jez
24-02-07, 22:41
Hi
Without getting into vast details of how each system works I will try to give a broad overview of what we want to achieve.
A little history
Up till a few years ago we would if well advised set-up a reef tank using a basic Berlin style system (Live Rock + Skimmer +Lighting) this is still the core of most reef aquariums but in attempts to reduce the nutrient levels closer to those e found in a natural coral reef we have over the years added various additional methods of nutrient export these in no particular order are listed below.
Plenums
An early 90’s fave especially with northern reefers and in the US where many gig’s of internet bandwidth were spent trying to explain how they worked. Although effective when they worked, they often tended to act as a place where nutrients were drawn to but never fully utilised when setup wrong, this has lead to catastrophic failures.
Deep Sand Beds
Not really sure where these started but as plenums proved problematic along came some US aquarists who recommend a 4”- 8” bed of fine sand filled with bacteria and critters the idea to act as an area to culture fauna to act as a nutrient export mechanisms Dr Ron Shimek and Bob Goemans were noted authors on the subject.. Like plenums some worked really well others were ripped out and tons of disused coral sand were added to the average suburban garden.
DSB with Algae Scrubbing
When people found that a DSB alone was not really doing the job that well, they added in additional nutrient export systems in the form of macro algaes. These sat on top of the sand and helped absorb nitrate/phosphate and other assorted nutrients. Many systems today are set-up on this basis and work quite nicely. Other examples have used pulsing xenia and cryptic organisms to help export wastes.
Miracle Mud
Although many people like the system for its simple elegance, of just using a mud spiked with minerals to keep alive an algae that is lit 24/7 alive. It is a system that has a good few people who are hardened advocates but for others it has been less than a bed of roses.
Big Power Skimmers
There is still a trend to use a really good efficient modern skimmer to keep water quality high. For those with lots of fish the biggest skimmer you can dream of is the way forward. The drawbacks are cost and the amount of good things that can be drawn from the water.
In the Ocean
Have a look at any Google search on nitrates in natural seawater and you will find that unless there are problems with run off from agriculture, you will find that without a serious piece of lab equipment, you are not going to be able to even register the natural levels of nitrates. Forget 5ppm being ideal we are talking less than 5ppb. The same applies for phosphates, ammonia and all the other wastes we learn about as reef keepers. Then there are those we don’t, stuff like phenols, fats and lipids and stuff that gets lumped under dissolved organics. Again none of these are usually detectable on a natural coral reef. So now you start to see the size of the problem, in all but the best aquariums this stuff builds up and the net effect is to reduce coral growth and increase the levels of zooanthellae in the corals, making corals look drab brown or faun in colour. This is caused by an explosion of photosynthetic cells on the coral.
Enter low nutrient systems
I have no intention of making this the faq on Zeo or FM systems or to eulogise that this is the only method to achieving a good reef tank. I have been doing this far too long know and have seen good tanks with nothing but a few water changes and a dose of iodine and those powered by all the latest tech crash and burn.
Overview of low nutrient systems
A low nutrient filter system is designed to change your system from one that has largely become algal driven and return it to a bacterial system. What do I mean, the average aquarium when set-up with live rock will quickly become coated with algae’s. This is sometimes called the break in period, but for a lot of aquariums it becomes a fact of life. The ammonia, nitrates, phosphate and all the stuff that is undetectable on a natural coral reef is present and feeds the most outrageous growths of nuisance algae. Even when these systems get half way under control 5-10ppm of nitrate a dash phosphate is enough to keep the algae as the dominant filter method. Many aquariums I have seen look green, there may not be lush growths of hair algae anymore but the rocks have a light green hue, from a build up of nutrients feeding a nice coating of algae cells.
BAK to Bacteria
Until a few years ago we have used algae to drive out the nutrients in our aquariums, as part of a refugium and as undesirable growths on the rocks but what we have forgotten is the power of bacteria. Unlike algae that can only feed on a limited range of foods, there are many types of bacteria that feast on the various wastes in our reef tanks.
The basis of a low nutrient system is this.
To reduce wastes we add a food source for bacteria’s to thrive on, these food sources are designed to target some of the bacteria’s needed to tackle the nutrients we have mentioned above. The next stage is a complex amino acid and vitamin solution. This can combine to provide the right food sources for bacteria’s that need both a carbon source as food and an amino acid. Usually included in the amino complex will be a range of basic stuff that helps the health of coral zooanthellae. Ok so at this point we have a system where the bacteria are breeding and specific nutrients are used as food by the bacteria.
Then we get the odd tank where we have a really poor set of bacteria, simply put the mixed bag of bacteria in our live rock can end up as a simple monoculture. It is at this point that most of the systems offer a probiotic suspended bacteria that can be used to inoculate the system with some good bacteria’s. Yippe Yakault for my aquarium.
Where do the stones and the mysterious pumping come in.
Most of the Zeolites used are a mixed bag of stones designed to absorb ammonia and other elements. This simple process of absorption lowers the available food to the zooanthellae in your corals. Why would I want to do this, well simply put zooanthellae can utilise ammonia from fish feeding and waste as a food source. So trapping the ammonia in the stones via absorption and then consumption, helps stop the explosive cell growth and the subsequent unnatural browning of corals. So as we start to achieve a low nutrient environment where most of the waste is being processed by bacteria, we have to allow the corals to feed. In fact one of the most important effects of creating a low nutrient environment is that it allows the corals to feed naturally, further reducing wastes. Although corals have varied ways of feeding, one that usually they can all use is bacteria. So when we pump our Zeo reactor strings of bacteria are sloughed off into the water and used as a very rich food source for corals. This pumping action also removes dead bacteria cells and revitalises the bacterial bed.
To end
There are many other bottles in the low nutrient aquarists cupboard, these are mostly about feeding or improving the health and colouration of the corals these are used above and beyond the core process mentioned . If you need more info or want to change parts of this text please feel free as it’s a fairly loose and rambling document.
Hope this gives you a bit of an idea
Jez
Without getting into vast details of how each system works I will try to give a broad overview of what we want to achieve.
A little history
Up till a few years ago we would if well advised set-up a reef tank using a basic Berlin style system (Live Rock + Skimmer +Lighting) this is still the core of most reef aquariums but in attempts to reduce the nutrient levels closer to those e found in a natural coral reef we have over the years added various additional methods of nutrient export these in no particular order are listed below.
Plenums
An early 90’s fave especially with northern reefers and in the US where many gig’s of internet bandwidth were spent trying to explain how they worked. Although effective when they worked, they often tended to act as a place where nutrients were drawn to but never fully utilised when setup wrong, this has lead to catastrophic failures.
Deep Sand Beds
Not really sure where these started but as plenums proved problematic along came some US aquarists who recommend a 4”- 8” bed of fine sand filled with bacteria and critters the idea to act as an area to culture fauna to act as a nutrient export mechanisms Dr Ron Shimek and Bob Goemans were noted authors on the subject.. Like plenums some worked really well others were ripped out and tons of disused coral sand were added to the average suburban garden.
DSB with Algae Scrubbing
When people found that a DSB alone was not really doing the job that well, they added in additional nutrient export systems in the form of macro algaes. These sat on top of the sand and helped absorb nitrate/phosphate and other assorted nutrients. Many systems today are set-up on this basis and work quite nicely. Other examples have used pulsing xenia and cryptic organisms to help export wastes.
Miracle Mud
Although many people like the system for its simple elegance, of just using a mud spiked with minerals to keep alive an algae that is lit 24/7 alive. It is a system that has a good few people who are hardened advocates but for others it has been less than a bed of roses.
Big Power Skimmers
There is still a trend to use a really good efficient modern skimmer to keep water quality high. For those with lots of fish the biggest skimmer you can dream of is the way forward. The drawbacks are cost and the amount of good things that can be drawn from the water.
In the Ocean
Have a look at any Google search on nitrates in natural seawater and you will find that unless there are problems with run off from agriculture, you will find that without a serious piece of lab equipment, you are not going to be able to even register the natural levels of nitrates. Forget 5ppm being ideal we are talking less than 5ppb. The same applies for phosphates, ammonia and all the other wastes we learn about as reef keepers. Then there are those we don’t, stuff like phenols, fats and lipids and stuff that gets lumped under dissolved organics. Again none of these are usually detectable on a natural coral reef. So now you start to see the size of the problem, in all but the best aquariums this stuff builds up and the net effect is to reduce coral growth and increase the levels of zooanthellae in the corals, making corals look drab brown or faun in colour. This is caused by an explosion of photosynthetic cells on the coral.
Enter low nutrient systems
I have no intention of making this the faq on Zeo or FM systems or to eulogise that this is the only method to achieving a good reef tank. I have been doing this far too long know and have seen good tanks with nothing but a few water changes and a dose of iodine and those powered by all the latest tech crash and burn.
Overview of low nutrient systems
A low nutrient filter system is designed to change your system from one that has largely become algal driven and return it to a bacterial system. What do I mean, the average aquarium when set-up with live rock will quickly become coated with algae’s. This is sometimes called the break in period, but for a lot of aquariums it becomes a fact of life. The ammonia, nitrates, phosphate and all the stuff that is undetectable on a natural coral reef is present and feeds the most outrageous growths of nuisance algae. Even when these systems get half way under control 5-10ppm of nitrate a dash phosphate is enough to keep the algae as the dominant filter method. Many aquariums I have seen look green, there may not be lush growths of hair algae anymore but the rocks have a light green hue, from a build up of nutrients feeding a nice coating of algae cells.
BAK to Bacteria
Until a few years ago we have used algae to drive out the nutrients in our aquariums, as part of a refugium and as undesirable growths on the rocks but what we have forgotten is the power of bacteria. Unlike algae that can only feed on a limited range of foods, there are many types of bacteria that feast on the various wastes in our reef tanks.
The basis of a low nutrient system is this.
To reduce wastes we add a food source for bacteria’s to thrive on, these food sources are designed to target some of the bacteria’s needed to tackle the nutrients we have mentioned above. The next stage is a complex amino acid and vitamin solution. This can combine to provide the right food sources for bacteria’s that need both a carbon source as food and an amino acid. Usually included in the amino complex will be a range of basic stuff that helps the health of coral zooanthellae. Ok so at this point we have a system where the bacteria are breeding and specific nutrients are used as food by the bacteria.
Then we get the odd tank where we have a really poor set of bacteria, simply put the mixed bag of bacteria in our live rock can end up as a simple monoculture. It is at this point that most of the systems offer a probiotic suspended bacteria that can be used to inoculate the system with some good bacteria’s. Yippe Yakault for my aquarium.
Where do the stones and the mysterious pumping come in.
Most of the Zeolites used are a mixed bag of stones designed to absorb ammonia and other elements. This simple process of absorption lowers the available food to the zooanthellae in your corals. Why would I want to do this, well simply put zooanthellae can utilise ammonia from fish feeding and waste as a food source. So trapping the ammonia in the stones via absorption and then consumption, helps stop the explosive cell growth and the subsequent unnatural browning of corals. So as we start to achieve a low nutrient environment where most of the waste is being processed by bacteria, we have to allow the corals to feed. In fact one of the most important effects of creating a low nutrient environment is that it allows the corals to feed naturally, further reducing wastes. Although corals have varied ways of feeding, one that usually they can all use is bacteria. So when we pump our Zeo reactor strings of bacteria are sloughed off into the water and used as a very rich food source for corals. This pumping action also removes dead bacteria cells and revitalises the bacterial bed.
To end
There are many other bottles in the low nutrient aquarists cupboard, these are mostly about feeding or improving the health and colouration of the corals these are used above and beyond the core process mentioned . If you need more info or want to change parts of this text please feel free as it’s a fairly loose and rambling document.
Hope this gives you a bit of an idea
Jez