Acropolis

[JiaEn]

11 months in..  

[JiaEn]

Dubious Food

Yup. Feeding dubious looking brown liquid to precious reef tank is....  not for the faint hearted. 

Understand the science behind it gives me some confidence. But it's one thing to talk about science, it's another to translate the confidence into action. 

Never try, never know.  The feeding response is quite good. So... See how it goes. 

[JiaEn]

Dino and Cyano

Finger crossed,  I don't have an outbreak now. However I do have several encounters with out of control dino or cyano bloom,  and had overcome them successfully. I would like to share my thoughts,  and debunk some myths about cyanobacteria and dinoflagellate. 

 

1. My Tank Don't Have Cyano/Dino

Unfortunately,  or fortunately,  a population of cyano, and dino,  are always there in our aquarium. The number maybe very low,  and invisible to our eyes,  but they are there. As certain as their are bacteria in your biofilters and rocks,  the cyano and dino are there on the rocks,  sand bed,  and glass. The only reason stopping them from growing out of control is the rest of the bacteria, algae and corals, competing (successfuly) against them, keeping them in check. 

 

2. Cyano and Dino Appears when Nitrate and Phosphate is Zero

This is one of the most repeated statements about cyano and dino. However,  I think this does not represent the full picture. 

Cyano and Dino are living organisms which requires nitrogen and phosphorus elements to grow and reproduce, just like any other organism does. So if one start to believe that the lack of nutrients leads to proliferation of these "pests", one is mistaken. While cyano is able to fix nitrogen from dissolved gas,  all of them requires phosphorus from their enviroment. Therefore. If there is no phosphus available,  neither cyano or dino can strive. 

Then how do we reconcile the fact that many reefers observe cyano or dino outbreak,  when their nitrate and phosphate levels are zero? Look back at my previous paragraph,  these organism needs nitrogen and phosphorus,  but not necessarily in the form of nitrate and  phosphate. Our test kits cannot detect other forms of nitrogen,  nor organic phosphates. Therefore,  conceivably the aquarium can at the same time be NP rich,  yet detects 0 on the different test kits. 

What can possibly lead to this situation?  One of the possibility lies in disruption of food chain, where heterotrophic bacteria population is suppressed.  In the absence of these,  organic compounds remain in the aquarium, the inorganic salts remain low, and many nutrients are available, and preferred by cyano and dino. 

 

3. Medication

Many reefers recieve the advise to medicate when faced with blooms. Many discussions have taken place regarding both the efficacy and safety of various treatments. While I believe many treatments can effectively and safely suppress the cyano or even dino, I am against medicating against these organisms. 

The reason is simple. These organisms thrives because of available nutrients in the aquarium. When they grow,  they actually takes up these nutrients and fix them in their bio mass. If we were to kill them through medication, these excess nutrients are onces again released into the water column. It may solve the symptoms of algae bloom,  but it does little to address the source of the problem. 

I advocate physical removal of the offensive algae through siphoning, into a filter sock in the sump. This way,  we have the confidence that whatever offending nutrients is removed from the system for good. 

[dtdream]

2 hours ago, JiaEn said:

. Cyano and Dino Appears when Nitrate and Phosphate is Zero

This is one of the most repeated statements about cyano and dino. However,  I think this does not represent the full picture. 

Cyano and Dino are living organisms which requires nitrogen and phosphorus elements to grow and reproduce, just like any other organism does. So if one start to believe that the lack of nutrients leads to proliferation of these "pests", one is mistaken. While cyano is able to fix nitrogen from dissolved gas,  all of them requires phosphorus from their enviroment. Therefore. If there is no phosphus available,  neither cyano or dino can strive. 

Then how do we reconcile the fact that many reefers observe cyano or dino outbreak,  when their nitrate and phosphate levels are zero? Look back at my previous paragraph,  these organism needs nitrogen and phosphorus,  but not necessarily in the form of nitrate and  phosphate. Our test kits cannot detect other forms of nitrogen,  nor organic phosphates. Therefore,  conceivably the aquarium can at the same time be NP rich,  yet detects 0 on the different test kits. 

What can possibly lead to this situation?  One of the possibility lies in disruption of food chain, where heterotrophic bacteria population is suppressed.  In the absence of these,  organic compounds remain in the aquarium, the inorganic salts remain low, and many nutrients are available, and preferred by cyano and dino. 

This is interesting comment. It does make sense that correlation doesn't necessarily mean causation. Do you have any further reading resources that you can point me to on this topic (Cyano and especially Dinos in nitrate/phosphate zero environments)? e.g. books or weblinks would be great.

[JiaEn]

44 minutes ago, dtdream said:

This is interesting comment. It does make sense that correlation doesn't necessarily mean causation. Do you have any further reading resources that you can point me to on this topic (Cyano and especially Dinos in nitrate/phosphate zero environments)? e.g. books or weblinks would be great.

Perhaps you can take a look at these

https://www.sciencedirect.com/science/article/abs/pii/S0025326X05001062

https://www.sciencedirect.com/science/article/abs/pii/S1568988317301014

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3849724/

It's important to note that nitrate and phosphate are not the only available (or even preferred)  type of N and P in the aquarium. 

Also,  even if we test zero using our test kits,  it merely means it's below the limit of detection of the kit.

[JiaEn]

Flow Problem 

As the acropora grow,  the flow starts to slow down significantly. The open channel I relied on to generate entrainment flow is no longer sufficient. 

The thing about coral induced flow change is that they do so slowly. As such,  it often happen without the aquarist noticing,  untill  coral starts to be unhappy. 

I noticed my hyacinthus (red circle) starts to have less and less polyp extension,  and started to see more detritus accumulated within it's branchlets. Certainly a sign of lack of flow. 

 

Solutions

I have basically 3 options to rectify this. 

1. Add an additional wavemaker on the left side, and hoping the added flow can pentrate the new growth

2. Install a gyre style flow on the opposite (right) side,  to have a wide stream pushing to the left

3. Install a wavemaker on the right side,  to target the weak zone directly. 

I end up with option 3. Installed a small jebao wavemaker (blue)  and pushes water along the arrow.  It's in the shade, so fairly invisible from the front. The targeted flow show be able to provide for a lot more growth on the main structure. 

 

Problem of the Solution 

The new wavemaker produces two new challenges. Firstly,  the enhanced flow poses some challenges for the clams. Their mantles may over flex and become stressed. I moved some corals around to divert the flow over it. 

Another challenge is that now I have to have a ugly magnet on the side viewing panel.  I will do something about it soon. 

 

[JiaEn]

Dealing with the Sand 

The sand bed has been a pain to keep clean.  Manual blasting with turkey baster works well,  but it's tough and a bit risky to clean around the clams. My lazy solution? Surround the clams with lps so that I don't need to clean those area anymore. I know this is not the ideal situation,  but oh well,  less work is better I guess. 

 

Let the Time be on Our Side

At the end of the day. It takes time for a coral to establish itself, and show its full potential. So keeping the system stable for as long as possible is the key to good growth and good color. 

Some of my acro are recovering and gaining nice color. While some others are still work in progress. 

Good yellow tone on the pikachu acro. 

Strawberry Shortcake with blue tips, quite a unusual look. 

Rockstar acropora.  This was a much abused, miserable frag from a colony which slowly declined to oblivion. I cut off this frag and glue it without much expectations. It looked exactly miserable for 6 months. Now,  the yellow highlights started to return,  slowly. 

This is a super pale tenuis. Quite a mystery this is. The colony is placed at the bottom 1//4 of the tank,  so the amount of light shouldn't be overwhelming. However,  the light side of the colony is snowy pale with light fluorescence color. Fortunately the polyp extension is still good. So I suppose they should be safe nutritionally. 

 

Again,  only time will tell. 

[Harlequinmania]

On 8/7/2021 at 8:15 PM, JiaEn said:

Dino and Cyano

Finger crossed,  I don't have an outbreak now. However I do have several encounters with out of control dino or cyano bloom,  and had overcome them successfully. I would like to share my thoughts,  and debunk some myths about cyanobacteria and dinoflagellate. 

 

1. My Tank Don't Have Cyano/Dino

Unfortunately,  or fortunately,  a population of cyano, and dino,  are always there in our aquarium. The number maybe very low,  and invisible to our eyes,  but they are there. As certain as their are bacteria in your biofilters and rocks,  the cyano and dino are there on the rocks,  sand bed,  and glass. The only reason stopping them from growing out of control is the rest of the bacteria, algae and corals, competing (successfuly) against them, keeping them in check. 

 

2. Cyano and Dino Appears when Nitrate and Phosphate is Zero

This is one of the most repeated statements about cyano and dino. However,  I think this does not represent the full picture. 

Cyano and Dino are living organisms which requires nitrogen and phosphorus elements to grow and reproduce, just like any other organism does. So if one start to believe that the lack of nutrients leads to proliferation of these "pests", one is mistaken. While cyano is able to fix nitrogen from dissolved gas,  all of them requires phosphorus from their enviroment. Therefore. If there is no phosphus available,  neither cyano or dino can strive. 

Then how do we reconcile the fact that many reefers observe cyano or dino outbreak,  when their nitrate and phosphate levels are zero? Look back at my previous paragraph,  these organism needs nitrogen and phosphorus,  but not necessarily in the form of nitrate and  phosphate. Our test kits cannot detect other forms of nitrogen,  nor organic phosphates. Therefore,  conceivably the aquarium can at the same time be NP rich,  yet detects 0 on the different test kits. 

What can possibly lead to this situation?  One of the possibility lies in disruption of food chain, where heterotrophic bacteria population is suppressed.  In the absence of these,  organic compounds remain in the aquarium, the inorganic salts remain low, and many nutrients are available, and preferred by cyano and dino. 

 

3. Medication

Many reefers recieve the advise to medicate when faced with blooms. Many discussions have taken place regarding both the efficacy and safety of various treatments. While I believe many treatments can effectively and safely suppress the cyano or even dino, I am against medicating against these organisms. 

The reason is simple. These organisms thrives because of available nutrients in the aquarium. When they grow,  they actually takes up these nutrients and fix them in their bio mass. If we were to kill them through medication, these excess nutrients are onces again released into the water column. It may solve the symptoms of algae bloom,  but it does little to address the source of the problem. 

I advocate physical removal of the offensive algae through siphoning, into a filter sock in the sump. This way,  we have the confidence that whatever offending nutrients is removed from the system for good. 

What is you though that adding nutrient into the tank ( i.e; feeding more ) ect that would helps solve the cyno and dino issue ? 

i remember one of the very old LFS owner sharing with me that one of the natural method of solving cyno issue that he use is " stirring the sand bed" slightly which result in more bacteria reaction in the system to help solve cyno / dino issue.

[JiaEn]

1 minute ago, he said:

What is you though that adding nutrient into the tank ( i.e; feeding more ) ect that would helps solve the cyno and dino issue ? 

i remember one of the very old LFS owner sharing with me that one of the natural method of solving cyno issue that he use is " stirring the sand bed" slightly which result in more bacteria reaction in the system to help solve cyno / dino issue.

At this stage, I believe cyano/dino blooms not in the absence of nutrients but in the presence of nutrients not easily used by it's competitors (other algae, bacteria,  coral etc). So while adding nutrients may help those competitors and potentially allow them to overwhelm cyano/dino, it does not directly address the surplus of dino/cyano feeding nutrients.  Not to mention, partial breakdown of the food we feed can produce nutrients ideal for cyano/dino growth. 

That's why I feel promoting heterotrophic bacteria is very effective in preventing cyano/dino outbreak. These bacteria seems to consume same family of nutrients - dissolved organic compounds.  If the aquarium does hot have competent population of heterotrphic bacteria, the weakness in the food web will always be exploited by cyano/dino.  

 

As for stirring of the sand bed....  That's literally and figuratively a can of worms. I'm all for cleaning sand bed as regular maintenance, but stirring it when there is an outbreak,  imo,  is too much of a gamble. In any case,  if the goal is to aggresively breakdown organics to reduce nutrients for nuisance algae, I find the combination of zeozym, coral snow and activated carbon extremely effective. 

 

[equiox]

Zeovit reefer spotted! 

[JiaEn]

3 hours ago, equiox said:

Zeovit reefer spotted! 

Yay! 

But not full zeovit. It's a hybrid of zeovit and zeolight. 

[JiaEn]

Food for Thought

Imagine you are a colony of super sun coral,  sitting in the shade along some reef slope or a cave. Since you don't have any zooxanthelle, you have to actively capture food from the surrounding to stay alive. So what kind of food would you likely eat? 

Looking at the size of the mouth of these dendrophyllia,  it's only natural to think that probably small pellet sized food is what they eat naturally, because they kind of fit right into the mount of the coral. Yet as I look closely at these animals, I realised that something doesn't add up. 

For a wild colony of dendrophyllia, how likely is it for each individual polyps to have access to large and slow food, on a regular basis? 

Nobody is target feeding these corals 365 days a year. Therefore I felt it is very unlikely that these NPS would demand large particles of food.

 

Pico and Nanoplankton

The ocean is awash with different planktons,  but when it comes to size and availability, there is a lot of difference.  Turns out that the smaller the size of the plankton,  the more abundant they are(Darcy,2014). 

It is then much more sensible for all these sessile predators to go after the most abundant of preys - pico and nanoplankton. These consists of bacteioplanktons,  dinoflagellate, diatoms and a variety of micro algae. The size of these particles ranges from 0.2-20 um (while in contrast, reef roid has a particle size of 150-300 um).

Having looked around for some studies to confirm or disapprove my guess,  I came across several papers. In one study(Leal, 2014),  the author used molecular markers to test if coral species takes up microalgae.  In another (Houlbrèque, 2004) the authors examine the importance of planktonic prey for corals.  They were able to show that the corals do obtain significant organic carbon and proteins from these planktonic food. 

 

Implications? 

Finding the correct food source for corals (regardless of zooxanthelle) is an area for progress to be made. No doubt the commercially available coral supplements are getting better. But could there be some "holy grail" food that we can supply to our aquarium? 

In my opinion, while ground up plankton and krill may have a strong odour, and elicit feeding response, they may not provide the optimum size and nutrient profile for the corals. 

That's why I embark on a journey to search for better coral food.  (Tbc) 

 

 

[jem]

11 hours ago, JiaEn said:

Food for Thought

Imagine you are a colony of super sun coral,  sitting in the shade along some reef slope or a cave. Since you don't have any zooxanthelle, you have to actively capture food from the surrounding to stay alive. So what kind of food would you likely eat? 

Looking at the size of the mouth of these dendrophyllia,  it's only natural to think that probably small pellet sized food is what they eat naturally, because they kind of fit right into the mount of the coral. Yet as I look closely at these animals, I realised that something doesn't add up. 

For a wild colony of dendrophyllia, how likely is it for each individual polyps to have access to large and slow food, on a regular basis? 

Nobody is target feeding these corals 365 days a year. Therefore I felt it is very unlikely that these NPS would demand large particles of food.

 

Pico and Nanoplankton

The ocean is awash with different planktons,  but when it comes to size and availability, there is a lot of difference.  Turns out that the smaller the size of the plankton,  the more abundant they are(Darcy,2014). 

It is then much more sensible for all these sessile predators to go after the most abundant of preys - pico and nanoplankton. These consists of bacteioplanktons,  dinoflagellate, diatoms and a variety of micro algae. The size of these particles ranges from 0.2-20 um (while in contrast, reef roid has a particle size of 150-300 um).

Having looked around for some studies to confirm or disapprove my guess,  I came across several papers. In one study(Leal, 2014),  the author used molecular markers to test if coral species takes up microalgae.  In another (Houlbrèque, 2004) the authors examine the importance of planktonic prey for corals.  They were able to show that the corals do obtain significant organic carbon and proteins from these planktonic food. 

 

Implications? 

Finding the correct food source for corals (regardless of zooxanthelle) is an area for progress to be made. No doubt the commercially available coral supplements are getting better. But could there be some "holy grail" food that we can supply to our aquarium? 

In my opinion, while ground up plankton and krill may have a strong odour, and elicit feeding response, they may not provide the optimum size and nutrient profile for the corals. 

That's why I embark on a journey to search for better coral food.  (Tbc) 

 

 

Smells like something is brewing!!!

[JiaEn]

26 minutes ago, jem said:

Smells like something is brewing!!!

Brewed and testing 

[JiaEn]

Nitrogen Sources for Acropora

let us consider zooanthellate corals (especially Acroporidae). We know they derive much of their required energy through photosynthesis carried out by symbiodinium - symbiotic dinoflagellate inside the coral tissue.  Photosynthesis fixes inorganic carbon such as carbon dioxide and bicarbonate ions into organic carbon.  That much is well understood by most reefers. 

How about other elements?  Such as nitrogen?  These elements must be taken up by the coral,  to support the function of the symbiodinium,  and for it's own growth. Therein lies an important consideration for us reefers: how do we supply nitrogen to the corals? 

No doubt one can raise corals and enchance their colors using a variety of methods.  Yet I believe understand the baseline coral physiology can provide an insight into our reefing approach. 

 

Sources of Inorganic Nitrogen 

Nitrogen is a precious element in the natural reef. The available nitrogen in the reef exists chiefly in three forms.  Ammonium, Nitrate and partculate organic matters. 

Coral holobiont (coral + bacteria and other organism living on the surface of the coral)  is capable of direct uptake of nitrate and ammonium from ambient water.  After all, coral required nitrogen to support the zooxanthelle as well as proteosynthesis.  However,  not all inorganic nitrates are the same. Acropora respond to nitrate and ammonium uptake differently (Fernandes, 2020). It was demonstrated that elevated level of nitrates (0.18ppm,  6 times the nitrate concentration compared to natural seawater) although increase photosynthesis, caused the calcification rate of the coral to decrease, at the same time, these corals showed significant oxidative stress. On the other hand,  when the corals were exposed to 0.054ppm of ammonium, the corals has increased photosynthesis just like when nitrates are added,  but there is little impact on the calcification rate. In addition, corals are much more bleach resistant,  and recover faster post bleach. 

Take note of the parameters in the experiment conducted. The impact of elevated nitrate set in at 0.18ppm nitrate, 25°C. So it's not a stretch of imagination to say that for many hobbyist aquarium,  the corals are often under high level of oxidative stress. 

 

Nitrogen Budget

The dissolved inorganic nitrogen (nitrates and ammonium) while necessary, does not form the bulk of the nitrogen budget. In fact, they only make up about 30% of the total nitrogen budget of the corals. The other 70% is supplied through particulate feeding (Bythell, 1988). Therefore,  corals,  even the phtosynthetic ones, needs to actively capture food from the water column.  Not for their respiration (energy)  needs,  but to obtain sufficient nitrogenous compound. 

 

Takeaways 

In summary,  three ideas we can glean from these researches. 

1. It's better to dose ammonium than nitrate to supplement nitrogen element. 

2. Most aquaria are nitrogen rich anyways. 

3. Particulate food (from fish poop to planktons) is essential for coral health. 

 

One bonus take-away: there is a wealth of rigorous research done by many marine biologists who are not out there to sell us some products. Read those papers. 

[JiaEn]

Aquarium Update

I am in the midst of a small episode of dino outbreak after changing water and thorough cleaning of the sump.

The water parameters doesn't change much pre/post maintenance. Dkh is 7.9(from 8.0), NO3 is 2.5ppm (from less than 5), PO4 at 5ppb (from 3ppb).

This goes to show that a disturbance in the available untested nutrients and elements are the trigger for dino to become more proliferate. 

Coincidentally, after maintenance, the ORP of my system remains low at 230mV (down from 400mV,  and the recovery of the ORP post water change is very slow. This suggest that the drop in the ORP is not due to reducing ions,  but rather the presence of excessive organics.

 

Moving On

Taking sample of the dino and oberve under microscope positively ID them as Amphidinium sp. A rough count suggest that the cell count is 10,000 cells per liter. Which is not that much to begin with. Amphidinium is non-toxic,  and produce little slimes compared to other types of dinoflagellate. So there is little incentive for me to take drastic actions against them. 

The plan is simple.

1. Feed corals more to compensate for nutrient uptake by dino. Yes. Some of these nutrients may fuel the dino growth, but having enough nutrients for corals is the priority. 

2. Mechanical removal by disturbing the sandbed to dislodge ths dino.  The free floating amphidinium cells (50 micron, measured) should be easily trapped by the 30 micron clarisea filter. 

3. Establishe competition and predation. Since amphidinium is non-toxic, herbivores can prey upon them without ill effect. The stombus and cerith in the sand bed should graze on the dino,  even if just a little bit. The plan for introducing competition, is through addition of a variety of heterotrophic bacteria. They should compete with dino for dissolved and particulate organic compounds,  while at the same time, serves as coral food in the form of bacteria plankton. 

That's about it. 

 

[JiaEn]

Reefer vs Dentists

I have recently went for a root canal procedure. Of course,  the dentist told me,  if I were to take care of the cavity sooner, I could have avoided the expensive treatment.  But thinking it's just a cavity or the toothache would probably go away, I put off treating it, forgot about it, until finally I have no choice. 

Like dentistry, like reefing. if us reefers take the chance and expecting small problems to resolve on their own,  we are subjecting ourselves to unnecessary risk. 

 

Hyacinthus and Red Planet 

The latest mishap in my reef started from a fight between two corals. This happens all the time,  not much concern really.  

This time how ever,  the Sting of the red planet caused the hyacinthus to develop a small patch of tissue necrosis near the contested area. Thinking that this will not spread further,  I let the hyacinthus be. 

Unlike previous cases of coral aggression, which stopped rather fast, this hyacinthus went on to complete necrosis and took two other colonies together with it.  One of them is the red planet. Fortunately I did frag out the red planet,  and have since regrafted it back to it's skeleton. 

Hind sight is 20-20. If I have know then, a simple pulling and of fragging of the injured part would prevent the bigger loss.  Luckily sps grows fast,  all is not lost. 

 

Just like going to the dentist regularly, check those corals and repair as needed. A dab of glue may save your most prized possessions. 

 

Added a colony or two to fill the void. 

[JiaEn]

Wholesome Food for Corals

If we accept that corals prey on planktons in the wild, then logically one of the best food we can give to our captive corals is the very same plaktons available in the wild. 

When we attempt to replicate these plankton soup in the aquarium,  there are a few important considerations

 

Live Culture vs Process Food 

Live plankton culture provide much benefits for the aquarium. For one,  they are more stable in the aquarium system compared to processed food - which pretty much starts to degrade as soon as it hits water.  Live culture also engage with the food web of the aquarium.  They may scavage detritus or take up nitrates and phosphates in the water colomn. 

On the other hand, live culture has it's share of challenges. Firstly, the storage and transport of the live culture can be very demanding. Temperature, nutrients, light, various factors needs to be maintained within acceptable range. Secondly,the plankton density in the live culture is generally fairly limited. The culture media also contain various inorganic and trace elements. When live culture is added to the aquarium, these elements are also introduced as well. This can potentially (although unlikely) affect the nutrient in the aquarium system. Finally, there is a (remote) possiblity that live culture may introduce pathogen into the aquarium, harming other organisms. 

On the other hand,  we have plankton cultures which are processed.  The culture can be concentrated so there are more plankton in every ml of the feed. The culture could be treated with UV,  or pasteurized to kill potential pathogens. The final preparations can be stored in a fridge or freezer, even under room temperature for freeze dried algae.  Such preparations has a possibility of rupturing the algal cells. While this could potentially make the food more digestible, it can also cause the food to rapidly degrade in water. 

 

Bacterio-, Phyto- vs Zoo-planktons

The next factor of consideration when formulating a coral diet,  is the composition of different type of planktons. While most corals tries to consume whatever is available in water, we need to be aware that all these different planktons are not the same. 

One of the chief difference is the size. Generally, corals (and clams and sponges)  are specialized to prey on particles of a certain size. For smaller planktons, coral is able to ingest them and digest them in the gut. For larger planktons (especially some zoo-planktons), although the coral is unable to swallow the whole thing,  it is shown that they can digest them outside of their body. So having plankton within suitable range of sizes is essential. 

The challenge though, is that we don't know all that well about what the corals eat. While many experiments are conducted to understand coral nutrition, there are still plenty of gaps to fill. Therefore, I believe having a mixture of naturally occuring planktons is a good approach towards feeding a mixed reef aquarium. 

 

Additives? 

Some compounds can be naturally depleted.  It may be beneficial to artificially maintain the concentration in the aquarium. This is another aspect which I would like to find out more. 

 

[JiaEn]

Muck Diving in the Clarisea

We know automatic fleece traps and remove a lot of nasty things from the water colomn. What exactly do they remove though? 

Just like muck diving in the natural reefs, diving into the microscopic world of gunk on the fleece filter can be an entertaining experience.  

Taking a swab of the matters collected on the fleece, and observe them under the microscope. Then it's a exciting process to search for every little thing. 

 

Dino

As I'm having a outbreak of amphidinium, it is no surprise to find some cells in the fleece. 

 

Diatoms

Now this is a welcome sight. Diatoms can potentially compete with dino and reduce the outbreak; they are also wonderful food for corals and clams. I need more of these. 

 

Zooplanktons

There are remains of zooplankton trapped in the fleece. There are plenty of nematodes as well. 

 

What is This? 

It's not easy to ID many of the organisms in the gunk. Decomposition has already set in, the cells maybe crushed, compressed, ruptured or twisted.  A small swab on the fleece has shown so many interesting things. Surely I will try this some more. 

[JiaEn]

Tank water

How about microscopic life in my display tank? Samples from the water column shows that there is little planktonic live in the display; while samples from the sand bed shows some dino and diatoms. 

Granted,  it is not easy to identify bacteriopankton using optical microscope;  the planktonic life in the water column could be bacteria dominated. At least visually, the display water is nutrition lean in between feeding. I will investigate more about this in the future. 

What I do see is a small number of tissue fragments.  Perhaps some sort of algae bits, left over when fishes graze the rocks.  It's also possible that they are remains of some planktons sheared by aquarium pumps. 

 

Skimmate

When it comes to skimmates,  we imagine it to be one of the most nasty things in the aquarium. It make sense,  because if not, why would we want to remove them in the first place. 

But what does skimmer really remove from the aquarium though. Prevailing understanding tells us that skimmer removes bacteria flocks,  planktons and some dissolved organic compounds. With a microscope on the table, I decided to see for myself. I took a swab of skimmer foam with a toothpick, and smear it on a few drops of tank water (to prevent osmotic shock, I didn't use fresh water). 

Of course, I see the expect stuff. Some unidentified biomass ( probably need to disperse some more),  a few diatoms and dinos (mostly captured by clarisea), and a few algal cells. 

What I didn't expect to see, is the large number of nematodes (marine worms) they are seen to interact with the biomass,  presumably consume them. 

If the sample I took is representative of the skimmer environment,  there must be millions of nematodes in the skimmer. Why don't they make it to the display tank?  Is it possible to recuit them to scavange detritus?  These are interesting questions to ponder. 

 

And on a grander scale,  I think we have to accept that our aquarium system is hardly a homogeneous habitat. It seems more sensible to consider out aquarium as multiple, independent but interconnected biome. 

[JiaEn]

More Nematodes 

Took another look at the skimmer scum. A few interesting preliminary observations after I examine the content of the scum on the neck of the skimmer,  and the skimmate collected in the cup. 

1. The population of nematodes is significantly more dense in the scum compared to the skimmate

2. A few cells of dino can be found in the skimmate,  however, none can be found in scum. 

It warrants further observations, but does nematodes consume dino?  (Specifically Amphidinium sp) 

 

Ciliate

On a non-related observation, a the small scale, many organisms have numerous cilia on their appendages. This is how they improve the swimming efficiency. 

Unknown zooplankton, note the highly ciliated "arms" (and pardon the bubbles due to hasty mounting of slide) 

Another unknown plankton,  note the cilia, presumably for swimming. 

 

Bonus content: a nematode consuming the above plankton.  I looked at this for more than 10 minutes. 

[JiaEn]

Clarisea

The advent of automatic fleece filter, such as the clarisea, brings about a much improved method of mechanical filtration. Gone are the days of floss replacement every couple of days. Not to mention the roller feature regularly remove trapped detritus out of water,  preventing decomposition. The fleece claim to handle a flow rate of up to 5000 lph, and filtering particles down to 20 microns. 

If you remember the chemistry experiment during your teenage years, you would probably recall the horribly slow process of filtration. Once the solid particles start to build up on the filter paper,  the flow rate of liquid grinds to a stop. A typical school lab filter paper has a micron range of 30-50 microns. So how does the clarisea filters smaller particles, and faster?  I think there are a few engineering trick involved. 

 

Large Active Filtration Area

The design of the filter roll allows a large surface area of fleece to participate in the filtering process. And logic will tell us,  the more fleece we use, the more water can pass through. In the normal operation, the water level will sit just below the float switch activation point,  regardless how the clarisea is positioned.  This ensures sufficient fleece material participates in the filtering process. 

 

Large Head Pressue

The pressure different on both side of the fleece is the driving force to push the liquid through. 

When the clarisea is set up correctly,  the liquid level difference is significant. This produce a large driving force to push liquid across the fleece material. Think of this like the booster pump for your RO unit,  the increase of the flow rate is critical for the roll filter to operate effectively. 

 

The Fleece

The heart of the filter is the fleece,  in here plenty of engineering goes into making it work,  well (which is really a basic requirement in filtering media industry). Let's have a look at the fleece material

This is a piece of (kind of) clean fleece under the microscope. Clearly we can see a hole punched out in the material. In fact, if you were to look at the roll filter carefully, you can spot all these hole easily even with just the naked eye. So,  here is the question. How does this fleece carries out filtration?  Is it like a colander where water flows through the hole and the solids strained on it? In another words,  are these holes small enough to trap the detritus in our aquarium? 

Well,  these holes are approximately 1mm in diameter. That's 100x the size of most phytoplankton, 20x the size of a rotifer.  It's too big to "clarify water". The actual filtering is not done by the hole,  but by the fabrics around it. 

Looking at this picture of used (and awfully smelly)  piece of fleecs shows clearly that there in no solid material trapped by the hole. Rather, many cells, and unidentified mass are collected on the web-like polymer. This is where thr number of 20 microns come from. If you look back at the picture of the clean fleece, you can see the unpolluted network of fibers. This is how Clarisea traps detritus for you. 

Why then will they punch holes on the fleece?  Wouldn't this allow water to flow through without being filtered? I believe this is an engineering compromise. If there is no provision for these holes, the flow rate through the fleece material will be too low to be of any practical use. These holes acts as a built-in bypass, to allow the clarisea to handle large flow reasonably well. 

 

This is my take on clarisea fleece, and me appreciating how they kind of make this work. 

 

*on a separate note,  they should really include an "end of roll indicator" just like those receipt machines. So that we don't have to guess how much material is left on the roll. 

[shiraz]

Just finished reading your thread after coming back into the hobby and learning everything from scratch again, I find your almost scientific take on almost everything very captivating, informative and well written for the common man to digest. Looking forwards to more updates and nice tank!


Sent from my iPhone using Tapatalk

[JiaEn]

Thank you @shiraz.

Have been doing quite of bit of...  Unorthodox experiments; more content coming soon .

 

[JiaEn]

Mixed Reef and Nutrition

There is a common saying among reefers: LPS and softies prefer dirtier water, while SPS prefer cleaner water. There are many permutations to this saying.  The dirtiness could mean nitrate or phosphate, it could also be referring to the amount of particulate matter in the water. I, however, think this lines of thought may have their flaws. While I agree that may LPS and soft corals may survive in a greater range of nutrition profile compared to SPS; My observations lead me to belive that LPS, softies and SPS thrive in similar nutrient profiles.  Note that the point of discussion is strictly on nutritions; flow and light (which no doubt affects how coral utilize the nutrients) are not discussed here since much of it has got to do with the position of the coral in the aquarium. 

 

Evidence? 

No,  I didn't do a rigorous study to see what exactly is the "best" environment for LPS and soft corals. I made the privous observation based on the following. 

1. LPS,  SPS, and soft corals may grow on different part of the reef, but their environments are nutritionally similar: extremely low inorganic nitrogen and phosphorus, large amount of nano- and pico- planktons. (Note that the nitrate and phosphate level in unpolluted reef is way lower than most typical aquariums.  Heh,  even in those scientific studies about the elevated level of nitrate,  the elevated concentration is generally kept at 0.2-0.3 ppm.) If the corals are evolved to take up this ecological niche, it will be hard pressed to think that they require much higher level of nutrients to thrive. 

2. There are many successful aquaria with "sps" parameters in which the LPS and softies thrives just as well - many of them with astonishing growth rates.  These anecdotal examples show that LPS can thrive in clean water. 

For my own aquarium, I realised that there isn't too much to worry about for LPS and softies. Leave them in the aquarium  and they will grow on their own - of course, light and flow must be appropriate too. 

This orange Trachyphyllia,  a supposedly dirtly water loving coral, doubled in size (skeletal) in a year. The water parameters is rather consistent at 2.5ppm nitrate,  0.02ppm phosphate (both are already elevated based on unpolluted reef standards). There is no target feeding either. 

 

Like I said,  this is un-rigorous observation. But this is worth a thought,  no?