Coral Tank from Canada (1350gal Display Tank)

[Reefski's]

thanks for the feeding update. i too like the frozen cyclops.

have you had any critters get stuck on the pump intakes?

Carl

 

[kinlayan]

After using minimal amount of biopellets in my aquarium , i never saw dramatic reduction in nitrates or phosphates/ or substantial increase in skimmate but did experience a bleaching event on mainly softies.

I think just like vodka dosing these need fine tuning to work properly , suggested flow rates are still largely experimental , what flow will you use in the fluidised bed?

 

[mr.wilson]

After using minimal amount of biopellets in my aquarium , i never saw dramatic reduction in nitrates or phosphates/ or substantial increase in skimmate but did experience a bleaching event on mainly softies.

I think just like vodka dosing these need fine tuning to work properly , suggested flow rates are still largely experimental , what flow will you use in the fluidised bed?

I agree that the current application of biodegradable plastics as a carbon source is still experimental. The practice lies somewhere between witchcraft and alchemy. There are a lot of people out there using them in fluidized bed reactors, but success stories are few and far between. NP Biopellets have been literally swept up in the hype of fluidized media reactors. On a good note, yours is the first report of coral damage I've heard, but I know that is cold comfort.

All of the scientific data out there shows that biodegradable polymers including NP Biopellets grow only anaerobic bacteria. This is no surprise because we have been using carbon such as vodka/ethanol, lactose, vinegar and glucose/sucrose to dose slow flow denitrifier filters for over 20 years. As a matter of fact, Aqua-Medic has been selling Deniballs for 10-15 years and they are made from the exact same biodegradable polymers http://www.designinsite.dk/htmsider/m0955.htm Other companies like Tetra (Nitrateminus Pearls) have been using polycaprolactone based polymers which are basically the same thing. Here is a good summary on the subject... http://www.reefcentral.com/forums/showpost.php?p=18037114&postcount=2

Aqua-Medic recommends the use of Deniballs in their Nitratereductor filter, which is a slow throughput media reactor with a closed loop recirculating pump. Deniballs look like regular bioballs so they have lots of void space for water to flow through with minimal channeling and no caking/binding like you get with "modern" biopellets. The biopellets in our reactor stick together like pasta if you don't have really good flow through the fluidized reactor. http://www.aqua-medic.com/deniballs.shtml http://www.aqua-medic.com/nitrate_reductor.shtml

There are anaerobic niches within the biofilms that form on media in fluidized reactors, but they tend to grow on the side of the pellet away from strong flow, making fluidized media reactors a poor choice. The only advantage of a fluidized reactor for growing bacteria is the ability to free up excess biofilms (bacterial slime). Anaerobic bacteria will not produce enough biofilms to clog the device as they naturally slough off layers of film as the colony matures. The only benefit to shaking off more biofilm would be to avoid clogging and to feed sponges and corals. There are other more efficient ways of achieving this, such as a plunger device as found on Zeo reactors, manually shaking it up weekly, or a fluidized bed run on a closed loop like the Aqua-Medic Nitraterductor which uses enough flow to uniformly feed water through the whole unit without dislodging too much biofilm.

Our pellets are sticking together in some areas. I'm using a 400 GPH Maxijet which is clearly undersized for the two litres of NP Biopellets to keep moving. The idea of moving the media any more than it already is seems like it would have excessive wash-off of the bacteria. Switching to a high void space media (Deniballs) would be more efficient in my opinion.

I have considered converting the fluidized media reactor into a closed loop recirculating system with a dosing pump to feed it. The plumbing is simple (tee into the influent & effluent of the closed loop with 1/8" John Guest fittings), and we will have a dosing line available with the Profilix. Alternatively, we can plumb a positive feed from the Mangrove/media reactor pump (P3 Poseidon). The only reason why we haven't done so already is we have no measurable nitrate in the system.

I know someone who uses a fluidized reactor on low so the pellets don't tumble, and turns it up for an hour twice a day to feed his azoox corals. He's happy with the set-up, but I would modify it with a DC pump or solenoid feed that can be ramped up to higher flow automatically. When I get the time, I will run an informal experiment comparing the Aqua-Medic unit, a modified closed loop fluidized reactor, and a standard (hype-driven) fluidized reactor. Each test tank can be fed nitrate and phosphate daily and tested for reduction rates.

 

[imthedad]

We are working with "normal/natural looking" lighting so you won't see the fluorescence that you see in your LFS. Thus far we have not purchased any high priced corals. Just about everything has been under $50 retail.

We may pick up a few high end items, but it's more fun hunting for treasure and diamonds in the rough at the LFS. We just ordered some more fish and inverts from Sea Dwelling Creatures in LA today. The order arrives on wednesday... stay tuned.

I used to tranship corals from Indonesia and would stop at Sea Dwelling Creatures and Quality Marine for fish and inverts. They seemed to have good livestock and handling practices. Wish you all the best on your shipment, it's always fun opening "presents" . I've been tagging along and lurking for a LONG time on this thread and felt compelled to thank Peter, yourself, and the rest of the team for your contribution to all of us here at RC, and the hobby as a whole.

 

[nineball]

I used to tranship corals from Indonesia and would stop at Sea Dwelling Creatures and Quality Marine for fish and inverts. They seemed to have good livestock and handling practices. Wish you all the best on your shipment, it's always fun opening "presents" . I've been tagging along and lurking for a LONG time on this thread and felt compelled to thank Peter, yourself, and the rest of the team for your contribution to all of us here at RC, and the hobby as a whole.

Thank you imthedad. Every time we get a post like yours I am reminded just how big this community really is. Thank you for stepping out from the shadows to say Hi and thank you for your support.

Peter

 

[nineball]

thanks for the feeding update. i too like the frozen cyclops.

have you had any critters get stuck on the pump intakes?

Carl

No Carl, I haven't seen any critters pinned to the drain baskets, but, we have decided to create a census as the have been a few notable disappearances that are unaccounted for. One of them was the two spot gobies which both disappeared at the same time. This pair was very close and you would always find them together. I suspect the only logical explanation for the joint disappearance would be that one of them squeezed through the basket and the other just had to follow. I think we are going to have to call on CSI Peter's Tank...........stay tuned!!!

Peter

 

[nuccadoc]

Mr Wilson is there any advantage to using the deniballs reactor over a sulphur denitrator. I have been looking at Koralin's unit for some time then I found the reactors that Aquamedic sells. It seems like they are basically the same concept.....just using a different media.


Scott

 

[Hawkhill6]

I have found that freeze dried cyclopeeze reconstitute very well if soaked and frozen. I soak them in selcon and mix them into the food I make and freeze it in zip lock bags with only enough in them to freeze about 1/4" thick. the food breaks into chunks easily for feeding and the cyclopeeze don't float any more. it is a much more economical way to by the little buggers than in frozen form and pay for all that water.

Thank you all again for everything you share with all of us!

 

[mr.wilson]

Mr Wilson is there any advantage to using the deniballs reactor over a sulphur denitrator. I have been looking at Koralin's unit for some time then I found the reactors that Aquamedic sells. It seems like they are basically the same concept.....just using a different media.


Scott

Sulphur reactors work. The only negative is they can elevate sulphur levels, and I have heard can lower alkalinity, but I don't understand how. Biodegradable polymers work the same they just feed anaerobes carbon instead of sulphur. Carbon can feed beneficial microbes on or adjacent to corals, thus feeding them, so carbon source denitration is likely a better bet.

 

[mr.wilson]

I have found that freeze dried cyclopeeze reconstitute very well if soaked and frozen. I soak them in selcon and mix them into the food I make and freeze it in zip lock bags with only enough in them to freeze about 1/4" thick. the food breaks into chunks easily for feeding and the cyclopeeze don't float any more. it is a much more economical way to by the little buggers than in frozen form and pay for all that water.

Thank you all again for everything you share with all of us!

Thank for the tip, it is a much cheaper way of using them. I tried soaking them overnight in the fridge, but it still floated. I will try your trick tomorrow.

 

[Kipps]

Any chance you can share the "fish order"details to keep the excitement at the normal unaceptable level?

 

[imthedad]

Good morning Peter and team. I was wondering how things went with your shipment from SDC... Terribly excited to see the new additions Looking forward to another great pictorial update.

 

[Scej12]

I have considered converting the fluidized media reactor into a closed loop recirculating system with a dosing pump to feed it. The plumbing is simple (tee into the influent & effluent of the closed loop with 1/8" John Guest fittings), and we will have a dosing line available with the Profilix. Alternatively, we can plumb a positive feed from the Mangrove/media reactor pump (P3 Poseidon). The only reason why we haven't done so already is we have no measurable nitrate in the system.

Hey Shawn,

I would be careful with not having enough flow through the pellets. I found that if they go anaerobic they can produce H2S (that off-putting rotten-egg smell). The key is to ensure you have enough water flow so they don't clog up regularly; while maintaining some contact time within the reactor.

I've been reading through and eventually started contributing some of my own observations on a 500g rehabilitation project to the following thread: http://reefcentral.com/forums/showthread.php?t=1694529.

It's quite lengthy, but I found that most have reached success with the system. Some have given up on it as well, but I think you have to be patient to see the results (if you are trying to come down in levels); and be vigilant with regard to your system parameters... pH in particular as I strongly believe that the new biomass added by the bacterial crew has a dampening effect on pH levels which can lead to other problems in terms of coral growth vs. algae growth. But if working correctly you can really spoil your aquarium charges with an almost obscene amount of food without adversely impacting nutrient levels.

In my particular prototype system it has taken me about 4 mos. to lower nitrate levels from somewhere over 200ppm to approx. 15ppm (measured yesterday) with about 3.5L of pellets. I've only done one 15% water-change in such time and I expect to be at 0ppm Nitrate and phosphate by the middle of February!!!

If I remember correctly post no. 3066 has a really high-level explanation of the biological process/impacts of using solid form carbon dosing.


HTH the perspective a little on pellets...

Once again, just be mindful of not having enough flow. Your mention is the first that I've heard of the pellets using only anaerobic bacteria, as all of the manufacturers have suggested that the pellets establish an anaerobic layer of bacteria underneath an outer aerobic layer. Would you mind letting me know where it was cited that they use only anaerobic so that I can look into this perspective as well? I've been playing around with my own pellet reactor to see if I can't boost efficiency by rationing O2 levels within the reactor. My current setup has a slower flow (non-tumbling) lower portion and a faster flow upper portion. However I have to dislodge the lower portion every couple of weeks to avoid the H2S smell that will begin to filter out as it becomes locked up by bacterial film.

Let me know where you found the info re anaerobic bias with the pellets. Thanks in advance & once again great work and insight so far.... pls keep it coming!

Regards,

Sheldon

 

[mr.wilson]

...all of the manufacturers have suggested that the pellets establish an anaerobic layer of bacteria underneath an outer aerobic layer.

I realize you are using the term "manufacturers" loosely here, as they are merely packaging a raw material manufactured for the plastics industry. These pellets are typically poured into moulds to make biodegradable bottles etc. Aqua-Medic is the only company that I know of that forms the pellets into an aquarium product (Deniballs), and they recommend to use them in an anaerobic media reactor. It makes sense to me, and I have found that their system works.

I will respond to your question with my personal, untested theories however, I would like to hear more details of the "manufacturers" theories

The person I know who tested the NP Biopellets has not published their findings, as it was an informal experiment. They intend to test again and identify all of the bacterial species found to grow on it. They may even get different results this time around??? The point is, we are trying to grow anaerobes, so why do so in an aerobic environment? Yes, there are micro-environments within biofilms (bacterial slime) that support anaerobes, but this is not an efficient means to an end. Of course we should also note that not all denitrifying bacteria are anaerobic, as some are distinctly aerobic in nature.

There is no benefit to growing aerobic bacteria in a denitrator, in fact it is counter productive. Aerobic bacteria should be allowed to grow on substrates where there are localized anaerobic zones (deeper in the sand, and rock). This way residual nitrate is dealt with at the source. The clogging issue can be dealt with mechanically by a closed loop pump. There is no reason why it needs to be a throughput. The Aqua-Medic denitrator filter with deniballs functions very well with no hydrogen sulphide leaching issue.

Slow flow denitrator filters generate hydrogen sulphide as a byproduct of sulphate consumption by anaerobic bacteria as they break down organic matter, this is a good thing. Hydrogen sulphide will off gas, particularly if the media reactor has a bleed valve, or it can be oxidized into less toxic forms of the sulphate cycle, but yes it is toxic. Hydrogen sulphide is found in live rock, sand beds, denitrator filters (particularly sulphur bead denitrators). As long as you don't disturb the gas, it is not dangerous. This is why you should never disturb an anoxic sand bed. The hydrogen sulphide you are experiencing in the lower (more efficient) layers of your reactor only become a problem when you increase the water flow. In my opinion, the issue lies in the throughput, not in the presence of hydrogen sulphide.

The display tank has 0 nitrates and 0 phosphates, so there is no point in modifying the current fluidized reactor at this time. Later, when the bioload and nutrient import is higher and the system matures this issue will no doubt arise. My theory, and it is just that, is that biodegradable polymers will support more bacteria if operated as a slow throughput fluidized reactor if you are using pellets. If you are using bioballs made of biodegradable polymers, they don't need tumbling and they will not clog. As a result, they provide a more stable environment for biofilms. Dislodging of biofilms to feed corals can be carried out manually or with a timed device like an air agitator, water pump, or plunger. This is working under the assumption that there is a need to dislodge a portion of the biofilms. Biofilms grow in layers, on atop the other until it builds up enough to lose stability and sloughs (falls) off. These bacteria will make there way to the display tank naturally as a matter of process.

Stepping back, our goal is to fit a fully functioning anaerobic/denitrifying filter into a small remote device. We just need to do some more testing to size it down and turn up the efficiency.

 

[snadaud]

YES !!! Just got through the last post ! :dance:

I've been reading the thread in my spare time since I discovered it a few days ago, and I feel like a marathon runner crossing the finish line...

Congratulations to Peter, Shawn , all the members of the inner-cabinet and of course the internauts that have contributed to make such a great thread ! I have to say that I really like your approach of considering all options, relying on advice from other people, and trying out the different potential solutions before making the final decision !

I honestly feel that this attitude can only help improve our hobby.

I had a few questions while reading the thread but I should have been taking notes as the only one coming to my numb brain at the moment is about the overflow...

Mr. Wilson is a proponent of sending the surface water to the overflow while trying to keep the "sheet" of water as thin as possible and avoiding to break the surface tension with teeth. I agree 100% with this but in the pictures it seems that the overflow has teeth... How come ?

Also I believe there is a growing number of aquarist using socks on the water outflow from the tank before it gets skimmed in order to filter out the largest particules before they have a chance to decay. Maybe I missed this part but I didn't see any mention of this in the thread and am wondering if these same particules aren't at risk of settling in the gravel inside the overflow which could maybe lead in the long term to a nutrient buildup ?

Regarding the food culture station, I have been planning a "large" tank for a few years (although it is only a nano compared to this one !) and the solution I find the most appealing is co-culturing in a reactor similar to the zinn reactor.

I think that the company selling these in Germany accept to sell separately the micron mesh which keeps the phyto and rotifers separated as well as instruction to build it by oneself. This presents the big advatage of being able to size it properly depending on how much food you want.

I REALLY like the idea of the rotifers waste feeding the phyto culture and the phyto filtering the rotifer water. Another big plus is that the rotifers will be gut loaded with phyto at all time and could then be fed directly.

I would like to set up 3 of these reactors in parrallel, one with rotifers, one with copepods, and a third one with artemias. One option I am considering for adding water to the phyto reactor would be to use unfiltered tank water (after any sediment or particule have settled and been separated) with a metering pump sending it in a long glass tube coiled around a UV lamp.

I think that provided the flow is slow enough and the glass coil long enough bacteries or potential predators should be dead by the time they get into the phyto. There could be issued with temperature of the water in the glass coil but they could probably be solved with a fan.

All these reactors could empty in a refugium-like remote ATF and wave box.

The idea would be to set up a tank which water level would be level with the main display level and use one or two tunze stream which output would be connected to pipes of the proper diameter going to the main tank.

As long as the pipes are full of water there would be a syphon so I think that this tank could work as a remote wavebox without having to drill any new holes in the main display. If it does work it means that the water level in this tank will keep changing and I was considering installing some plastic mesh screens over which turf algae could grow and be harvested. Each screen would be installed at an angle of about 45° to maximize the use of space and so that the changing water level acts as a wave over the surface of the mesh.

The lower half of the tank would always be submerged, and I would plant some caulerpa or other fast growing algae for nutrient export. This is also where I would install the mysis.

I think this tank could only encourage the development of a large diversity of animals in this refugium before they go feed the tank.

Since I haven't tried this yet I absolutely can't garantee that it would work, but would be very interested in hearing your thought about this. If you could even try it out for me it would be even better !! :lol2:

I know Mr. Wilson doesn't like the movement of water generated by a wavebox, but somehow I think it would look more natural to fill and empty one larger tank as the surge would be longer and feel slower compared to the short stacatto you get with a regular wavebox... Once again this is only an opinion and could be completely wrong...

Regarding the delivery of the rotifers, copepods, or artemias to the "refugium" or directly to the tank, a temporary surge strikes me as more efficient than a constant slow overflow. In the case of a constant overflow only the animals around the overflow would be sucked in, and there is a possibility that one particular stage of development of the animal would be predominantely sucked in.

For instance artemias nauplies will be more attracted to the light at the top and will probably represent the larger proportion of the sucked-in animals compared to adult brine shrimps.

The geosapper is a great exemple of a surge-type feeding device: http://reefkeeping.com/issues/2003-07/nftt/index.php

You could even consider disseminating a few geosappers all over the tank to have random additions of live food in the display throughout the day

In any case, to be perfectly honest, while I am pretty sure that adding live food items can only be good for the tank and apparently could also encourage shoaling behaviours in fishes, I can't imagine that it will make a very big change for your corals considering the size of your tank...

Unless of course you dug a second basement under the current one, and dedicated it to food production :dance:


Once again congratulations for this great thread and keep up the good work !!

Hopefully I will one day go through Ontario and have a chance to share a good bottle of wine or two (my treat) with you and your team in front of this magnificient tank...:rollface:

Oh and by the way sorry for the very long post...

Sylvain

 

[nineball]

YES !!! Just got through the last post ! :dance:

I've been reading the thread in my spare time since I discovered it a few days ago, and I feel like a marathon runner crossing the finish line...

Congratulations to Peter, Shawn , all the members of the inner-cabinet and of course the internauts that have contributed to make such a great thread ! I have to say that I really like your approach of considering all options, relying on advice from other people, and trying out the different potential solutions before making the final decision !

I honestly feel that this attitude can only help improve our hobby.

I had a few questions while reading the thread but I should have been taking notes as the only one coming to my numb brain at the moment is about the overflow...

Mr. Wilson is a proponent of sending the surface water to the overflow while trying to keep the "sheet" of water as thin as possible and avoiding to break the surface tension with teeth. I agree 100% with this but in the pictures it seems that the overflow has teeth... How come ?

Also I believe there is a growing number of aquarist using socks on the water outflow from the tank before it gets skimmed in order to filter out the largest particules before they have a chance to decay. Maybe I missed this part but I didn't see any mention of this in the thread and am wondering if these same particules aren't at risk of settling in the gravel inside the overflow which could maybe lead in the long term to a nutrient buildup ?

Regarding the food culture station, I have been planning a "large" tank for a few years (although it is only a nano compared to this one !) and the solution I find the most appealing is co-culturing in a reactor similar to the zinn reactor.

I think that the company selling these in Germany accept to sell separately the micron mesh which keeps the phyto and rotifers separated as well as instruction to build it by oneself. This presents the big advatage of being able to size it properly depending on how much food you want.

I REALLY like the idea of the rotifers waste feeding the phyto culture and the phyto filtering the rotifer water. Another big plus is that the rotifers will be gut loaded with phyto at all time and could then be fed directly.

I would like to set up 3 of these reactors in parrallel, one with rotifers, one with copepods, and a third one with artemias. One option I am considering for adding water to the phyto reactor would be to use unfiltered tank water (after any sediment or particule have settled and been separated) with a metering pump sending it in a long glass tube coiled around a UV lamp.

I think that provided the flow is slow enough and the glass coil long enough bacteries or potential predators should be dead by the time they get into the phyto. There could be issued with temperature of the water in the glass coil but they could probably be solved with a fan.

All these reactors could empty in a refugium-like remote ATF and wave box.

The idea would be to set up a tank which water level would be level with the main display level and use one or two tunze stream which output would be connected to pipes of the proper diameter going to the main tank.

As long as the pipes are full of water there would be a syphon so I think that this tank could work as a remote wavebox without having to drill any new holes in the main display. If it does work it means that the water level in this tank will keep changing and I was considering installing some plastic mesh screens over which turf algae could grow and be harvested. Each screen would be installed at an angle of about 45° to maximize the use of space and so that the changing water level acts as a wave over the surface of the mesh.

The lower half of the tank would always be submerged, and I would plant some caulerpa or other fast growing algae for nutrient export. This is also where I would install the mysis.

I think this tank could only encourage the development of a large diversity of animals in this refugium before they go feed the tank.

Since I haven't tried this yet I absolutely can't garantee that it would work, but would be very interested in hearing your thought about this. If you could even try it out for me it would be even better !! :lol2:

I know Mr. Wilson doesn't like the movement of water generated by a wavebox, but somehow I think it would look more natural to fill and empty one larger tank as the surge would be longer and feel slower compared to the short stacatto you get with a regular wavebox... Once again this is only an opinion and could be completely wrong...

Regarding the delivery of the rotifers, copepods, or artemias to the "refugium" or directly to the tank, a temporary surge strikes me as more efficient than a constant slow overflow. In the case of a constant overflow only the animals around the overflow would be sucked in, and there is a possibility that one particular stage of development of the animal would be predominantely sucked in.

For instance artemias nauplies will be more attracted to the light at the top and will probably represent the larger proportion of the sucked-in animals compared to adult brine shrimps.

The geosapper is a great exemple of a surge-type feeding device: http://reefkeeping.com/issues/2003-07/nftt/index.php

You could even consider disseminating a few geosappers all over the tank to have random additions of live food in the display throughout the day

In any case, to be perfectly honest, while I am pretty sure that adding live food items can only be good for the tank and apparently could also encourage shoaling behaviours in fishes, I can't imagine that it will make a very big change for your corals considering the size of your tank...

Unless of course you dug a second basement under the current one, and dedicated it to food production :dance:


Once again congratulations for this great thread and keep up the good work !!

Hopefully I will one day go through Ontario and have a chance to share a good bottle of wine or two (my treat) with you and your team in front of this magnificient tank...:rollface:

Oh and by the way sorry for the very long post...

Sylvain

Sylvain, welcome to our thread community. Every post like this makes this thread a better reward for those who remain part of this group and for this I thank you. There are a number of excellent points you have raised which I know I will be discussing with Mr. Wilson later today. I will let him respond to most as he truly has the expertise to respect your suggestions. I will say however the observation you make about the teeth in the overflow is accurate. I had a different project manager at the beginning of this build who had......shall we say........different ideas about how things should be done. Mr. Wilson unfortunately inherited some of those early decisions and had to live with some of the consequences. He has worked with me to correct a number of inappropriate ideas but some were more difficult than others to fix and the teeth on the overflow is one of them. We are still considering options to correct this but other priorities have kept us from focusing on a fix once and for all.

As to the other excellent points you raise, I'm sure you will be hearing from Mr. Wilson very soon. Also if you do find yourself in our neck of the woods you will be welcome to sit with us and enjoy a glass of wine........it would be a pleasure.

Peter

ps. Today we are concentrating on the Profilux controller and trying to bring it on-line to assist in managing the entire marine ecosystem.

 

[Scej12]

I realize you are using the term "manufacturers" loosely here, as they are merely packaging a raw material manufactured for the plastics industry. These pellets are typically poured into moulds to make biodegradable bottles etc. Aqua-Medic is the only company that I know of that forms the pellets into an aquarium product (Deniballs), and they recommend to use them in an anaerobic media reactor. It makes sense to me, and I have found that their system works.

Loosely indeed... you are correct; I should have said distributors.... Until you mentioned it I didn't make the connection between deniballs and the pellets - that certainly makes sense.

I will respond to your question with my personal, untested theories however, I would like to hear more details of the "manufacturers" theories

The person I know who tested the NP Biopellets has not published their findings, as it was an informal experiment. They intend to test again and identify all of the bacterial species found to grow on it. They may even get different results this time around??? The point is, we are trying to grow anaerobes, so why do so in an aerobic environment? Yes, there are micro-environments within biofilms (bacterial slime) that support anaerobes, but this is not an efficient means to an end. Of course we should also note that not all denitrifying bacteria are anaerobic, as some are distinctly aerobic in nature.

This is an interesting point, and in particular the acknowledgment that there are various processes of denitrification, in disparate levels of O2 saturation (or lack thereof). I have somewhere in my dusty basement, a couple of small books by Dr. Bob Goemans; and one of which was detailing the function of a Jaubert Plenum. Kind of dated now but the point I remember dealt with the different levels and terms used to describe O2 saturation: aerobic - O2 rich; anaerobic - O2 absent; and anoxic - O2 deficient... Of note was the mention by Dr. Goemans that the Jaubert plenum worked primarily due to the differences between anaerobic and anoxic denitrification. If I remember correctly (now pls forgive me if I misquote anything since I read these books some time ago and I'm already enjoying the memory of someone 100 years older than I am currently) it was stated that anaerobic denitrification relies on a process of destruction - i.e. in the absence of oxygen bacteria strips the oxygen molecules from nitrates to reduce the nitrate to a less harmful form of nitrogen gas. By inserting the plenum into the equation, and limiting the sand depth to 4 inches or so, the deep sandbed, according to Dr. Goemans, only reaches an anoxic (oxygen-low) state which again according to Goemans allows for a more efficient form of denitrification, as the bacteria which thrive in a low O2 environment achieve denitrification through assimilation, as opposed to destruction. (once again pls don't quiz me on this as I will have to go find the books to provide any more details):twitch:
The memory that I have kept ever since reading about this 5 or so years ago is that anaerobic (or destructive based) denitrification was said to have been the most inefficient form of denitrification... and I think the whole bacterial driven, carbon dosing phenomena was likely a natural evolution to the aforementioned account [at least in my mind's eye anyway]


There is no benefit to growing aerobic bacteria in a denitrator, in fact it is counter productive. Aerobic bacteria should be allowed to grow on substrates where there are localized anaerobic zones (deeper in the sand, and rock). This way residual nitrate is dealt with at the source. The clogging issue can be dealt with mechanically by a closed loop pump. There is no reason why it needs to be a throughput. The Aqua-Medic denitrator filter with deniballs functions very well with no hydrogen sulphide leaching issue.

I'm guessing the question we are discussing has more to do with the different types of denitrification processes that exist. As alluded to earlier, disparate levels of O2 saturation present different forms of denitrification, and according to at least one credible source, it has been said that anaerobic/destructive denitrification is perhaps the most inefficient type. I'm no scientist, just an interested hobbyist with particular intrigue for figuring out and building/facilitating environmental processes based on the work of the real 'big-heads' who dissect, inspect, and analyze these things on a microscopic level.

By definitions of past, denitrators & aerobic bacteria don't mix; however with the more recent dawn of carbon dosing (aka bacterial driven filtration); considering everything I've been able to gather about the process, denitrification is achieved by process of assimilation. That is, all living things consume nitrogen; phosphorus; and carbon. These are the foundational building blocks of DNA structures from what I'm told; and all must be present for growth as I understand it. Therefore, without carbon (C), the life-form (bacteria in this case) cannot make use of the N & P; without P, N & C cannot be used; and the same goes for the absence of N... C & P cannot be used, and there is a certain ratio in which all of the above are used - much more C than N; and much more N than P. In the post (#3066) I quoted prior, TMZ from the Reef-Keeping Mag has contributed the following:

"...Living things consume organic carbon(C),.phosphorous(P) and nitrogen(N) as food. Autotrophic (photosynthetic organisms) produce much of the inorganic carbon (sugar) they need.Some organisms like heterotrophic(non photosynthetic) bacteria rely on organic carbon .They also respire the O from NO3 freeing the N to form N2 gas when living in anaerobic conditions.

The Redfield ratio circa 1934, is a measure of the C:N ratio in phytoplankton(106 parts C :16N;1P). Different organisms have different ratios but generally the Redfield ratio gives perspective on the relative amounts of CNP in marine organisms. Significantly more C than N and N than P..."

The deliberate strategy of growing bacteria via carbon dosing (sugar; vinegar; ethanol; and now biodegradable polymers), from what I understand is a step beyond anaerobic denitrification as evidenced by the initially anticipated [aquarium-wide] bacterial bloom that takes place within the [aerobic] water column for those successfully igniting the pellet process; or the inadvertent bloom which occurs if one doses too much vodka. In all forms of [liquid & solid] carbon dosing the supplied carbon source makes it possible for aerobic as well as anaerobic bacterioplankton to metabolize the N and P available within the nitrates and phosphates we are so desperately trying to rid our systems of... and in all cases the bacteria along with their assimilated N & P are removed from the water column by good protein skimming. This is probably the major reason why carbon dosing never works without a skimmer.

I was thinking along similar lines as you suggested that the anaerobic and more likely anoxic bacteria could possibly do more work than the aerobic strains within my reactor which is why I was about to set my reactor on recirculation mode (as suggested) about a month ago, but someone on the same forum I was participating on made an account of a rotten egg smell after a few days of trying a low flow setup... for that reason I held off on the recirculation change but did create a zone as mentioned where the flow is significantly lower; and the environment is very likely anoxic/approaching full anaerobic. I haven't had the guts to leave it compacting for longer than a couple of weeks for fear of stinking up the condo lobby that it is located in, but now based on what you said about H2S only becoming an issue if disturbed, I might give it a try, and simply take the whole reactor outdoors when it's time for cleaning:eek1:

I haven't had the opportunity to play around with any of the traditional nor more recent anaerobic denitrators personally. I was just about to get into a sulfur reactor on a certain large public aquarium that I'm subcontracted to look after, but the primary contract holder was not prepared to take the risk of stinking up the entire building should the flow rate be thrown off for some reason. On another forum, I read about someone wiring up an ORP controller & solenoid to manage redox levels between -170 and -250 which is apparently the sweet spot for sulfur based denitrification, but just when I was getting all interested in that idea, out came the bio-pellets and BAMMM! I was sold!! As far as I have been able to read about and validate by my own usage, the biggest benefit of the new fluidized approach made possible by carbon dosing is the fact that you need not get involved in that balancing act of using precise flow-rate through your reactor in order to avoid the negative possibilities associated with low flow denitrators.



Slow flow denitrator filters generate hydrogen sulphide as a byproduct of sulphate consumption by anaerobic bacteria as they break down organic matter, this is a good thing. Hydrogen sulphide will off gas, particularly if the media reactor has a bleed valve, or it can be oxidized into less toxic forms of the sulphate cycle, but yes it is toxic. Hydrogen sulphide is found in live rock, sand beds, denitrator filters (particularly sulphur bead denitrators). As long as you don't disturb the gas, it is not dangerous. This is why you should never disturb an anoxic sand bed. The hydrogen sulphide you are experiencing in the lower (more efficient) layers of your reactor only become a problem when you increase the water flow. In my opinion, the issue lies in the throughput, not in the presence of hydrogen sulphide.

I can appreciate your point here and do agree. I also thought the ammonia pockets were the typical threat you encounter when disturbing deep sand beds.

While I was seriously considering employing a sulfur denitrator; I was introduced to one of our colleagues here in the GTA. I won't use his name because I don't believe in publicly quoting people without giving them a heads up first. But in any event this particular person has two separate degrees (environmental engineering & microbiology I think) both useful to our hobby; and at that time he lived and swore by sulfur denitrators. Once again this was prior to the establishment of solid form carbon dosing, so perhaps he may have changed his aquarium spec strategies by now. In our conversation, I asked him about the risks of H2S since he installed a sulfur reactor in nearly all of his new installations. He responded in saying that sulfur denitrators do in fact release sulfates into the water column, but these are not usually a problem if you have a well oxygenated aquarium. He continued to say that if you have low flow zones in your aquarium system (behind liverock, etc.) then the sulfate (SO4) can then be reduced to Hydrogen Sulfide (H2S) which will give you that rotten egg smell. I gathered that the SO4 will be reduced to H2S by the same process that NO3 is reduced to N2 in anaerobic environments - i.e. bacteria requiring O2 will steel it from the sulfate & nitrate molecules (but that was just an educated guess on my part).

The display tank has 0 nitrates and 0 phosphates, so there is no point in modifying the current fluidized reactor at this time. Later, when the bioload and nutrient import is higher and the system matures this issue will no doubt arise. My theory, and it is just that, is that biodegradable polymers will support more bacteria if operated as a slow throughput fluidized reactor if you are using pellets. If you are using bioballs made of biodegradable polymers, they don't need tumbling and they will not clog. As a result, they provide a more stable environment for biofilms. Dislodging of biofilms to feed corals can be carried out manually or with a timed device like an air agitator, water pump, or plunger. This is working under the assumption that there is a need to dislodge a portion of the biofilms. Biofilms grow in layers, on atop the other until it builds up enough to lose stability and sloughs (falls) off. These bacteria will make there way to the display tank naturally as a matter of process.

If you have the proper amount of biopellets and they do infact get inoculated with the right strain of bacteria, then you will likely never see a rise in nitrate and phosphate, and therefore will likely not need to modify your current setup. Also keep in mind that the effluent from the pellet reactor should be directed near or directly into the skimmer intake so that you export as much of the bacterioplankton and their captured nitrates/phosphates as possible... some will inevitably make it into the system as protein skimmers cannot remove everything that pass through them. Also keeping in mind that the phosphate and nitrate levels can be limiting factors for each other; there could be a time at which you read 0 nitrates, but do have phosphates. This is because the bacteria will not be able to metabolize one in the absence of the other. This is also why it is still recommended by all of the 'distributors' and those having experience with the system to continue using gfo once your nitrates have reached rock bottom.

Stepping back, our goal is to fit a fully functioning anaerobic/denitrifying filter into a small remote device. We just need to do some more testing to size it down and turn up the efficiency.

In any event - looks like you have all of the right tools/equipment which you will eventually tweak toward perfection. That to me is the most interesting and rewarding part of this hobby - so have fun for all of us looking on with excitement:wave:.

I've learned a lot reading about all of the trials and tribulations presented on the N/P thread, as well as my own tinkering with the system on a 500g prototype I'm working on. This is why I am able to assemble the thoughts above; offered up for your consideration if desired. Feel free to correct any misinformation as this whole thing is just one great big learning experiment that we all enjoy immensely!!

Cheers & keep up the great work!:beer:

Sheldon

 

[Elliott]

Snaduad: that geosapper is interesting, thanks for posting

 

[dave.m]

I agree that the current application of biodegradable plastics as a carbon source is still experimental. The practice lies somewhere between witchcraft and alchemy. There are a lot of people out there using them in fluidized bed reactors, but success stories are few and far between. NP Biopellets have been literally swept up in the hype of fluidized media reactors. On a good note, yours is the first report of coral damage I've heard, but I know that is cold comfort.

On a sad note, then, here is another recent report of similar problems.

Dave.M

 

[mr.wilson]

YES !!! Just got through the last post ! :dance:

I've been reading the thread in my spare time since I discovered it a few days ago, and I feel like a marathon runner crossing the finish line...

Congratulations to Peter, Shawn , all the members of the inner-cabinet and of course the internauts that have contributed to make such a great thread ! I have to say that I really like your approach of considering all options, relying on advice from other people, and trying out the different potential solutions before making the final decision !

I honestly feel that this attitude can only help improve our hobby.

I had a few questions while reading the thread but I should have been taking notes as the only one coming to my numb brain at the moment is about the overflow...

Mr. Wilson is a proponent of sending the surface water to the overflow while trying to keep the "sheet" of water as thin as possible and avoiding to break the surface tension with teeth. I agree 100% with this but in the pictures it seems that the overflow has teeth... How come ?

Also I believe there is a growing number of aquarist using socks on the water outflow from the tank before it gets skimmed in order to filter out the largest particules before they have a chance to decay. Maybe I missed this part but I didn't see any mention of this in the thread and am wondering if these same particules aren't at risk of settling in the gravel inside the overflow which could maybe lead in the long term to a nutrient buildup ?

Regarding the food culture station, I have been planning a "large" tank for a few years (although it is only a nano compared to this one !) and the solution I find the most appealing is co-culturing in a reactor similar to the zinn reactor.

I think that the company selling these in Germany accept to sell separately the micron mesh which keeps the phyto and rotifers separated as well as instruction to build it by oneself. This presents the big advatage of being able to size it properly depending on how much food you want.

I REALLY like the idea of the rotifers waste feeding the phyto culture and the phyto filtering the rotifer water. Another big plus is that the rotifers will be gut loaded with phyto at all time and could then be fed directly.

I would like to set up 3 of these reactors in parrallel, one with rotifers, one with copepods, and a third one with artemias. One option I am considering for adding water to the phyto reactor would be to use unfiltered tank water (after any sediment or particule have settled and been separated) with a metering pump sending it in a long glass tube coiled around a UV lamp.

I think that provided the flow is slow enough and the glass coil long enough bacteries or potential predators should be dead by the time they get into the phyto. There could be issued with temperature of the water in the glass coil but they could probably be solved with a fan.

All these reactors could empty in a refugium-like remote ATF and wave box.

The idea would be to set up a tank which water level would be level with the main display level and use one or two tunze stream which output would be connected to pipes of the proper diameter going to the main tank.

As long as the pipes are full of water there would be a syphon so I think that this tank could work as a remote wavebox without having to drill any new holes in the main display. If it does work it means that the water level in this tank will keep changing and I was considering installing some plastic mesh screens over which turf algae could grow and be harvested. Each screen would be installed at an angle of about 45° to maximize the use of space and so that the changing water level acts as a wave over the surface of the mesh.

The lower half of the tank would always be submerged, and I would plant some caulerpa or other fast growing algae for nutrient export. This is also where I would install the mysis.

I think this tank could only encourage the development of a large diversity of animals in this refugium before they go feed the tank.

Since I haven't tried this yet I absolutely can't garantee that it would work, but would be very interested in hearing your thought about this. If you could even try it out for me it would be even better !! :lol2:

I know Mr. Wilson doesn't like the movement of water generated by a wavebox, but somehow I think it would look more natural to fill and empty one larger tank as the surge would be longer and feel slower compared to the short stacatto you get with a regular wavebox... Once again this is only an opinion and could be completely wrong...

Regarding the delivery of the rotifers, copepods, or artemias to the "refugium" or directly to the tank, a temporary surge strikes me as more efficient than a constant slow overflow. In the case of a constant overflow only the animals around the overflow would be sucked in, and there is a possibility that one particular stage of development of the animal would be predominantely sucked in.

For instance artemias nauplies will be more attracted to the light at the top and will probably represent the larger proportion of the sucked-in animals compared to adult brine shrimps.

The geosapper is a great exemple of a surge-type feeding device: http://reefkeeping.com/issues/2003-07/nftt/index.php

You could even consider disseminating a few geosappers all over the tank to have random additions of live food in the display throughout the day

In any case, to be perfectly honest, while I am pretty sure that adding live food items can only be good for the tank and apparently could also encourage shoaling behaviours in fishes, I can't imagine that it will make a very big change for your corals considering the size of your tank...

Unless of course you dug a second basement under the current one, and dedicated it to food production :dance:


Once again congratulations for this great thread and keep up the good work !!

Hopefully I will one day go through Ontario and have a chance to share a good bottle of wine or two (my treat) with you and your team in front of this magnificient tank...:rollface:

Oh and by the way sorry for the very long post...

Sylvain

Congratulations! I was reluctant to start in on this thread back when I found it at 20 pages, but I'm glad I did.

If that is just one question, then I don't want to be around when you remember all of the others

I inherited a few things with this tank. Some were easy to change, while others weren't. The overflow has teeth and the tank isn't level. At some point in time, I will glue a strip of acrylic against the back of the teeth at the "deep end" of the tank to level the two overflow boxes. If I'm up to the challenge, I could cut the teeth out and add a horizontal barrier, but it isn't a priority. We are losing a bit of efficiency in the surface skimming department and we are losing some small fish through the over-sized teeth in the overflow boxes. Adding eggcrate or gutter guard mesh is another modification we have considered.

The sump has four 7" x 16" 100 micron filter bag/socks. We have another bag post protein skimmer to reduce the millions of bubbles that the RK2 protein skimmer bleeds into the refugium. The micro-bubbles are diffused before they make it to the sump, but it is causing green cyanobacteria and reducing light in the refugium.

The practice of culturing live food will be a major turning point in the hobby. As you have stated, gut loaded rotifers are not only healthy, they can actually improve water quality and minimize organic waste during nutrient import (feeding). The hobby has evolved from focusing on lighting, to flow, and now live plankton. Each of these progressions has been more significant than the last. One of the major criteria of good flow is to keep POC (particulate organic carbon/food) suspended. Of course we need that food to be there in the first place. You are better to have less flow and more food, than great flow with nothing to deliver to the waiting coral mouths.

I had never heard of the Zinn reactor, thanks for the info. I don't know if this link will work, but looking at the picture, I saw another way of automating the import/dosing of food items such as phytoplankton http://glassbox-design.com/2008/zc-aquarientechnik-the-zinn-phytoplankton-reactor/ The green lift tube could be set up with an air pump and a timer. The timer could turn the air pump on for a few seconds and the phytoplankton would be propelled into the rotifer tank. This method is more efficient and effective than a water pump due to cost, reliability, and the fact that the tubing would not trap live phytoplankton or whatever live food you are delivering. The problem that arises with using peristaltic pumps is the stuff that gets stuck in the lines as they don't drain between cycles. I will read up on semi-permeable membranes, as it has been a long time since grade 9 Science. I will also draw up a multi chambered air lift tank and consider the idea.

I don't have much experience with rotifer and phytoplankton culture, so I'm not sure what the risks of contamination with bacteria or predator introduction would be. Perhaps a fine sediment filter will suffice? A small ozone reactor or nano UV sterilizer may be worth the trouble. I will be studying the issue in the near future.

I don't have a problem with wave or surge devices, as long as the waves look natural, they run silent, there's no salt creep or splashing, and no bubbles. A Carlson surge device will back-siphon as you describe, and if you set up a dam & weir system, you could somewhat regulate how many rotifers or shrimp would get swept away with the surge. To clarify, the feeding tank that I designed does work on an occasional surge, rather than a constant drip. I guess surge is a strong word, since it will be fed by a peristaltic (dosing) pump.

Thanks again! for the Geosapper link, I had never heard of the device. These types of feeding devices will be on every reef tank one day in the not so distant future. I will do some more work on the design of our feeder, but I know we will have many prototypes before we put the "Best Practice" sticker on it I will be looking forward to your visit to celebrate :beer: