[Geoff]

here are a few threads that were started in another forum about what is going on in our system. hopefully some of you all will read the information here and start to get a handle on what makes our systems work or not work. I know this may require some reading and those on the internet are allergic to reading threads that are not theirs, but give this thread a go. I am hoping that it will answer most of the questions you may have about reefkeeping. these first three posts may be a bit disjointed. as they came from the other thread. I will try and edit them so that they flow a bit better and lead into each other better.

the biggest things we will be discussing in this thread are the biological process that are going on in our systems. these biological process are what most of the false information that is out there is about. this includes reef forums and LFS. The two main elemental processes we will be discussing are the Nitrogen and Phosphate cycles that are occurring in our systems. these two elements lead to the greatest confusion about what is going on in our little slices of ocean.

There will be a lot of information in this thread. I will be linking to other threads with even more reading and papers on the subject at hand for even further reading. This hobby is easy if you understand what is going on, if you do not care to understand what is going on and listen to a lot of false information out there, then this hobby can be very frustrating and lots of wasted money.
I would anybody to ask questions if they need clarifications. I will try and keep things as short as possible to keep the reading down to a minimum, but some of this stuff is fairly long winded in general.

G~

UPDATE

A sort of Table of Contents for the thread. please feel free to PM any subjects or pages i should add to the contents.

Introduction: Page 1
Nitrogen cycle: Pages 1-2, 22
Phosphates: Page 3, 31
Sources of Phosphates: Page 3
Phosphate Cycle Graphics: Page 35
Early Tank Processes: Page 30
Problems with Sand: Page 4, 19
Sandbed Cleaningage 7
DSB's: Page 9
BB Alternatives: Page 25
About LR: Page 8
LR Purging: Page 19, 26
Cured LR: Page 23
Tank Flow: Page 7
Light: Pages 13-15
Kalkwasser: Page 12, 17
Feeding: Pages 17-19
Zoax: Pages 15-17
Carbon Dosing: Pages 24-25
Tank Self Feeding: Page 27
Conservation of Matter: Page 28
Beer!: Pages 6-7
Bad Experts: Page 19
Definitions according to Spanky: Page 21
My Reference Links: Page 37

 

[Geoff]

Lets start with the nitrogen cycle. we all know that it starts with ammonia, then nitrite, then nitrate, then it is off gassed as N. If all is going fine then there should not be any nitrate in the system. the problem is that nobody goes through what is necessary to remove each of these phases and where the bacteria need to live in order for them to perform their jobs. The process of ammonia to nitrite and nitrite to nitrate take place in oxygenated areas. Any area that has oxygen is going to be able to process up to nitrate. this includes wet/dry filters, sand filters, canister filters, filter socks and sponges, overflows the sides of the tank, anything inside the tank really. the problem comes when we want to convert nitrates to N gas. this require an anoxic (low oxygen) area. the best place for this is the LR. Sand can accomplish this, but the sand bed does not have as much surface are as the LR does for handling the entire nitrogen cycle. the sand bed is more of a 2 dimensional surface while the LR can process over its entire surface. if you are showing nitrates in your system then you have an imbalance between the oxygen areas and the anoxic areas. Once the nitrates are free within the water column they are difficult to remove. this is why people rely on nitrate reducers and algae. All of the bacteria that handle the entire process reside very close to each other. with one layer feeding the other. this is why when the nitrates are free they can not get to the anoxic layers because they are already feeding on the nitrates that the layer right next to them are supplying them. Hard surfaces do not have the depth necessary to create the anoxic layers. This is why those open cell sponges and socks, and wet/dry media are nitrate factories. They just can not provide the anoxic environment to process the nitrates to N gas. OK, now comes the part about the public aquariums. sand filters are extremely efficient at removing ammonia and nitrite because they are high flow oxygen rich areas. we have found out that while ammonia and nitrite are fairly toxic to most marine life, nitrates are not. Nitrates are actually fairly benign. They were given the bad rap because people could test for nitrates, but not test for phosphates easily. They tend to go hand in hand. so people saw their nitrates going up and their tanks crashing and though the nitrates for killing their systems. Not the case, though some inverts are more sensitive to nitrates than vertebrates, once again it was the phosphates. Those extremely large systems are fish only for a reason. they can employ those large sand filters and remove the toxic ammonia and nitrite leaving the nitrates, which can be removed by water changes. though i am not sure how often that occurs on those Uber systems.

G~

 

[Geoff]

Alright here is some reading material to browse through. These are my reference threads for 95% of all of the information i have talked about. Within several of these threads are links to scientific articles for those that are interested delving deeper into the subject. Feel free to book mark these for future reference. I should probably create a thread and sticky it.

I had forgotten about this thread. fantastic read. please, please just read the first page on this one.

about nitrification.

discussion about LR.

OK. those are the most relevant for the current talk about nitrification. I have a whole lot more that i will post when we get more involved in talking about phosphates and what they really do in out systems.

Is everyone following OK? Do I need to expand on anything? Any info from the fuge people that anybody wants to add?

G~

 

[joschend0325]

Haha. Nitrites and Nitrates are zero! Those are easy!! Come on with the Phosphates!!

 

[FutureDoc]

Great idea for a thread, I am following along. Awesome!

 

[Geoff]

We will get to phosphates shortly. It is good to get the nitrate cycle out in the open and understood instead of just knowing that when your test kit says 0 it is go nuts time. :-(

We see plenty of threads out there about people trying to get rid of nitrates, yet nobody seems to have any real answers. Knowing the environment for the different bacteria goes a long way in figuring out exactly how much filtration you have in the system and if it is balance. You will find that you really do not need as much LR as you think. LR is extremely efficient of cycling N through all of its different compounds.

here is a pdf of the basic info on the big display at the Georgia Aquarium. seems awfully simple huh? ;-) of course i think this is overly simplified. skimmers are not replicating anything in nature. i am sure there is other equipment though finding a better description online is proving annoying.

G~

 

[FutureDoc]

I am all for simple! 2/3 pounds of LR per gallon (most artificial).The skimmer, as hobbyist apply it, is not natural but waves do push organic foam into marsh areas to be buried or utilized (close enough?). I am willing to be that terrestrial sources are providing more organics than what waves can remove via skimming. Still aquariums are not replicating nature, we are tying to replicate conditions found in nature... and often it takes very unnatural means. Still the Ga Aquarium is dumbing down their talk about filtration for a more "common" audience and it is tough finding a good credible source for this still... I wonder if they use "purple up" :lol:

 

[Nate_Bro]

I hate when they dumb things down, i want to read the original that the technician wrote up....

 

[Geoff]

Do we have any questions on the nitrate cycle? Does everyone promise not to post questions on why they have nitrates, and how they got there?

G~

 

[Ntvper]

but wait nitrates cant go away due to N gas being too much oxygen in our tanks. but wait theres more. nitrates feed algae like phosphates but wait theres more theres two types of phos in our tank one is soluble which is testable the other non-soluble which is not tested for and that one is the downfall of most tanks as it cant bond with the mag and alk

 

[Ntvper]

no comment? awe man i thought for sure i would spark a debate on phosphates.....guess i'll go try again somewhere else lol. oh btw ill be following along always good to learn something new in this hobby. great idea Geoff for this thread

 

[Geoff]

but wait nitrates cant go away due to N gas being too much oxygen in our tanks. but wait theres more. nitrates feed algae like phosphates

could you elaborate more please on the N gas?

nitrates and phosphates are both great fertilizers for plant (oh sorry algae) growth, an abundance of either will lead to algae problems

but wait theres more theres two types of phos in our tank one is soluble which is testable the other non-soluble which is not tested for and that one is the downfall of most tanks as it cant bond with the mag and alk

we will get into more of this. i have a lot of reading i need to do. its been three years since i had to access this stuff.

G~

 

[Ntvper]

could you elaborate more please on the N gas?

nitrates and phosphates are both great fertilizers for plant (oh sorry algae) growth, an abundance of either will lead to algae problems
G~

oh i was stating that due to most tanks (specially with sumps) tend to be more on the high oxygenated side so the N gas cant escape by normal means. unless that sump has a very slow flow, but none do that as they want the fish to breathe so the agitation is creating more O2. and even with a slow flow refugium, most have macro algae in there and though its slow enough flow (almost no agitation) the by product of that algae eating phos n nitrates is O2....kinda bad mix for the release of N gas in a closed system wouldnt ya say. But dont forget that surface agitation in the DT caused by the powerheads does release 10-40% of the N gas. u can almost see it (with a microscope) as the film (which is actually protein molecules) that is steadly going to overflow and becomes trapped into the sump which if one has a skimmer will be released. But then again the N gas isnt 100% released there either as it doesnt bond with the O2 molecules and gets rotated back into the water column. But it can be siphoned out. But it actually boils down to Nitrates cant be turned into the N gas to be released 100% because of the anoxic bacteria isnt readily available in the closed system (our tanks). So actually what happens is nitrates become trapped in the system and cannot be removed or transfer (so to speak) into the full nitrogen cycle that we need.

 

[hotdogg]

Geoff, just call the aquarium...I have called the aquarium in NY and spoke to them and they couldn't wait to expound on their systems...I once spent three hours talking to one of the Marine biologist there.

 

[Geoff]

the N2 gas that has been released will just go off into the water column then out into the atmosphere to reach standard atmospheric concentrations. the agitation of the water is not as much of a problem as it is with O2 in the water column. N2 is just there. it just happens to be what most of the atmosphere is, but it is not a limiting factor for the holding back the amount of O2 and CO2 in the system. the skimmer is a fantastic air water interface. it allows the the water and the atmosphere to reach equilibrium. the only time there could be a problem with gas exchange would be, like you have suggested, there is a barrier on the waters surface like a film. this can cause an imbalance of dissolved gasses. though when this occurs you will see an decrease in pH from the increase in CO2 in the system. at which point the release of the N2 into the atmosphere is the least of your worries and correcting the CO2 problem with correct the N2 as well.

G~

 

[FutureDoc]

Well, I am a bit confused, Ntvper. You are right about the N2 aspect of the nitrogen cycle is the "weak link" within the tank's cycle. Aquarist add more through feeding than the physical size of the aquarium can process. The tank can not operate as a closed system. I am confused about N not bond with O... that is NOx sometimes as nitrate (NO3). Now it just does not bond with O for no reason, but there is something not right about the right about some part of the statement (or said awkwardly). Also, I do not think the main concern with the N2 is being release via the water surface, I think it is the issue with not enough NO3 conversion to N2

 

[Ntvper]

Well, I am a bit confused, Ntvper. You are right about the N2 aspect of the nitrogen cycle is the "weak link" within the tank's cycle. Aquarist add more through feeding than the physical size of the aquarium can process. The tank can not operate as a closed system. I am confused about N not bond with O... that is NOx sometimes as nitrate (NO3). Now it just does not bond with O for no reason, but there is something not right about the right about some part of the statement (or said awkwardly). Also, I do not think the main concern with the N2 is being release via the water surface, I think it is the issue with not enough NO3 conversion to N2

thats what i said....wasnt it? i was trying to anyways through the processes that people normally see as it happens in the tank.

 

[Fat Tony]

Ok between the two different posts on N2, Im kinda confused....

Nitrate is broken down in the anoxic regions/anaerobic layers in the tank into free Nitrogen gas (N2) which normally can be seen bubbling up out of a tank with a medium to deep sandbed....

The more oxygen saturated the tank is, the deeper the anoxic zones are...

 

[Geoff]

i am not sure that is the case. i do not think that the depth of the anoxic layer changes within the sand bed or the LR. i do not think that the percentage of O2 in the system can change by enough to cause much fluctuation in the anoxic depth. i will see if i can find any info on that though, it is a good point. as long as there is very little flow in an area it does not take much to make it go anoxic. hence the problem if the power ever goes out in our systems. so those little nooks and crannies in the LR can easily create anoxic layers below the areas processing the ammonia and nitrite.

you can even see the N2 bubbles forming on the the LR and releasing into the water column.

G~

 

[Geoff]

not exactly what i was looking for, but could be interesting.

i have a feeling to really find the answer about the anoxic depth changing per O2 concentrations of the solution it would require better access to journals then i have, though i have yet to really pull strings here at Duke in the Biology department.

G~