 28 C, and the poor carbon growth yield (6.6 percent), both suggest bacterioplankton to be resource-limited in this lagoon. [...] All these features are consistent with a bottom-up limitation of bacterioplankton."
"[For those interested in a book about DOC, the one to get would be 'Aquatic Ecosystems: Interactivity Of Dissolved Organic Matter', which talks about the types of studies we have covered here, for both fresh and saltwater. It is available as a hardcover book and also as individual PDF chapters:
http://www.sciencedirect.com/science/book/9780122563713 ]"
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Attachments
jc-reef
New member
Originally Posted by capecoral
if you ever get a chance to use a microscope to watch coral polyps (especially SPS) use their chemicals to zap and eat pods, you'll understand. A polyp senses a pod (some polyps actually chase pods), and then it stings the pod with chemicals; it then wraps around it with a sticky net and pulls the pod into the "stomach" of the coral where the pod gets digested over the next couple of hours.
Errr...that video is of a JELLYFISH...not an Acropora. BIG DIFFERENCE my friend...nice try though...:lol2:
Here is the excerpt from the YouTube video you posted....
"NinjaSquid — April 26, 2007 —
Microscopic video footage of jellyfish nematocysts firing. The video was created by the TASRU (Tropical Australian Stinger Research Unit) of James Cook University. The video shows nematocysts along a section of tentacle from Carukia barnesi (Irukandji jellyfish) discharging after artificial stimulation. The image has been filmed through a microscope and is magnified about 400 times."
I agree with cape coral.
http://reefkeeping.com/issues/2002-12/eb/index.php
.....
if you ever get a chance to use a microscope to watch coral polyps (especially SPS) use their chemicals to zap and eat pods, you'll understand. A polyp senses a pod (some polyps actually chase pods), and then it stings the pod with chemicals; it then wraps around it with a sticky net and pulls the pod into the "stomach" of the coral where the pod gets digested over the next couple of hours.
Errr...that video is of a JELLYFISH...not an Acropora. BIG DIFFERENCE my friend...nice try though...:lol2:
Here is the excerpt from the YouTube video you posted....
"NinjaSquid — April 26, 2007 —
Microscopic video footage of jellyfish nematocysts firing. The video was created by the TASRU (Tropical Australian Stinger Research Unit) of James Cook University. The video shows nematocysts along a section of tentacle from Carukia barnesi (Irukandji jellyfish) discharging after artificial stimulation. The image has been filmed through a microscope and is magnified about 400 times."
I agree with cape coral.
http://reefkeeping.com/issues/2002-12/eb/index.php
.....
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Primary Production - Video Introduction
Now we would like to get to the base of how all oceans and lakes work: Primary Production. But before getting into the research papers, we thought it would be easier and more fun for the typical reefer to start with videos. In searching youtube for months for good, basic information for reefers, we decided that the follow videos are by far the most instructive. They are from an oceanography class, and there are a lot of them (even just the ones about Primary Production), so we won't post them all at once. So following will be just the videos from that course that have been selected in a certain order to give the best focus on how the concepts of Primary Production can be used for your tank.
One thing to keep in mind: These videos are about the oceans and lakes, and thus the focus of the Primary Production is on phytoplankton. In your tank, however, the focus is instead on solid algae, because you do not have enough water volume to hold much phytoplankton. So when he says phytoplankton, just think of solid algae instead. This works for almost all the topics in all the videos, starting with this one:
http://www.youtube.com/watch?v=qfMaBeLwiO4
Now we would like to get to the base of how all oceans and lakes work: Primary Production. But before getting into the research papers, we thought it would be easier and more fun for the typical reefer to start with videos. In searching youtube for months for good, basic information for reefers, we decided that the follow videos are by far the most instructive. They are from an oceanography class, and there are a lot of them (even just the ones about Primary Production), so we won't post them all at once. So following will be just the videos from that course that have been selected in a certain order to give the best focus on how the concepts of Primary Production can be used for your tank.
One thing to keep in mind: These videos are about the oceans and lakes, and thus the focus of the Primary Production is on phytoplankton. In your tank, however, the focus is instead on solid algae, because you do not have enough water volume to hold much phytoplankton. So when he says phytoplankton, just think of solid algae instead. This works for almost all the topics in all the videos, starting with this one:
http://www.youtube.com/watch?v=qfMaBeLwiO4
acropora1981
New member
None the less; coral and cnidarian stings are a physical process first, followed by a chemical process sting - not the other way around.
Nice try though.
So I'm still curious. Obviously a ULNS is not optimal for coral growth without somehow additing bacteria or having a bacteria producing source (is this why zeovit is successful?), and otherwise, feeding of corals can be accomplished by several methods but the purpose is not to provide a nutriend rich tank but rather a food-source-rich supply of phyto, via addition of rotifers and the like or shrimp that do the humpty-dumpty on a frequent basis. Obviously too much detritus is detrimental to the health of the tank via too much nutrients creating algae issues.
However, the use of algae in the tank is beneficial, which I can see in the use of macro in the 'fuge. Problem is, which macro to use? I've never had luck with chaeto.
My fuge will contain a sb of approx. 3-4" depth, I will have LR rubble in there and some snails to keep detritus to a minimum. Fuge is fed by the return pump which means post-skimmer water to minimize detritus buildup.
As for coral feeding: I'm thinking a couple pairs of shrimp in the linked frag propagation tank as well as a large fish load, accompanied by a skimmer, but I'd like a suggestion for a bacteria source?
However, the use of algae in the tank is beneficial, which I can see in the use of macro in the 'fuge. Problem is, which macro to use? I've never had luck with chaeto.
My fuge will contain a sb of approx. 3-4" depth, I will have LR rubble in there and some snails to keep detritus to a minimum. Fuge is fed by the return pump which means post-skimmer water to minimize detritus buildup.
As for coral feeding: I'm thinking a couple pairs of shrimp in the linked frag propagation tank as well as a large fish load, accompanied by a skimmer, but I'd like a suggestion for a bacteria source?
mille239
Premium Member
my 2 cents to this thread: The single most beneficial thing I did to my tank to increase coral growth was add a diamond goby; I'm guessing the constant sand sifting leaves a constant supply of suspended particles in the water (but not so much that it affects the water clarity) This is just my hypothesis, but my corals have been thriving since the addition. Just a theory.
dave willmore
New member
Hey folks, I just found this thread. Thanks for the stimulating information. I've thought for a long time of a system to provide constant live food to corals without degrading water quality, and I am building a new tank to do this. May I ask advice on three things to incorporate what you've been saying?
First, it appears that the two biggest enemies of live aquarium plankton are: the 1720 rpm water pump whose fast acceleration effectively kills plankters; and our protein skimmers. I got some 50 watt motors which turn 8" propellers at just 100 rpm, with one thousandth the G force of a 3/4" outlet water pump, and will place the refugium at water level so as not to pump water from the sump. Does this seem the right direction to keep plankton alive long enough to be eaten by corals? Can I replace the protein skimmer with lots of sponges and filter feeders for dissolved organic removal?
Second, keeping millions of zooplankton alive to feed corals require billions of phytoplankton, so a constant microalgae drip seems to be in order and after many failures I learned to culture microalgae. But a phytoplankton drip will raise nitrates and phosphates, so it seems it must be balanced by a refugium large enough that macroalgae harvest equals phytoplankton addition (minus coral and fish growth), right?
Third, turning off the skimmer and adding phytoplankton will require a drastic reduction in feeding, so I'm thinking of recycling the refugium algae back into lots of tangs and pygmy angels. Filamentous algae is their favorite food and if I grow it on 14 screens in the refugium and feed a new (14 day old) algae screen to the fish each day, the need for fish food could perhaps drop low enough for high water quality without skimming. If N and P do rise I guess I could just export more macroalgae.
Am I missing anything? And thanks in advance for welcoming me into such a great conversation.
First, it appears that the two biggest enemies of live aquarium plankton are: the 1720 rpm water pump whose fast acceleration effectively kills plankters; and our protein skimmers. I got some 50 watt motors which turn 8" propellers at just 100 rpm, with one thousandth the G force of a 3/4" outlet water pump, and will place the refugium at water level so as not to pump water from the sump. Does this seem the right direction to keep plankton alive long enough to be eaten by corals? Can I replace the protein skimmer with lots of sponges and filter feeders for dissolved organic removal?
Second, keeping millions of zooplankton alive to feed corals require billions of phytoplankton, so a constant microalgae drip seems to be in order and after many failures I learned to culture microalgae. But a phytoplankton drip will raise nitrates and phosphates, so it seems it must be balanced by a refugium large enough that macroalgae harvest equals phytoplankton addition (minus coral and fish growth), right?
Third, turning off the skimmer and adding phytoplankton will require a drastic reduction in feeding, so I'm thinking of recycling the refugium algae back into lots of tangs and pygmy angels. Filamentous algae is their favorite food and if I grow it on 14 screens in the refugium and feed a new (14 day old) algae screen to the fish each day, the need for fish food could perhaps drop low enough for high water quality without skimming. If N and P do rise I guess I could just export more macroalgae.
Am I missing anything? And thanks in advance for welcoming me into such a great conversation.
dave willmore
New member
you must be very careful to make the distinction between closed systems (such as reef aquaria) and the ocean- they're apples and oranges. this thread has the potential to turn so many reef aquaria into pea soup.[/QUOTE said:
dave willmore
New member
Capecoral,
Your thread prompted me to open a plankton culture manual from my shelf. That book by Hoff and Snell quotes S.A. Poulet (1977) that there is 5 times more detrital biomass in the ocean than phytoplankton biomass and Poulet again in 1983 stating that there is 200 times the detrital biomass than bacterial biomass.
This research ignores that phytoplankton is the primary source of detritus, nor does it indicate coral food preference. Our tanks are slanted to high bacterial biomass but the bacteria is more attached than free floating because pumps selectively kill the floaters. Doesn't it seem to you that slow acceleration pumps are a solution to keeping 24 hour live food for corals? A 50 watt motor moves the same amount of water per hour as a 50 watt powerhead, but an 8" propeller has one thousandth of the kill factor of the 2" prop or impeller because of its slower speed.
Also, the other live food killer is the skimmer, which can be replaced by sponges and shellfish. Sponges are not only high volume water pumps in themselves but they also shed huge amounts of cilia each day which are a great coral food.
Does this seem in line with what you are proposing?
Your thread prompted me to open a plankton culture manual from my shelf. That book by Hoff and Snell quotes S.A. Poulet (1977) that there is 5 times more detrital biomass in the ocean than phytoplankton biomass and Poulet again in 1983 stating that there is 200 times the detrital biomass than bacterial biomass.
This research ignores that phytoplankton is the primary source of detritus, nor does it indicate coral food preference. Our tanks are slanted to high bacterial biomass but the bacteria is more attached than free floating because pumps selectively kill the floaters. Doesn't it seem to you that slow acceleration pumps are a solution to keeping 24 hour live food for corals? A 50 watt motor moves the same amount of water per hour as a 50 watt powerhead, but an 8" propeller has one thousandth of the kill factor of the 2" prop or impeller because of its slower speed.
Also, the other live food killer is the skimmer, which can be replaced by sponges and shellfish. Sponges are not only high volume water pumps in themselves but they also shed huge amounts of cilia each day which are a great coral food.
Does this seem in line with what you are proposing?
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