The following article explains to new Reef Tank members a look at the process of cycling of a new tank or the recycling of an older system. It also describes the nitrogen process and how it works, what to look for after the "cycle" has completed, and more importantly for us reefers when it is safe to add livestock, corals, and/or invertebrates.
In this article:
• How to start the cycle
• How the Nitrogen process works
• What to looking after the cycle occurs
• When can I add livestock, corals, etc.
• The Moron Cycle
How to start the cycle
When one cycles ones tank they are basically looking to establish a population of a variety of bacteria types. These bacteria will aid in the process of reducing both harmful and unwanted nutrients with in the tank and system. They also will provide for a variety of other effects such as reducing metals, buffering calcium and alkalinity and a few more things we can go over in this write up.
Assuming the tank is set up and you have everything in place including water you can start your cycle with the simple addition of a piece of reducible material such as a piece of shrimp or similar, even fresh Live rock will have enough dead and decaying material to start the cycle on its own. When you use Live Sand or Live Rock present in your new setup you actually have all the bacteria strains that you need, just not in a large enough population in relation to your tank size.
A Nitrospira cell
The process begins, when an animal/plant dies or you have an amount of dead material in your tank, bacteria will begin to breakdown the proteins with in the dead material this process is called Mineralization. These Heterotrophic microbes will basically use the organic substrate as their source of carbon (for growth) and Ammonia (NH3) is their byproduct. You can follow this process in your new or redone system by testing your water for ammonia, using one of many test kits available on the market. You should see a steady rise in the level of ammonia in your tank, then finally peeking out and it slow decline to close to zero.
Although some bacteria are free swimming, most bacteria will settle on and in the sub-straights with in the tanks. They often will create bacterial highways for the transfer of both nutrient in and end product out. The highways are made up of variety products of which the sum is called biofilm; this biofilm can also create its own environments. With this in mind bacteria not restricted to particular areas or sub-straights.
How the Nitrogen process works
Once this process of ammonification (as mentioned above) begins it will prompt another strain of bacteria to become more dominate. What prompts this population increase is the presence of ammonia itself. Nitrifying bacteria use the ammonia as a source of energy (to aid in growth and so on) and thus fix that ammonia to their matrix (themselves). These Nitrifying bacteria are Aerobic and thus require oxygen for respiration, Ammonia for their inorganic compound energy source and then carbon dioxide as their source of carbon. So basically they derive their energy source by the conversion of Ammonia to Nitrite and then from nitrite to nitrate. Again one can follow these processes by simply tested for both nitrite and nitrate. With the increase of nitrite and then nitrate we can determine (like we did with the ammonia) that these types of bacteria have increase in population (thus the increase in their byproduct) to meet the food available if the tank, as we see these levels drop we can then also assume the populations have decreased to a point where there is enough bacteria present to handle the current bio load.
The process of converting ammonia to nitrite and then Nitrite to nitrate are basically processes that take place is in an aerobic (oxygenated) environment but then next process happens in an area that is devoid of oxygen, we call this area Anaerobic. So you will find the bacteria that take up this next process to be located within your Live Rock, Sand substrate, or within the biofilm created by the bacteria themselves. These bacteria basically use organic carbon, hydrogen as an electron donator and then nitrate as an electron acceptor. The donor gets oxidized and the nitrate is reduced to dinitrogen gas, but in our tanks if there is the presence of ammonia it will inhibit the first enzyme used in the process so it is then basically turned back into ammonium and recycled.
Where D.O. = Dissolved Organics, NH3 = Ammonia, NO2 = Nitrite, NO3 = Nitrate, NH4 = Ammonium, SO4 = Sulfate, H2S = Hydrogen Sulfide. Oxic= Oxygenated, Hypoxic = Reduced oxygen, Anoxic = Depleted of oxygen, Anaerobic = Devoid of oxygen.
* Note this same process occurs in your Live Rock.
What to looking after the cycle occurs
Ok so that is a basic explanation of what goes on when cycling a new tank bacteria wise. But we must understand that our main goal is to create a stable environment in our system, so let's dig a little bit deeper. Every action we do to our system has a reaction, so we must keep this in mind as we go through the life of a reef tank. As we have seen above the addition of a food source (the dead piece of shrimp and fresh LR) has created a reaction of bacteria population growth that has risen to meet the level of food available to them. So what happens when the bacteria reduce this massive amount of extra food we gave to them and it's no longer available (as they reduced it)?? Well that is where natures next most Johnny on the spot comes into play, and that is Algae. As the bloom of bacteria dies off as their food source has been reduced and the current level can't sustain such a level, they release whatever nutrients they absorbed back into the water. Whatever algae spores exist in the tank (and there are always spores of many types on LR) they will begin to absorb and use the released nutrients to begin their population increase. You can expect to see large algae blooms of a variety of types and also the appearance of cyanobacteria (a type of algae/bacteria blend critter). They will continue to increase until they have used up all the available nutrients that are in the tank. As with the bacteria they will use up all available nutrients and their population will rise, what we call a bloom, but just like the bacteria when they use up the source they will also begin to die off and then bacteria will begin its cycle of blooming. This is a very natural process that is required in order to find the tanks balance. You have to look at it like a pendulum, the tank will swing from bacterial blooms to algae blooms, each getting less and less until the tank eventually finds it balance where there are just enough nutrients to support the bacteria and starve out the algae (or at least the nuisance algae).
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At the point where one can see that the algae is about to bloom, as in you can see it start to form on the various surfaces of the tank. I find this is a good point to do a massive water change, what I suggest to people is to take out as much water as you can (without exposing the LR) and while blowing the rock and sand surface (you do this to remove dead and decaying material). This will allow you to remove allot of the available material in the water column and detritus one the rock and sand. This will make that pendulum swing a little less and thus a shorter period.
When can I add livestock, corals, etc.
So when can you add critters??? Once the bacteria cycle has completed and you have followed it with testing you should see no measureable levels of ammonia, nitrite and very low levels of nitrates. So this is the point where you can add some critters to your system (prior to algae cycle if you wish), so some fish that tend to be hardy, snails, worms and so on (make sure you research how hardy the critters are). I prefer folks to stay away from corals at this point because the tank is still pretty unstable, nutrient wise and a good algae bloom can smother a coral pretty quick, but if you feel you absolutely have to stick to some of the very hardy soft corals like leathers and similar.
The Moron Cycle
So now you are in the zone of looking for complete balance, no big swings in nutrients, temp, pH, or any of the elements that make up the salt water itself. Look at it like a Zen type of thing. Now this brings us to one of the final types of cycle that all reefers go through (some for years and years). I like to call this cycle the moron cycle. The moron cycle is when the reefer goes through a period of perpetual tinkering. The need to change heaters, add or change a skimmer, lighting upgrades and all the other things we do that has an effect on the nutrients and chemistry in the tank. Although this cycle sometimes never ends its best to see that your system has a gone through a period of time (I suggest at least 6 months) where all the parameters stay flat line. So no big swings in pH, temp, nitrates, calcium, mag, alk and so on. At this point (as long as you have the proper lighting and such) you should be able to jump into the more difficult critters to keep, such as fish harder corals and even sps.
In this article:
• How to start the cycle
• How the Nitrogen process works
• What to looking after the cycle occurs
• When can I add livestock, corals, etc.
• The Moron Cycle
How to start the cycle
When one cycles ones tank they are basically looking to establish a population of a variety of bacteria types. These bacteria will aid in the process of reducing both harmful and unwanted nutrients with in the tank and system. They also will provide for a variety of other effects such as reducing metals, buffering calcium and alkalinity and a few more things we can go over in this write up.
Assuming the tank is set up and you have everything in place including water you can start your cycle with the simple addition of a piece of reducible material such as a piece of shrimp or similar, even fresh Live rock will have enough dead and decaying material to start the cycle on its own. When you use Live Sand or Live Rock present in your new setup you actually have all the bacteria strains that you need, just not in a large enough population in relation to your tank size.
The process begins, when an animal/plant dies or you have an amount of dead material in your tank, bacteria will begin to breakdown the proteins with in the dead material this process is called Mineralization. These Heterotrophic microbes will basically use the organic substrate as their source of carbon (for growth) and Ammonia (NH3) is their byproduct. You can follow this process in your new or redone system by testing your water for ammonia, using one of many test kits available on the market. You should see a steady rise in the level of ammonia in your tank, then finally peeking out and it slow decline to close to zero.
Although some bacteria are free swimming, most bacteria will settle on and in the sub-straights with in the tanks. They often will create bacterial highways for the transfer of both nutrient in and end product out. The highways are made up of variety products of which the sum is called biofilm; this biofilm can also create its own environments. With this in mind bacteria not restricted to particular areas or sub-straights.
How the Nitrogen process works
Once this process of ammonification (as mentioned above) begins it will prompt another strain of bacteria to become more dominate. What prompts this population increase is the presence of ammonia itself. Nitrifying bacteria use the ammonia as a source of energy (to aid in growth and so on) and thus fix that ammonia to their matrix (themselves). These Nitrifying bacteria are Aerobic and thus require oxygen for respiration, Ammonia for their inorganic compound energy source and then carbon dioxide as their source of carbon. So basically they derive their energy source by the conversion of Ammonia to Nitrite and then from nitrite to nitrate. Again one can follow these processes by simply tested for both nitrite and nitrate. With the increase of nitrite and then nitrate we can determine (like we did with the ammonia) that these types of bacteria have increase in population (thus the increase in their byproduct) to meet the food available if the tank, as we see these levels drop we can then also assume the populations have decreased to a point where there is enough bacteria present to handle the current bio load.
The process of converting ammonia to nitrite and then Nitrite to nitrate are basically processes that take place is in an aerobic (oxygenated) environment but then next process happens in an area that is devoid of oxygen, we call this area Anaerobic. So you will find the bacteria that take up this next process to be located within your Live Rock, Sand substrate, or within the biofilm created by the bacteria themselves. These bacteria basically use organic carbon, hydrogen as an electron donator and then nitrate as an electron acceptor. The donor gets oxidized and the nitrate is reduced to dinitrogen gas, but in our tanks if there is the presence of ammonia it will inhibit the first enzyme used in the process so it is then basically turned back into ammonium and recycled.
* Note this same process occurs in your Live Rock.
What to looking after the cycle occurs
Ok so that is a basic explanation of what goes on when cycling a new tank bacteria wise. But we must understand that our main goal is to create a stable environment in our system, so let's dig a little bit deeper. Every action we do to our system has a reaction, so we must keep this in mind as we go through the life of a reef tank. As we have seen above the addition of a food source (the dead piece of shrimp and fresh LR) has created a reaction of bacteria population growth that has risen to meet the level of food available to them. So what happens when the bacteria reduce this massive amount of extra food we gave to them and it's no longer available (as they reduced it)?? Well that is where natures next most Johnny on the spot comes into play, and that is Algae. As the bloom of bacteria dies off as their food source has been reduced and the current level can't sustain such a level, they release whatever nutrients they absorbed back into the water. Whatever algae spores exist in the tank (and there are always spores of many types on LR) they will begin to absorb and use the released nutrients to begin their population increase. You can expect to see large algae blooms of a variety of types and also the appearance of cyanobacteria (a type of algae/bacteria blend critter). They will continue to increase until they have used up all the available nutrients that are in the tank. As with the bacteria they will use up all available nutrients and their population will rise, what we call a bloom, but just like the bacteria when they use up the source they will also begin to die off and then bacteria will begin its cycle of blooming. This is a very natural process that is required in order to find the tanks balance. You have to look at it like a pendulum, the tank will swing from bacterial blooms to algae blooms, each getting less and less until the tank eventually finds it balance where there are just enough nutrients to support the bacteria and starve out the algae (or at least the nuisance algae).
"]
At the point where one can see that the algae is about to bloom, as in you can see it start to form on the various surfaces of the tank. I find this is a good point to do a massive water change, what I suggest to people is to take out as much water as you can (without exposing the LR) and while blowing the rock and sand surface (you do this to remove dead and decaying material). This will allow you to remove allot of the available material in the water column and detritus one the rock and sand. This will make that pendulum swing a little less and thus a shorter period.
When can I add livestock, corals, etc.
So when can you add critters??? Once the bacteria cycle has completed and you have followed it with testing you should see no measureable levels of ammonia, nitrite and very low levels of nitrates. So this is the point where you can add some critters to your system (prior to algae cycle if you wish), so some fish that tend to be hardy, snails, worms and so on (make sure you research how hardy the critters are). I prefer folks to stay away from corals at this point because the tank is still pretty unstable, nutrient wise and a good algae bloom can smother a coral pretty quick, but if you feel you absolutely have to stick to some of the very hardy soft corals like leathers and similar.
The Moron Cycle
So now you are in the zone of looking for complete balance, no big swings in nutrients, temp, pH, or any of the elements that make up the salt water itself. Look at it like a Zen type of thing. Now this brings us to one of the final types of cycle that all reefers go through (some for years and years). I like to call this cycle the moron cycle. The moron cycle is when the reefer goes through a period of perpetual tinkering. The need to change heaters, add or change a skimmer, lighting upgrades and all the other things we do that has an effect on the nutrients and chemistry in the tank. Although this cycle sometimes never ends its best to see that your system has a gone through a period of time (I suggest at least 6 months) where all the parameters stay flat line. So no big swings in pH, temp, nitrates, calcium, mag, alk and so on. At this point (as long as you have the proper lighting and such) you should be able to jump into the more difficult critters to keep, such as fish harder corals and even sps.
