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sixty_reefer
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At what organic N and P do you run you tank?
Understanding nutrient limitations
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sixty_reefer
5000 Club Member
I can assure you that it wasn’t the intention although the subject it’s not easy and this was the more simplistic format I could think of to bring it to light to more members.
the understanding on how some limitations may occur in our system could aid in avoiding events in our saltwater systems that may cause nuisance algae’s and bacteria blooms in case the spore or cell are present.
slickreefing
Community Member
There are plenty of finite balances in the aquarium that simply require experience and experimentation. The comprehension of nutrient balance and biological (bacterial) filtration along with mechanical filtration has a fine balance as well. I designed my grow out AIO’s with manual roller mats being the fundamental and sole basis of how the tank would operate with no equipment other than flow and where my bacteria breed and consume waste most effectively. I carbon dose via vinegar or mixtures of Microbacter products or antibiotics as I determine fit based on what I’m currently doing in the tanks when my phosphorus begins to hover and give me climbing numbers between tests. This tells me the bacteria was abundant before but died off to starvation or were consumed by corals completing a full carbon cycle. I only aim to keep below .18PPM phosphate this will happen every now and then but I am typically between .012 and .09 yet if I don’t feed one day I will also bottom out to zero in a span of 36 hours. When I do reach my threshold of .18 I do not feed the corals and sometimes it plummets downward steadily without vinegar or bacteria dosing in less than 48 hours; if I continue feeding it will just sit around that number but I like to know that the available and unavailable nutrients are removed or consumed. It’s hard to explain as this is something we can not test for but you learn the most when you see a coral you grow in a different system and notice how much bigger yours are in individual polyp mass vs a system that doesn’t experience these cycles aggressively pushing the limits of feeding corals.
understanding nutrient limitations
1. Introduction
2. Brief description on the difference between Availability and residual nutrients.
3.Identify nutrient limitations under different filtration methods.
3.1. Heterotrophic bacteria as dominant species effect on nutrients and residual.
3.2. Heterotrophic bacteria and autotrophic split dominance effects on nutrient and residual.
4. Influence of other filtration methods and additives on Nutrients
4.1. Filter sock, poly filter and sponges
4.2. Roller mats
4.3. Macro algae’s
4.4. Carbon Dosing
4.5. Phosphates absorbing Medias
4.6. Phosphates artificial dosing
4.7. Nitrates dosing
4.8. Nitrogen dosing
4.9. Protein skimmer
4.10. Water changes
5. Conclusion
1. Introduction
The following article is a update and a more detailed method to understand some of the information that was posted in a previous thread named “the third Nutrient” where I wrote about the importance of the Nutrient C and a few ways to interpret limitations in Reef Aquaria, I have now realised that although the theory is correct it can’t be applied to all systems. This is due to exist two main types of biological filtration in our hobby, one that is mainly done by heterotrophic bacteria, this will be the most common system in the hobby in my opinion, the second type of biological filtration is the split autotrophic and heterotrophic bacteria dominance this will be more common to folks that still have large amounts of live rock or media in a dark Refugium normally in the sump or in the back of a AIO system this kind of filtration promotes nitrifying and denitrifying autotroph to colonise part of the system and may affect the principal nutrient limitation theory.
One of the goals in this article is to aid other members into understanding how to manage nutrient limitations in aquaria.
2. Brief description on the difference between Availability and residual nutrients.
It is important in my opinion to understand the difference between availability of nutrients and residual nutrients to fully understand the information shared through this thread and for a better perception of how nutrients work.
The availability of nutrients it’s the process from the start of decomposition of organic biomass into organic carbon, nitrogen and phosphorus the nutrients will then be slowly release into the water column and be utilised by many different organisms that habitat our systems including coral and macro algae’s.
The most important organism at controlling nutrients will be bacteria, they are the sole responsible organisms to limit Carbon, Nitrogen and depending on each individual biological filtration Phosphorus.
The above nutrients can’t be tested with home grade test kits at present time unfortunately. What we can test is for residual nitrates and phosphates this will be the nutrients that a system is not using hence why they can increase or decrease during nutritional changes to a particular system.
The charts in the pictures below demonstrates the changes in C N P availability in comparison to the expected changes in residual nutrients during carbon dosing. The chart purpose is to illustrate the difference between availability and residual nutrients, on the first picture chart we can observe how a stable tank would look like wend stable and on the second picture chart we can observe that the increase of the availability of organic carbon would made the residual of nitrates and phosphates decrease.
Picture 1
picture 2
3. Identify nutrient limitations under different filtration methods.
3.1. Heterotrophic bacteria as dominant species effect on nutrients and residual.
How I understand the limitations in C N P Availability of nutrients in a system that is mainly biologically filtered by heterotrophic bacteria.
P limits N and C
That may cause N and C to be in abundance
N limits C
That may cause C to be in abundance
How do I understand abundance in C N P availability of nutrients, abundance means if one of the nutrients is in excess
C abundance
May cause N and P be limited
C and N abundance
May cause P to be limited
Knowing the basics of abundance and limitations we may be able to interpret the limitations and abundance of those nutrients using our residual parameters to have a vague idea of what’s happening at the C N P availability of nutrients level.
Residual of phosphates in connection to P
Phosphates decreasing
It may mean P is starting to be less available
Phosphates at zero
It may Mean that P may not be available in the aquarium
Phosphates increasing
It may Mean P is starting to build up in our aquariums
Residual of Nitrates in connection to N
Nitrates decreasing
It may mean N is starting to be less available
Nitrates at Zero
It may mean that N is not available in the aquarium
Nitrates increasing
It may mean N is starting to build up in our aquariums
3.2. Heterotrophic bacteria and autotrophic split dominance effects on nutrient and residual.
How I understand the limitations in C N P Availability of nutrients in a system that is biologically filtered by heterotrophic and autotrophic bacteria.
Residual nitrates going up
It may mean that there’s not enough media supporting denitrification in the sump/display and the display could be limited by the nutrient C
Residual Nitrates going down
It may mean that there is to much media in the sump/display supporting denitrification or a abundance of the nutrient C in the display.
Residual nitrates stable
The balance is just right between display and sump
Residual phosphates going up
It may mean that most of the nutrient N is being processed by Nitrifying autotrophs in the sump or the display is limited By the nutrient N or C.
Residual phosphates going down
It may mean that there is a abundance of the nutrient N and C in the display.
Residual phosphates stable
The balance is just right between display and sump
4. Influence of other filtration methods and additives on Nutrients
4.1. Filter sock, poly filter and sponges
The above filtration can influence the availability of nutrients and residual nutrients, the way they will influence is due to the contact time with the water column the longer it takes in between changes or cleaning the more nutrients will be available to the overall system.
If a system is used to only have them clean or replaced once a week a change in husbandry like moving from weekly to daily could influence the overhaul stability of the supply of available nutrients to a particular system.
4.2. Roller mats
Rollers are definitely a impressive way to automate mechanical filtration the only disadvantage or advantage in my opinion is how effective they are at removing uneaten food from the water column before they start to break down and be able to release nutrients.
If a particular system is observed to start depleting nutrient sometimes by reducing the speed of the roller you should be able to increase the overall availability of nutrients or increase the speed to lower nutrients.
A change from a filter sock to a roller mat could be one of this situations and I would personally recommend that after the change the roller is set to the lower speed for a few weeks to let the organism in the tank adapt to the new availability of nutrients and slowly increase the speed for the previous reasons.
4.3. Macro algae’s
Macro algae’s are a good way to reduce the residual of Nitrates and Phosphates the only thing that makes them a more complex nutrient export is they’re demand in trace elements and sometimes this can become a issue for continuous growth they may also compete with coral for some of the trace elements.
4.4. Carbon Dosing
Carbon dosing in the form of pellets or the many liquid forms it’s a good way to reduce the the build up of the residual nutrients N and P
4.5. Phosphates absorbing Medias
They ideal to adjust the build up of Residual phosphates without making any large changes to the overall balance of the system
4.6. phosphates artificial dosing
It is a efficient way to increase a target nutrient in a controlled fashion.
4.7. Nitrates dosing
It is a efficient way to increase a Target Residual nutrient in a controlled fashion.
4.8. Nitrogen dosing
Nitrogen dosing it is a effective way to increase the availability of N in a system it will also be a good source of nutrients to aid the growth of bacteria population if desired.
4.9. Protein skimmer
They are a effective way to remove excess organics from the water column before they can break down into available nutrients.
4.10. Water changes
In my opinion water changes are not a effective way to control nutrients, they are efficient in emergencies and in other areas of the hobby like replenish trace elements, regarding nutrient control I believe that they are the last resource to look for.
5. Conclusion
The above information is a easier way to interpret what’s happening in a system at the nutrient level, once identified the type of filtration that a system has and the potential dominant bacteria it can becomes easier to understand what is affecting the nutrition on that individual system for a ease of response from the end user to make more informative adjustments if required, I’ve made a effort to keep everything as simple as possible so that folks can understand the methods regardless of the level of experience.
I may have missed a few things although the basics to understand Nutrition will be present in a way or another in the thread.
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sixty_reefer
5000 Club Member
The availability of organic nutrients Vs inorganic nutrient will always be something hard to manage and quantify, organic nutrients like phosphorus and nitrogen don’t tend to stay around for long in our systems giving coral just a small windows to be able to assimilate those nutrients before they become inorganic.
Aquarists that balance correctly the import of organic and export inorganic nutrients will always have the upper hand in relation to coral growth compared to others that will try and grow coral with just inorganic nutrients.
Nutrients is a mind field and most likely the hardest subject in our hobby as so many variables in filtration, additives and food supplements can affect the overall consumption and depletion.
I may have left out some valuable information out of this article, the principal limitation were determined using the marine detritus molar ratio that is coincidental a similar molar ratio to the composition of sea water and phytoplankton.
I have been studying phytoplankton at the hobby level for almost a decade now and it seems to me that phytoplankton is much more than just food for zooplankton like rotifers and copepods, phytoplankton seems to be the source of life in the ocean and trough the process of demineralization consequentially this algae will be introducing organic nutrients in sea water that can feed bacteria, algaes and several other organisms.
In this video I can observe that same process were the demineralisation process is being made by bacteria and anecdotally as I don’t have the equipment to test, re introducing organic nutrients into the water colum the below picture is of a standard montipora after being in a system that was feed live phytoplankton every 60 minutes for 2.5 years.
one of the aspects that I’ve observed during those two years was the rapid growth in coral and the PE, in some cases like in this montipora digitata the PE was abnormal leading me to believe that phytoplankton can deliver nutrients like carbohydrates, vitamins, proteins and aminos in the most favourable way to inverts and micro organisms.
the videos below is how the sump was inundated by life and macro algae’s grew more healthy.
there is many other ways to achieve similar results went the implementation and management of organic nutrients is well managed, bacteria driven ULNS are good examples.
It seems that the best growth is mostly observed wend a technique that manages import of organic and a good export of pollutants inorganic nutrients is implemented.
Coincidentally the same system that I just showed above thriving in coral and diversity had a turn for the worst once the limitations were ignored. The system eventually become limited in Nitrates and there was a massive lost in diversity.
dinoflagellates established in the system.
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Writing a technical article has strict requirements. When just one of those requirements is missing, the entire article can fall apart like a house of cards. What I have seen of the ideas so far and the feedback from knowledgable folks, a technical article is not appropriate at this stage of development of the idea.
“Pretty hard“ is appropriate in this situation and I applaud those folks for taking the time being very clear about what this article needs, even offering help. This idea is a tantalizing one. It runs afoul of some science but that is not a death sentence for it. This issues just need addressing.
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sixty_reefer
5000 Club Member
As knowledge folks are you referring to the chap that doesn’t know the difference between inorganic phosphates and organic phosphorus?
If you going to be “pretty hard” at list show me that you understand the subject before hand!
Do you understand the subject? As I recall you stayed as a intrigued “observer” during the discussions.
Unless you are going to introduce a valuable contribution here that will disprove the article I don’t see a point to your comment.
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MnFish1
10K Club member
I read the article, and some of the other threads. I am not going to comment/care about the grammar, etc so much. But I would caution you @sixty_reefer that you are taking issues that are extremely complex, oft debated with multiple potential theoretical solutions, and based on your ideas of how 'everything works', simplifying with no real documentation/evidence? Additionally absent IMHO is a discussion about what you're potentially missing/how you might be incorrect. As one example - your graphs show a nice 'picture' - but (unless I misunderstand) - there is no data to show where the pictures come from. Here are some suggestions:
1. Clearly state your theory in the introduction.
2. Provide the data/references that bolster your theory
3. Discuss potential pitfalls of your theory
4. Write a conclusion
I think some kind of structure like this - which to a degree matches the manner in which a scientific article is written would do a lot to make it easier to read.
Thanks for taking the time to write your thoughts!!
1. Clearly state your theory in the introduction.
2. Provide the data/references that bolster your theory
3. Discuss potential pitfalls of your theory
4. Write a conclusion
I think some kind of structure like this - which to a degree matches the manner in which a scientific article is written would do a lot to make it easier to read.
Thanks for taking the time to write your thoughts!!
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sixty_reefer
5000 Club Member
Thank you for the idea, it would help if folks were to point out what part of the theory needs more evidence/data on.
What subject would you suggest that needs more data?
1. heterotrophic bacteria being the dominant specie?
2. the limitations in nutrients that affect the heterotrophic bacteria?
3. the inorganic and organic nutrient connection?
MnFish1
10K Club member
Yes - all 3.
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sixty_reefer
5000 Club Member
Folks prefers videos to read articles this video should be enough to give point 1 some substantial evidence.Yes - all 3.
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