TbyZ
Well-Known Member
I've posted the following (part) article by Eric Borneman because is says so much & answers so many questions.
From Mything the Point part 3
Myth 15: Concepts about Nitrification, Stocking Orders, and the New Tank
I had owned Nilsen and Fossa's The Modern Coral Reef Aquarium for several years before I noticed one particular photo in that book that is exceptional. It is a nice reef tank, but by no means what most would consider to be a "show winner." However, it is unquestionably a show winner, for it is a reef aquarium that grew solely from live rock. If there is one universal answer to the question, "What does it take to make a successful reef aquarium," the answer is patience.
For those who have not read one of the threads stuck at the top of The Coral Forum, I offer this revised version of that information. A tank begins without populations of anything. Live rock typically forms the initial basis of the biodiversity. Virtually everything is moderated by bacteria and photosynthesis in our tanks. So live rock is the substrate for these microbes and processes, and also has a lot of other life on it. How much depends on a lot of things. Mostly, marine animals and plants don't like to be out of water for a day, much less the many days to sometimes weeks that is common during live rock collection and shipping. So, assuming that existing rock from a tank is not being used, nor the well-treated aquacultured rock, most live rock is either relatively free of anything alive, or has a few stragglers and a whole lot of stuff dying or about to die because it won't survive in aquariums. From the moment it is added to the aquarium, a deficiency has begun that likely worsens over time. Coralline algae, sponges, worms, crustaceans, echinoids, bivalves, algae, chordates, and all manner of other taxa will begin dying, many of which are within the rock and would never be seen. All this occurs without mentioning the algae, cyanobacteria, and bacteria, most of which is dead and will decompose, or which will die and decompose. Life will return to some degree, as we all have experienced, but not until death and more death have occurred. However, this process is where it all begins.
Bacteria grow really fast, and so they are able to grow to levels that are capable of taking up nitrogen within a typical cycling time of a few weeks to a month (or so) to levels where ammonium and nitrite are not measurable by hobby test kits. Most people assume, wrongfully, that the tank is now "cycled." However, the fact that ammonium and nitrite are no longer easily measured does not in any way imply that the tank is truly cycled, mature, stable, or in any way able to easily support life in the form of new additions. I will discuss this more in the passages below.
If one realizes the doubling time of many bacteria, one would know that within a month, there should exist a tank packed full of bacteria with no room for water. That means something is killing or eating bacteria. It should also be realized that if the tank has decomposition happening at a rate high enough to spike ammonia off the scale of a hobby test kit, there is a lot of food for bacteria that consume this material, and far more than will be present when other things stop dying off and decomposing. So, bacterial growth may have caught up with the level of nitrogen being produced, but things are still dying. An aquarist simply "tests zero" for ammonia because there are enough bacteria present to keep up with the nitrogen being released by the dying organisms. It does not mean things are finished decomposing.
Now, if things are decomposing, they are releasing more than ammonia. Guess what dead sponges release? All of their sequestered toxic metabolites. Guess what else? All their natural antibiotic compounds and these will prevent some beneficial microbes from doing very well. The same occurs with the algae, many other invertebrates, the cyanobacteria, the dinoflagellates, and others. Suffice to say that this death and decomposition is going to take a while to complete.
Through the initial periods, there will be a tank packed with some kinds of bacteria, probably not much of others. Eventually, the massive death slows and stops. Now, what happens to all that biomass of bacteria without a food source? They die. So, another cycle of decomposition begins, and this back and forth process will continue for a while until equilibrium is reached. I say equilibrium, but that is a relative term since reproduction and mortality is a constant process in our tanks, as are "mishaps" and the relative size of the pendulum swing will depend on the reproduction and mortality rates, and biomass of the organisms involved. Still, the new swing of dying bacteria also has antibiotics, toxins, and other substances released when they die. But, the die-off is relatively slow, and is relative to the loss of nutrients, and there is already a huge population present. The result to the aquarist is that they never test positive for significant levels of ammonia. "The water tests fine."
Furthermore, denitrification is a slow process. Yet, all these back and forth swings are happening... every time, they get less and less, but they keep happening. Eventually, they slow and stabilize. What's left? A tank with limited denitrification and a whole lot of other stuff in the water. Who comes to the rescue and thrives? The next fastest growing groups... cyanobacteria, single-celled eukaryotic algae, and other protists. Then, they do their little cycle thing. And then come the turf algae. Turfs will soon get mowed down by all the little amphipods that are suddenly springing up because they have a food source and will reproduce rapidly. Perhaps the aquarist has purchased some snails by now, and maybe a fish. All too often, the fish dies, because while it may not have ammonia to contend with, it has water filled with chemicals we can't and don't test for. Beginning aquarists may also have been too frugal with their purchase of important equipment like lights and pumps, and may not have yet figured out the important alkalinity test, so pH and O2 are probably swinging wildly at this point. Tests for phosphate are also usually an afterthought, often purchased only when algal biomass becomes uncontrolled.
As a few more months pass, the algae successions begin, and eventually there exists an algal biomass that handles nitrogen along with the bacteria, and the aquarium keeper has perhaps stopped adding fish for the time being because they keep dying. Maybe during this time they started to visit internet forums, read books, begin learning more, and get the knack of the tank at least a little bit. They have, unfortunately, probably added a smattering of "fix-it-quick" chemicals (that probably didn't help any, either). Also, there are probably two further scenarios; aquarists that are scared to add corals in their "new tank of death" that would actually help with the photosynthesis and nutrient uptake, or aquarists that have packed in corals (most of which aren't tolerant of the "tank of death" conditions). Equally common are aquarists who stock their tank haphazardly without consideration of whether or not the habitat present is suitable, but that is a topic for another article. What may be relevant, however, is the common pattern of stocking corals according to "hardiness" over time. Initially, soft corals of the family Alcyoniidae (leather corals), corallimorpharians (mushrooms) and zoanthids are the first species to be purchased. The rationale for most is that they plan to stock with easy corals and then "move on to stony corals." The problem with the rationale, seemingly logical though it may be, is that success of these type species may make the tank even more incompatible for the success of stony corals because they are typically superior competitors (usually by secreting waterborne chemicals that inhibit or kill the stony corals or by the capability of overgrowing them).
About a year into the experience, the sand bed is productive and has stratified, water quality is relatively stable, and the aquarist has probably bought at least a few more powerheads, understands water quality a bit, some corals, coralline algae and other algae are photosynthesizing well, and the tank is becoming "mature." That's usually when fish stop dying and corals start to live and grow.
Ecologically speaking, this is successional population dynamics. Its normal, and it happens when there is a hurricane or a fire or other disturbance. In nature though, there are pioneer species that are eventually replaced by variably persistent "climax" communities. We usually try and stock tanks immediately with climax species and find it doesn't always work. The preceding passages illustrate what good approximations reef aquariums are of mini-ecosystems. Processes and events tend to happen much faster in tanks, but this should be expected given the number of organisms per unit area. Our "climax community" happens in a couple of years rather than a couple of centuries, but it happens nonetheless.
After all the descriptions above, perhaps the "myth" that is the focus of this article has been forgotten. This section actually covers several myths: the myth reflected by the statement "my tank is cycled" or "my rock is cured," and the myth of the statement "my water tests fine." The truth is that the tank is never cycled, the rock is never cured, and water that "tests fine" may be variably fine in terms of one or a few parameters that may or may not be ultimately important for the survival of the creatures we keep in aquaria. As a supplement to this section, I offer some advice (and "advice" is not something I am overly fond of providing because it tends to be limiting to the viewpoint of the person giving it!). I offer the words from a slide I have given in presentations and am frequently requested to print or email after I have shown that slide to a group. The following is how I would suggest new tanks be initiated:
Potential: Always serious. Mortalities early in the life of an aquarium can usually be prevented. At the worst, these early misconceptions lead to long-term problems with tanks, have medium-term direct effects, and short-term mortality associated with them. Often, prevention and understanding would alleviate the issues, and surely many aquarists leave the hobby because of the many problems that happen early on with new aquarium set-ups.
Distribution: Nearly universal. Being patient with a new tank is almost an exercise in futility that requires restraint. Generally, only those who have kept reef aquariums prior to establishing a new one are likely to take the steps required to ensure the best development and success of new set-ups (and this is still comparatively rare). Ultimately, the development of a tank by the actions of an aquarist who "goes slow" will far outpace those of aquarists who lack the patience and foresight.
Many years down the road, another condition might occur when the system is too mature; this is sometimes called "old tank syndrome." What happens in this situation is that conditions have become somewhat stagnant, or populations that are present are either limited by some resource or are the only species capable of persisting in the relatively non-fluctuating environment. This happens in nature, too. The well-known example of a forest fire reinvigorating the system is true. Equally true examples occur on coral reefs where the intermediate disturbance hypothesis is an experimentally favored explanation of why coral reefs maintain very high diversity; they are stable, but not too stable; require storms, but not catastrophic ones; need predation, but not a giant blanket of crown of thorns starfish; tolerate mortality, but not mass coral bleaching or the near total loss of key herbivores.
http://www.reefkeeping.com/issues/2004-01/eb/
From Mything the Point part 3
Myth 15: Concepts about Nitrification, Stocking Orders, and the New Tank
I had owned Nilsen and Fossa's The Modern Coral Reef Aquarium for several years before I noticed one particular photo in that book that is exceptional. It is a nice reef tank, but by no means what most would consider to be a "show winner." However, it is unquestionably a show winner, for it is a reef aquarium that grew solely from live rock. If there is one universal answer to the question, "What does it take to make a successful reef aquarium," the answer is patience.
For those who have not read one of the threads stuck at the top of The Coral Forum, I offer this revised version of that information. A tank begins without populations of anything. Live rock typically forms the initial basis of the biodiversity. Virtually everything is moderated by bacteria and photosynthesis in our tanks. So live rock is the substrate for these microbes and processes, and also has a lot of other life on it. How much depends on a lot of things. Mostly, marine animals and plants don't like to be out of water for a day, much less the many days to sometimes weeks that is common during live rock collection and shipping. So, assuming that existing rock from a tank is not being used, nor the well-treated aquacultured rock, most live rock is either relatively free of anything alive, or has a few stragglers and a whole lot of stuff dying or about to die because it won't survive in aquariums. From the moment it is added to the aquarium, a deficiency has begun that likely worsens over time. Coralline algae, sponges, worms, crustaceans, echinoids, bivalves, algae, chordates, and all manner of other taxa will begin dying, many of which are within the rock and would never be seen. All this occurs without mentioning the algae, cyanobacteria, and bacteria, most of which is dead and will decompose, or which will die and decompose. Life will return to some degree, as we all have experienced, but not until death and more death have occurred. However, this process is where it all begins.
Bacteria grow really fast, and so they are able to grow to levels that are capable of taking up nitrogen within a typical cycling time of a few weeks to a month (or so) to levels where ammonium and nitrite are not measurable by hobby test kits. Most people assume, wrongfully, that the tank is now "cycled." However, the fact that ammonium and nitrite are no longer easily measured does not in any way imply that the tank is truly cycled, mature, stable, or in any way able to easily support life in the form of new additions. I will discuss this more in the passages below.
If one realizes the doubling time of many bacteria, one would know that within a month, there should exist a tank packed full of bacteria with no room for water. That means something is killing or eating bacteria. It should also be realized that if the tank has decomposition happening at a rate high enough to spike ammonia off the scale of a hobby test kit, there is a lot of food for bacteria that consume this material, and far more than will be present when other things stop dying off and decomposing. So, bacterial growth may have caught up with the level of nitrogen being produced, but things are still dying. An aquarist simply "tests zero" for ammonia because there are enough bacteria present to keep up with the nitrogen being released by the dying organisms. It does not mean things are finished decomposing.
Now, if things are decomposing, they are releasing more than ammonia. Guess what dead sponges release? All of their sequestered toxic metabolites. Guess what else? All their natural antibiotic compounds and these will prevent some beneficial microbes from doing very well. The same occurs with the algae, many other invertebrates, the cyanobacteria, the dinoflagellates, and others. Suffice to say that this death and decomposition is going to take a while to complete.
Through the initial periods, there will be a tank packed with some kinds of bacteria, probably not much of others. Eventually, the massive death slows and stops. Now, what happens to all that biomass of bacteria without a food source? They die. So, another cycle of decomposition begins, and this back and forth process will continue for a while until equilibrium is reached. I say equilibrium, but that is a relative term since reproduction and mortality is a constant process in our tanks, as are "mishaps" and the relative size of the pendulum swing will depend on the reproduction and mortality rates, and biomass of the organisms involved. Still, the new swing of dying bacteria also has antibiotics, toxins, and other substances released when they die. But, the die-off is relatively slow, and is relative to the loss of nutrients, and there is already a huge population present. The result to the aquarist is that they never test positive for significant levels of ammonia. "The water tests fine."
Furthermore, denitrification is a slow process. Yet, all these back and forth swings are happening... every time, they get less and less, but they keep happening. Eventually, they slow and stabilize. What's left? A tank with limited denitrification and a whole lot of other stuff in the water. Who comes to the rescue and thrives? The next fastest growing groups... cyanobacteria, single-celled eukaryotic algae, and other protists. Then, they do their little cycle thing. And then come the turf algae. Turfs will soon get mowed down by all the little amphipods that are suddenly springing up because they have a food source and will reproduce rapidly. Perhaps the aquarist has purchased some snails by now, and maybe a fish. All too often, the fish dies, because while it may not have ammonia to contend with, it has water filled with chemicals we can't and don't test for. Beginning aquarists may also have been too frugal with their purchase of important equipment like lights and pumps, and may not have yet figured out the important alkalinity test, so pH and O2 are probably swinging wildly at this point. Tests for phosphate are also usually an afterthought, often purchased only when algal biomass becomes uncontrolled.
As a few more months pass, the algae successions begin, and eventually there exists an algal biomass that handles nitrogen along with the bacteria, and the aquarium keeper has perhaps stopped adding fish for the time being because they keep dying. Maybe during this time they started to visit internet forums, read books, begin learning more, and get the knack of the tank at least a little bit. They have, unfortunately, probably added a smattering of "fix-it-quick" chemicals (that probably didn't help any, either). Also, there are probably two further scenarios; aquarists that are scared to add corals in their "new tank of death" that would actually help with the photosynthesis and nutrient uptake, or aquarists that have packed in corals (most of which aren't tolerant of the "tank of death" conditions). Equally common are aquarists who stock their tank haphazardly without consideration of whether or not the habitat present is suitable, but that is a topic for another article. What may be relevant, however, is the common pattern of stocking corals according to "hardiness" over time. Initially, soft corals of the family Alcyoniidae (leather corals), corallimorpharians (mushrooms) and zoanthids are the first species to be purchased. The rationale for most is that they plan to stock with easy corals and then "move on to stony corals." The problem with the rationale, seemingly logical though it may be, is that success of these type species may make the tank even more incompatible for the success of stony corals because they are typically superior competitors (usually by secreting waterborne chemicals that inhibit or kill the stony corals or by the capability of overgrowing them).
About a year into the experience, the sand bed is productive and has stratified, water quality is relatively stable, and the aquarist has probably bought at least a few more powerheads, understands water quality a bit, some corals, coralline algae and other algae are photosynthesizing well, and the tank is becoming "mature." That's usually when fish stop dying and corals start to live and grow.
Ecologically speaking, this is successional population dynamics. Its normal, and it happens when there is a hurricane or a fire or other disturbance. In nature though, there are pioneer species that are eventually replaced by variably persistent "climax" communities. We usually try and stock tanks immediately with climax species and find it doesn't always work. The preceding passages illustrate what good approximations reef aquariums are of mini-ecosystems. Processes and events tend to happen much faster in tanks, but this should be expected given the number of organisms per unit area. Our "climax community" happens in a couple of years rather than a couple of centuries, but it happens nonetheless.
After all the descriptions above, perhaps the "myth" that is the focus of this article has been forgotten. This section actually covers several myths: the myth reflected by the statement "my tank is cycled" or "my rock is cured," and the myth of the statement "my water tests fine." The truth is that the tank is never cycled, the rock is never cured, and water that "tests fine" may be variably fine in terms of one or a few parameters that may or may not be ultimately important for the survival of the creatures we keep in aquaria. As a supplement to this section, I offer some advice (and "advice" is not something I am overly fond of providing because it tends to be limiting to the viewpoint of the person giving it!). I offer the words from a slide I have given in presentations and am frequently requested to print or email after I have shown that slide to a group. The following is how I would suggest new tanks be initiated:
Potential: Always serious. Mortalities early in the life of an aquarium can usually be prevented. At the worst, these early misconceptions lead to long-term problems with tanks, have medium-term direct effects, and short-term mortality associated with them. Often, prevention and understanding would alleviate the issues, and surely many aquarists leave the hobby because of the many problems that happen early on with new aquarium set-ups.
Distribution: Nearly universal. Being patient with a new tank is almost an exercise in futility that requires restraint. Generally, only those who have kept reef aquariums prior to establishing a new one are likely to take the steps required to ensure the best development and success of new set-ups (and this is still comparatively rare). Ultimately, the development of a tank by the actions of an aquarist who "goes slow" will far outpace those of aquarists who lack the patience and foresight.
Many years down the road, another condition might occur when the system is too mature; this is sometimes called "old tank syndrome." What happens in this situation is that conditions have become somewhat stagnant, or populations that are present are either limited by some resource or are the only species capable of persisting in the relatively non-fluctuating environment. This happens in nature, too. The well-known example of a forest fire reinvigorating the system is true. Equally true examples occur on coral reefs where the intermediate disturbance hypothesis is an experimentally favored explanation of why coral reefs maintain very high diversity; they are stable, but not too stable; require storms, but not catastrophic ones; need predation, but not a giant blanket of crown of thorns starfish; tolerate mortality, but not mass coral bleaching or the near total loss of key herbivores.
http://www.reefkeeping.com/issues/2004-01/eb/
