Zeovit, potassium, and venturi skimmers

[UK_Pete]

@schabiazabi - I dont really agree that these points are not really verified. Maybe you are right but if so I think maybe you are asking for a degree of verification which is hard to attain.

Much of the really good stuff for instance is only available if you have access to the journals, I used to have this, alas no more. But still you can frequently find good papers if you look hard. For instance heres one I have open at the moment:

http://mediteran.aslo.net/lo/toc/vol_53/issue_2/0824.pdf

'Nitrogen and phosphorus co-limitation of bacterial productivity and growth in the oligotrophic subtropical North Atlantic'

This study took water from the ocean, and tested it for various parameters including bacterial counts and nutrients. They then spiked samples of the water with various combinations of nutrients and DOC, and retested it for many parameters including bacterial production and quantity. They also spiked samples with thymidine labelled with tritium, a radioactive isotope, to allow a sensitive test of biological activity (the reason for using a radioactive hydrogen atom instead of a normal hydrogen atom is so they can follow the incorporation of that particular atom into various biological pathways - its a method to directly label a set of atoms, and trace their use using something called liquid scintillation, so you can trace their use very specifically and accurately even down to extremely low quantities of a few molecules in several ml of liquid).

They accurately measure ammonia and phosphate to about 250 parts per trillion, and nitrate to about 1.5 parts per billion.

In this study they found that their samples were mostly N and P limited. You can read the whole paper for the whole story, its long and theres a lot more to it that what I just typed! But its a good example of what you can find if you look hard for the type of questions you are asking. I am not saying that this particular one will answer your questions, or that there is any study that will answer all your questions, but I think this one is worth reading as its quite along the lines you are discussing.

In the previous link I posted you can see that on the GBR, you can find levels around 1 ppm of DOC, but only about 3 ppb of inorganic N or P - frequently less than 1 ppb. So these waters are obviously not limited by DOC. I dont know about the reef you posted, Ill see if I can find any data for it - I never heard of it before, but I am no expert, just someone who likes reading scientific papers

As for why are corals thriving in a low DOC or low bacteria environment - I guess its unlikely to be as simple as corals having only one food. Seems to me a balance probably exists on successful reefs. My thinking is that corals can probably use nutrients from various sources. Some papers I read a few weeks ago showed that nutrient budgets in corals are varied and that suggests they might be flexible. I personally think that maybe one way to keep corals happy in a tank is a high bacteria, low nutrient system, but that there might be alternative water parameters with slightly higher inorganic nutes for instance.

Got to go but have a look at those links and tell me what you think of them, whether you feel they to address the questions any better. The GBR link interesting tables are around page 20 btw.

 

[robf]

Would an improvement to water quality be realized were a system developed to culture bacteria populations from skimmate? Sort of a bacteria refugium that was somehow dosed back to the tank? Using strains from skimmate would ensure a line of bacteria that was indeed skimmable. How quickly could a culture be produced before it was ready to be returned? Im envisioning a closed loop bio pellet reactor or a plastic tub of some sort for the culture to grow in. Is this feasible?

 

[schabiazabi]

^ So far a very good article. There it is, right off the bat in Abstract paragraph:

additions of labile DOC (glucose) provided no stimulation unless N and P were also added.

LOL. What can a carbon dosing, or zeovit preacher say to that? If your N and P are being removed (declining) by skimmer and etc, how can carbon dosing work? Zeovit system is suppose to have low N and P, so how is high bacteria count sustained with little N and P? So which one is it, as you can't have both. Having fun yet?

 

[UK_Pete]

@schabiazabi

additions of labile DOC (glucose) provided no stimulation unless N and P were also added.

LOL. What can a carbon dosing, or zeovit preacher say to that?

I guess from 'lol' you see a contradiction somewhere but I dont see it. If I am missing something please explain. I am sure you realise that in the context, 'additions of glucose provided no stimulation' means 'the system already had excess carbon'. So, the systems they studies were limited by N and P as they later explain, and specifically not limited by carbon, as addition of carbon had no stimulatory effect. If the addition of carbon had stimulated the system to grow in some way, then carbon would have been proven to be a limiting factor prior to the addition (in the natural state as sampled).

So, in order to replicate that system in an aquarium, we would need to ensure DOC was in excess against N and P - and since we have lots of N and P in our systems typically, that means we need to dose DOC. We feed a food imbalanced towards nutrients with insufficient carbohydrates for that food to be a balanced food for bacteria (ie high protein food).

Zeovit system is suppose to have low N and P, so how is high bacteria count sustained with little N and P?

Well bacteria typically have far more carbon than nitrogen, and far more nitrogen than phosphorus. So to sustain lots of bacteria you need lots of carbon, less nitrogen, and less still phosphorus. If you dose excess carbon you allow the system to become limiting on something other than carbon, which typically becomes N and or P. Marine heterotrophs have evolved to be fairly adaptable to the exact amount of P used in their biomass, taking up excess P in times of plenty (called 'luxury') and stretching the P reserves in times of little P. If you dont feed carbon and you do feed high nutrient food like fish, clams, squid, etc, then carbon will become the limiting factor and your N and or P will be allowed to rise. With carbon in excess, uptake of N and P by bacteria can continue down to the part per billion level or even lower (IIRC I saw 10 nmol in that paper which would be less than 1 part per billion of N or P).

In the zeovit system, the theory is that N and P are low simply because they are turned into organic forms very quickly, which test kits do not measure. So since the heterotrophs are very fast to assimilate the inorganic N and P, there is never any to measure. Whether the bacteria are helpful in themselves to the corals, or just the fact that the inorganic nutes are kept low is helpful to the corals, or the fact that the bacteria might convert dissolved inorganic nutrients into dissolved organic nutrients, I dont know if anyone has any opinions on.

If you dont dose carbon, nitrifying bacteria will consume ammonia nitrogen, and will be less in numbers (far less biomass is produced by this process). So in simple terms, the answer to the zeovit question is that adding carbon converts the system from a nitrifying to a heterotrophic system, and a far greater level of bacterial biomass is produced by the latter, hence the 'high bacterial count sustained'. The heterotrophs are far faster working and so more efficient at keeping the system low nutrient all other things being equal. Additionally they directly consume ammonia rather than having to allow the ammonia to pass through several steps, each of which will be limited by factors like diffusion etc.

I am not convinced myself of the mantra of carbon dosing creating bacteria which are skimmed. I think an alternative (although perhaps not exclusive) process is that the carbon simply allows recycling of nutrients several times. So while nutrients are locked up in bacterial biomass (free or attached to substrate) they are not detected by test kits. If bacterial biomass dies it is degraded by other bacteria which need fresh supplies of carbohydrates (dosed carbon) to perform this process. Bacteria need carbohydrates (energy) to perform their biological functions and continually adding carbohydrates allows them to do so.

 

[robf]

@schabiazabi


I am not convinced myself of the mantra of carbon dosing creating bacteria which are skimmed. I think an alternative (although perhaps not exclusive) process is that the carbon simply allows recycling of nutrients several times. So while nutrients are locked up in bacterial biomass (free or attached to substrate) they are not detected by test kits. If bacterial biomass dies it is degraded by other bacteria which need fresh supplies of carbohydrates (dosed carbon) to perform this process. Bacteria need carbohydrates (energy) to perform their biological functions and continually adding carbohydrates allows them to do so.

Thanks for the detailed explanation of how zeovit works. I learned something new. Is there a point where carbon dosed tanks can no longer recycle nutrients? Whereby it reaches its maximum threshold of biomass? How would a tank in this state indicate it has reached this state?Would it crash? In practical terms are we talking a great number or years before this would become problematic or can husbandry prevent this from happening?

 

[schabiazabi]

I am sure you realise that in the context, 'additions of glucose provided no stimulation' means 'the system already had excess carbon'.

Not exactly. They keep repeating this:

net heterotrophic bacterial productivity and biomass in the central North Atlantic were nitrogen and phosphorus co-limited

But let's assume, there was excess of carbon, but co-limited P and N. This is where things get funny. Since bacteria consumes, more carbon than P and N, and more N than P, with all this excess of carbon, how come bacteria did not deplete N and P to zero???

And another question, if limited N and P can not be removed by bacteria in the ocean (oligotrophic location!!!), how can it be removed in the tank, where we know the proportions of N and P are way higher?

Another related question: if DOC is not zero (in our reef tanks), why would you dose carbon? Wouldn't bacteria remove all C since N and P is available?

 

[Randy Holmes-Farley]

And another question, if limited N and P can not be removed by bacteria in the ocean (oligotrophic location!!!), how can it be removed in the tank, where we know the proportions of N and P are way higher?

Another related question: if DOC is not zero (in our reef tanks), why would you dose carbon? Wouldn't bacteria remove all C since N and P is available?

No organisms can take N and P to zero.

The presence of DOC does not imply easy consumption by bacteria. The things we add are easily consumed, rapidly reducing N and P when the molecules naturally present may not.

I don't think there is really any paradox about the issues mentioned above.

 

[UK_Pete]

@Schab,

But let's assume, there was excess of carbon, but co-limited P and N. This is where things get funny. Since bacteria consumes, more carbon than P and N, and more N than P, with all this excess of carbon, how come bacteria did not deplete N and P to zero???

When they added N and P together, the system showed signs of using it (growth, production of biomass etc). In the process it used carbon already in the system, hence the system was limited on N and P as they say, and there was enough carbon and other trace elements for this growth. As Randy said the reason the N and P were not absolute zero (although close to zero) is that no organism can take N or P to zero. N and P were at concentrations at which the productivity of the bacteria becomes zero. Bacterial productivity follows a curve, with productivity getting less and less as nutrients get less and less, until a point is reached at which productivity is zero, but nutrients will not be at zero - although they will measure zero on our test kits. I don't see whats so difficult to understand. I think you have only read the abstract of that paper probably, if you read it all it might become clearer.

And another question, if limited N and P can not be removed by bacteria in the ocean (oligotrophic location!!!), how can it be removed in the tank, where we know the proportions of N and P are way higher?

I dont really understand what youre saying. Bacteria prefer higher levels of N and P and so will thrive in a high N and P tank fed carbon. Thats what we see when we dose carbon, so much so that we can experience bacerial blooms even.

Another related question: if DOC is not zero (in our reef tanks), why would you dose carbon? Wouldn't bacteria remove all C since N and P is available?

As Randy said already, carbon comes in different forms. As he pointed out to me a day or two ago, even different foods have different availabilities and energy per carbon atom. Think of it like this. If you were fed straw, despite its high carbon content, you would not gain much if any energy from it, but fed the same number of carbon atoms of sugar, you will be able to use it for energy. The same with bacteria. You might have plenty of organic carbon in the tank but if its not in a form that our friendly bacteria can use for energy, it wont feed them and N and P will not be depleted. And the organic level will stay the same. The idea with carbon dosing is to make sure the bacteria are fed a constant supply of suitable organic carbon.

 

[UK_Pete]

@Robf,

Regarding zeovit, my personal theory since I am a 'non believer' that it is simply magic stones, is just that its an optimized carbon dosed system, perhaps with some quirks. I am wonder about the potential for iron leaching from zeolite to reduce phosphate, I think that the high flow zeovit reactor makes a perfect carbon dosing ammonia reactor (IE a place for bacteria to grow, with high flow so rapid tank turnover and high oxygen from the rapid flow of oxygenated water, perfect conditions for direct bacterial conversion of ammonia to biomass), perhaps with iron supplementation coming from the zeolite for the bacteria too which are known to have a substantial iron demand. The zeovit system includes the use of heavy metals, the reason for which seems likely to be for controlled bleaching of corals. If iron levels are truely high then iron has been suggested to be able to bleach corals too. Manganese, an essential plant trace element always depleted to zero in triton tests when people publish results, also seems to probably leach from the zeolite. The zeovit reactor shaking daily, with its release of chunks of biomass, seems like an ideal way to feed corals, live food, which will not degrade fast, and I think perhaps that is a really great idea that I would like to implement myself, with or without zeolite. I also suspect that some, maybe many, zeo systems dont feed that much food from external sources with a fair bit being generated in tank (by recycling that is).

But all that is my speculation and zeovit users say we who have never used zeovit have no place to comment on the system, so I would not want my opinions to be thought of as anything other than speculation (which I would like, one day, to test - I have an idea about getting a couple of dozen other people like me curious about it together, and having all the products tested by triton or similar, so we at least have some science to go on when we speculate).

As for carbon dosing, I dont think there is a point at which a tank can no longer recycle nutrients unless for instance something toxic builds up. And there is no mention of that effect in the papers I have read so far regarding using this technique in aquaculture of shrimp and fish. Biomass can build up in some of these systems to tens of millions of cells per ml, or even higher IIRC, and at some point shrimp farmers found that shrimp mortality increased, IIRC because of clogging gills by the flocs of bacteria, which reduced flow in the gills. These papers suggest though that biomass can increase to very high levels, far higher than I would think we want in our tanks, which is where skimming and GAC come in IMO. Skimming is also probably vital to remove the high amount of CO2 produced by carbon dosing and add oxygen (once again, skimming and GAC are said to be vital for zeo, I think these reasons are good candidates for why).

Re crashing, it depends what you mean. One thing I like about bare bottom carbon dosing against sand bottoms is that little seems to build up, just the biomass you are currently working with so to speak. I dont think there is the potential for a crash as we know it with a sand bed because little is stored in the biomass in the tank, if you work out the weight of bacteria in a typical system and work out the nutrients present there are little in terms of ppm (although greater than you want to run with long term). With a sand bed carbon dosed system I think the potential for crashing is probably about the same, as I dont see the carbon dosing affecting the sand bed that much (although that view might easily be wrong, as the potential is there for the carbon dosed to the water to diffuse to the sand bed).

If you mean the bacterial population you had built up in the tank was to crash, an unlikely scenario IMO since the heterotrophs are tough and so rapidly multiplying, you would release some N and P, although I dont think much, but you might release significant carbon, if you could trigger all the bacteria to die somehow at once (like a large tank temperature excursion). This carbon would create excess CO2 and deplete oxygen as another bacterial population took off and used the carbon, N and P now in the system to build new biomass. But I cant really think of a common reason why one bacterial population would all suddenly die and another population suddenly took off, as these bacteria are aggressively trying to grow all the time until something limits them.

I do think though that one risk with carbon dosed systems is if you have a build up of some excess carbon (like vinegar, this would seem to be a normal situation perhaps in our tanks if we are dosing excess carbon according to Randy), and your tank is limited by N and or P, then if you have a sudden addition of N and or P such that your bacteria can bloom, your oxygen demand would shoot up, CO2 production shoot up and hence pH shoot down. How much risk that is in the real world I dont know as I am only theorising really there. And if you suddenly stop dosing carbon, your population will probably gradually die back, releasing nutrients gradually into the water, as they can apparently exist in a non growing state for considerable time from what I have read. It might take a long time for them to die in fact, and it might be more likely for them to be skimmed and removed with GAC before they do die, as they are evolved to exist in nutrient poor conditions ready and waiting for a nutrient surge to allow rapid growth.

So the way I see it is this. You add food in the form of blended fish / clam / squid mix (for instance). The food is mostly eaten by fish and perhaps corals if there is a fine fraction of particles. The eaten food is digested and some of the nitrogen in it is excreted, the rest is used by the organism to build its body mass up. The excreted nitrogen is used by bacteria, which need some of your dosed carbon too, and together the nutrients released as waste from the fish (or other food consumers) together with the dosed carbon allow the bacteria to build biomass. The biomass is resistant to being broken down to nitrate and phosphate in the tank water, which I personally think is a key, useful, feature.

Then the biomass can be eaten by a fish, or a coral, or perhaps a shrimp in your refugium. The biomass goes back into the cycle as food - part of the nitrogen in it is turned by the organism that eats it into body mass, part is excreted, converted from biomass into ammonia nitrogen again, and the excreted nitrogen once again needs more carbon to 'upgrade' it to biomass again. The nitrogen is recycled in every smaller amounts each time, and most of the carbon demand is generated by the first few cycles. I found a few figures for how efficiently fish can incorporate nitrogen eaten in the form of food, into their body mass, and it seems to be around 20 to 50% (depending on species). If you take the middle of that, 35%, and do a little calculation, you find that you need to dose about twice the 'theoretical ratio' of food : carbon as put forward in one particular paper I read (link can be found in my post about food to carbon ratios in the main forum).

Interestingly in the thread I started that only, unfortunately, attracted a couple of people to post their numbers, the 2 people who did post said they dosed very roughly 2.5 times as much carbon as that theoretical amount. The number of respondants was far too small to make any theories from that, but it does seem consistant with the numbers suggested by the maths above.

It would all seem to fit together and make sense. Any nutrients you add to the tank will eventually become living creatures of some type as long as you are adding carbon. Carbon is the energy source for the entire food chain in the tank, that which is generated in tank anyway, and if you have enough, then your nutrients will drop to very low levels and become limiting. If you are limited instead on carbon, your nutrients will rise unless something else is removing them. Bacteria floating around in a healthy tank will eventually be skimmed, absorbed on GAC or eaten by something - potentially fish (if the bacteria is a floc or clump), but certainly shrimp, filter feeders, and perhaps corals (I do believe this myself but am no expert in what foods different corals eat). In the ocean, carbon comes from phytoplankton according to the above paper, but that might only be looking at one corner of the oceans food chain. But I think the principle remains, the sun fuels photosynthesis, which allows algaes to produce organic carbon in the form of carbohydrates, which bacteria consume. The energy path is sun -> algae -> animal kingdom, including bacteria. I guess one could say ideally the aquarium lights would fuel the cycle of photosynthesis in our tanks and fuel phytoplankton but it might be that that process is inefficient in terms of space and our tanks need more carbon than they could generate themselves. But certainly adding organic carbon works to keep bacteria working hard at eating nutrients in our tanks, and without carbon dosing, I have not seen reports of BB tanks that generate enough carbon themselves to keep nutrients down themselves.

Anyway I have to stop typing sometime, I think I better stop at that!

 

[robf]

Thanks. That helps me a bit. I mistakenly thought you were suggesting simple carbon dosing was less ideal than zeovit (carbon dosing) methods. Sounds like they both have trade offs. I like the notion you can engineer or select from nature absorbents and catalysts to remove or create nutrients in a reef tank. This was my initial reason for going with zeovit. I certainly don't have the background you or Randy have so it's pretty challenging to try to make wise decisions in this hobby. My success or failure will no doubt have far more to do with my ability to create a stable environment for my sps than it whether I choose to carbon dose liquids, bio pellets or zeovit. Also, not having a background with organic chemistry or oceanography makes me biased toward known successes as opposed to custom designed systems. There is an awful lot of snake oil in this hobby and more than a few bandwagons to jump on. I've enjoyed the discussions. We've detoured a bit off the original topic of venturi skimming and potassium but there really is so much more to it than what means we employ to make our bubbles.

 

[UK_Pete]

First, I must say that Randy is the biochemist here and in no way me, although I have a scientific education it was in physics not biology or biochemistry. And physics is not that much use in the biochemistry of the oceans. I think the scientific background does make it easier to read relevant papers and studies so its useful. I dont think my opinions should be thought of as any other than those of an ordinary hobbiest and certainly not those of the highly trained contributors to the hobby like Randy and a few others we have in the field. I hope to fuel some more discussion so that in time we can verify or otherwise the points I brought up above, but not that what I say should be taken as if it was from Randy for instance.

I do think there might be more to zeovit than simple carbon dosing, but I am not convinced that the stones really have that much magic to them. Everyone who would know says there is no way the stones can work as the manufacturers suggest. I wonder if the manufacturers know themselves. They seem to imply that ammonia is bound to the zeolite and then this allows some type of bacteria (unspecified type I believe) to use the ammonia more efficiently, but everyone who I would expect to know says this is impossible. Reading up on the ammonia heterotrophs it seems they dont really need the zeovit to do this - they would do it on their own anyway, and the stones would provide good surface area, and the flow would create ideal oxygen and nutrient conditions. But maybe the iron and manganese in the stones helps supply essential trace elements directly to the bacteria living on the stones for instance. Maybe also the leached iron binds phosphate as dosing liquid iron does.

But then we have the imo pure genius of the stirred / shaken reactor, breaking up the biomass daily and feeding clumps of it back to the tank. This seems to me the perfect arrangement. I'm not sure if you can say this is 'pure zeovit' in a 'simple carbon dosing vs zeovit' comparison, in a way this is not 'simple carbon dosing' so in that case my opinion would be that zeovit is better in a way. But, I dont believe you need to pay for the zeovit products to gain this benefit.

I don't really believe the things like zeostart are that unique for instance. Its clearly a carbon source, they have mixed a few things, by the looks of things ethanol, vinegar and some acetates perhaps, so they can increase the concentration. Most of the other supplements seem to be heavy metal combinations, which could easily be investigated with a triton test. And then theres a few amino acid mixes, which I dont know much about - perhaps zeo have come up with some good ones.

I would like to try a zeo style reactor with some IE ceramic media or something (I wont be the first to try it). And add the trace elements that zeolite rocks would add using a doser and liquid trace elements (iron, manganese).

I know what you mean about wanting an system out of the box, and I think that sounds like a fair plan. I am quite a tinkerer and like trying to work out why, which probably is what drives my approach

 

[Diesel]

First, I must say that Randy is the biochemist here and in no way me, although I have a scientific education it was in physics not biology or biochemistry. And physics is not that much use in the biochemistry of the oceans. I think the scientific background does make it easier to read relevant papers and studies so its useful. I dont think my opinions should be thought of as any other than those of an ordinary hobbiest and certainly not those of the highly trained contributors to the hobby like Randy and a few others we have in the field. I hope to fuel some more discussion so that in time we can verify or otherwise the points I brought up above, but not that what I say should be taken as if it was from Randy for instance.

I do think there might be more to zeovit than simple carbon dosing, but I am not convinced that the stones really have that much magic to them. Everyone who would know says there is no way the stones can work as the manufacturers suggest. I wonder if the manufacturers know themselves. They seem to imply that ammonia is bound to the zeolite and then this allows some type of bacteria (unspecified type I believe) to use the ammonia more efficiently, but everyone who I would expect to know says this is impossible. Reading up on the ammonia heterotrophs it seems they dont really need the zeovit to do this - they would do it on their own anyway, and the stones would provide good surface area, and the flow would create ideal oxygen and nutrient conditions. But maybe the iron and manganese in the stones helps supply essential trace elements directly to the bacteria living on the stones for instance. Maybe also the leached iron binds phosphate as dosing liquid iron does.

But then we have the imo pure genius of the stirred / shaken reactor, breaking up the biomass daily and feeding clumps of it back to the tank. This seems to me the perfect arrangement. I'm not sure if you can say this is 'pure zeovit' in a 'simple carbon dosing vs zeovit' comparison, in a way this is not 'simple carbon dosing' so in that case my opinion would be that zeovit is better in a way. But, I dont believe you need to pay for the zeovit products to gain this benefit.

I don't really believe the things like zeostart are that unique for instance. Its clearly a carbon source, they have mixed a few things, by the looks of things ethanol, vinegar and some acetates perhaps, so they can increase the concentration. Most of the other supplements seem to be heavy metal combinations, which could easily be investigated with a triton test. And then theres a few amino acid mixes, which I dont know much about - perhaps zeo have come up with some good ones.

I would like to try a zeo style reactor with some IE ceramic media or something (I wont be the first to try it). And add the trace elements that zeolite rocks would add using a doser and liquid trace elements (iron, manganese).

I know what you mean about wanting an system out of the box, and I think that sounds like a fair plan. I am quite a tinkerer and like trying to work out why, which probably is what drives my approach

Thanks Pete,
So if we break this down, the ZEOlite stones can be replaced in the shaker/tumbler for 1" give and take liverock?
That would have the same effect as it holds bacteria as good as anything else.
The replacement of the ZEOlite is only based than on no more metals will be dosed into the tank by the shaker/tumbler, right?
Zeo advices on their behalf you have to replace the stones every 6 weeks give and take and with the auto Vibe about 8 weeks.
By replacing it with just LR you just can dose into your tank the metals that would come off the ZEOlite stones in order to have a ZEO look on your corals.
More like a Triton system

 

[robf]

Can someone expand on why the zeolites are replaced every 6 weeks? Im curious. How would one even know they were in need of replacement? Why would they need to be replaced if they were simply harbors of bacteria? Brightwell also has a zeolite media and I believe its quite a bit less expensive. KZ warns users not to just use any zeolites at some could cause problems. I've heard the ones used in freshwater for instance uptake calcium.

 

[jedimasterben]

The purpose of the particular zeolith stones used in Zeovit is to adsorb ammonia, locking it up and basically skipping the nitrogen cycle to help create a low nutrient environment. Bacteria realize this and make their films on the stones and will cleave the ammonia out, shaking the stones loosens some of the bacterial films so that not all of the ammonia is removed and released back into the system. That's my understanding of it, anyway.

 

[UK_Pete]

Well remember this is just an opinion for experimenting and discussing

I think the zeo system probably combines 2 or 3 aspects of water chemistry and coral keeping. I think first they almost certainly use metals like copper to induce controlled bleaching. There is substantial evidence of this from people who have tested for example zeospur and found it contained extremely high copper levels. The manufacturers IIRC responded that this product and others did contain combinations of metals which we would call 'heavy metals' and which we know to bleach corals at doses most of us would consider toxic, like 150 ppb copper in the tank IIRC. Also the stones, when replaced, are said to increased coral color, and since they are thought by many to release some of the iron in them, and iron is known to bleach corals too, thats another bleaching factor that might be significant. Or perhaps its the release of iron at peak levels from the fresh stones that deplete phosphate and work that way to increase colors. I do believe the stones leach some iron, having asked Randy about it recently, and he felt its certainly possible. Theres Habib of saliferts tests which demonstrated iron leaching, and there is other material available which suggests that iron and manganese do leach from zeolites. And fresh stones are certain IMO to release fastest with an 'early peak' effect, initially (or after a few days) releasing most, depending on the exact mechanism (biological / chemical).

It seems to be generally accepted that controlled bleaching can increase the vibrancy of coral colors so to me that all seems to fit into a fairly likely theory to explain part of the aspect of the zeo colors.

Also dissolved iron is able to bind phosphate and make it into a form that could be skimmable. Glenn uses this extensively in his DSR method, and iron formulations are available sold to control phosphate. The iron / iron phosphate would probably form a fine precipitate that it seems likely could be skimmed, and if the iron is released on the zeo stones, making a high concentration of iron in the slime that forms on the stones (the mulm), which might attract phosphate directly to the iron in the slime, which might be skimmed too, then that might increase that effect IMO.

And then theres the carbon dosing. Little to be said about that, we all know it works, although as I said earlier I believe the influence of carbon might be more complex than we usually hear about - ie the simple equation of bacteria eat nutrients and are skimmed. I think the coral food aspect and the recycling aspect might be important too. The GAC used in zeo systems might be very important to this as skimming has been shown to maybe not be that effective at skimming these bacteria while GAC seemed more effective. I find it hard to believe that the zeo organic carbon sources are that different to the non zeo ones we use, and since Randy and other highly regarded experts believe that, I think its a fairly safe bet that its true.

And then theres the trace elements, iron and manganese, which seem to be present in most zeolites and which might be significant for coral health. I noticed recently while browsing the tritton test thread that not one person IIRC had measurable manganese in their tank water, while all salts contained IIRC 2 ppb. Randy mentioned manganese in one of his articles as a possible important trace element, and I know that in plant nutrition, its considered a vital element required in significant amounts.

Another aspect I have noticed is that with flow going through media with biofilm on it, the biofilm seems to be sticky and to attract particles if the flow rate is right. Zeo state that flow rate through their reactor is important to get right - not too high, not too low, which once again makes me feel this might be a useful effect. The rate of flow across media covered with heterotrophic ammonia consuming bacteria would be important because at too high a flow, the biofilm would be continually washed off, preventing it building up enough to shake clumps off daily, and too low a flow, the turnover of tank water though the 'ammonia filter' (the zeo reactor) would be too low to keep ammonia low. Fairly high flow means high amounts of oxygen getting to the bacteria and they need lots of oxygen. At the 'right' flow rate, bacteria in the water might stick to the biofilm and be removed from the water, building up the thickness of the biofilm on the media, only to be shaken off daily in clumps back into the water. But the fact that the bacteria have now been stuck together in clumps might be positive for allowing corals to capture the clumps better than they capture individual bacteria. The cycle repeats daily with the clumps being pumped back to the zeo reactor, being collected by it, and shaken off again the next day.

So as you say, my plan is to dose the the trace elements (iron and manganese) rather than expect the media to provide them, and use inert media. How to work out how much manganese to dose I am not sure. Iron seems to be depleted rapidly so I think I can just blindly dose very low levels of that (IIRC I recently decided about 10 ppb a day). I plan to use a harder material than LR in a zeo reactor, maybe an artificial one, or maybe even zeolite but never replace it. I also plan smaller than 1 inch, maybe 0.5 to 0.75 inch - surface area is going to be affected by that. Not so fine a material that shaking it will not release mulm though, there needs to be large enough channels between the rocks. At this time I have no plan to use heavy metals to increase colors though, I just want the heterotrophic bacteria reactor for low ammonia, and for its mulm food source.

So in summary, IMO the zeolite in zeo and similar systems is not doing anything related to zeolites ammonia capturing abilities in freshwater, too many people like Randy have said there is no scientific explanation for that currently at least. Zeo and similar are probably benefiting from the high flow ammonia reactor which utilises heterotrophic ammonia consuming bacteria and dosed carbon, which keeps ammonia and all forms of inorganic nitrogen very low, and probably phosphate too is reduced significantly by the bacteria. The media provides a good surface as you say. Shaking it daily seems likely to be a great food source, and the 'uneaten' food does not die and create waste, because its still alive, it just gets captured by the zeo reactor within a few minutes and is stored, alive, ready for tomorrows shaking of the reactor. I do believe that in a system that nutrients are kept very low, other sources of food are probably vital, so the mulm or perhaps the individual bacteria in the water are perhaps very important.

I am curious about the amount of iron released, whether it directly controls phosphate by chemically bonding to the phosphate and getting skimmed, or whether the phosphate control is entirely biological. I suspect a bit of both. Iron attracts any excess of phosphate which builds up, and which the bacteria don't get to first. And finally the leached iron and manganese might be useful both for corals and bacteria for nutrition, as bacteria have been shown to be limited by iron sometimes in oceanic waters, so keeping a supply of it in the water seems likely beneficial. Certainly iron, and perhaps both these elements are rapidly removed by chemical processes in seawater. In addition I think zeo uses heavy metals to carefully bleach corals. And as for their amino products I don't know, maybe they are better than others products, thats something to find out in the future

I would be very interested to see some triton test results for zeo tanks, and might see if anyone has run triton tests on their tanks on the zeovit forum. I would be looking to see manganese and iron levels for starters. It would also be extremely interesting to see results posted at the peak of coral coloration just after changing stones, and then just before replacing the stones. If there was a difference in iron, manganese or anything else at these different times, it could add some validity to all this wild speculation!

 

[UK_Pete]

Rob / Jedi,

Its an interesting question. I don't think the zeo manufacturers actually say they believe the zeolite is chemically removing the ammonia, but I think they do say that the zeolite aids the bacteria by increasing its concentration on the stones, where bacteria are able to gain access to higher concentrations. Problem is, I have not seen any people who actually understand this process agree that its possible. Randy for instance is quite dubious of it, there are threads on the web where people have discussed this for several tens of pages, and there is not a single bit of conclusive evidence. Which is what makes me so curious about it, I don't like mysteries.

Despite saying that the stones do not permanently take the ammonia out, so can not become 'full' of ammonia, the manufacturers say the stones need to be replaced because they become mechanically clogged with bacteria. I find that hard to accept as a sound theory myself though. Why 6 weeks? Why not remove the bacteria with NaOH? Coupled with the info about zeolites leaching iron, I find it easier to accept that the iron is the reason the stones need replacing (I did not come up with this theory myself - others have been thinking this for years). The iron is becoming depleted in the stones and they are leaching less. Iron dosed to a tank will drop phosphates very effectively. Carbon dosed tanks do not always have iron under full control and some use GFO for instance as extra phosphate control. Glenn uses iron citrate to control excess phosphate in his tank. If the iron leached from the older stones drops, and the iron is removing phosphate, then phosphates will creep up, and corals will lose color. Put fresh stones in, with a full dose of iron now going in, phosphates will quickly drop, and corals will gain extra color is the theory.

As I said above I dont see the need for a stone to remove ammonia in a carbon dosed system. The heterotrophs are so aggressive at removing ammonia themselves, I dont see them needing any help from what I know. Even less from a zeolite stone which is said to be covered with a thick bacterial slime, I cant see ammonia diffusing through this, escaping the bacteria in the slime which are eager to assimilate all the ammonia they can, and reaching the zeolite internal pores, only to go back out again to the bacteria at some unspecified time. It just does not make sense to me!

If you drop any old zeolite in a tank, I understand that many will take calcium and potassium out IIRC. So maybe the manufacturers of zeo preload their zeolites with these elements to reduce their depletion in tanks when the stones are put in a tank.

 

[Randy Holmes-Farley]

Its an interesting question. I don't think the zeo manufacturers actually say they believe the zeolite is chemically removing the ammonia, but I think they do say that the zeolite aids the bacteria by increasing its concentration on the stones, where bacteria are able to gain access to higher concentrations. Problem is, I have not seen any people who actually understand this process agree that its possible. Randy for instance is quite dubious of it, there are threads on the web where people have discussed this for several tens of pages, and there is not a single bit of conclusive evidence. Which is what makes me so curious about it, I don't like mysteries. .

Right, that makes no sense to me.

 

[Diesel]

Ok, I do the full ZEO system on my tank and with some Triton test done they came back with a elevated Copper and Aluminum level.
Corals look good though but I'm just wondering if I walk the edge here?
With maybe one or two bad bags of ZEOlite stone I can be in the danger zone, maybe?
Just wondering, if there's no theory about the stone from ZEO working other than it is just a bacteria factory which isn't that bad of course but leaching out metals in the water column to on a controlled schedule bleach corals I can maybe replace the ZEOlite stones for something like another Biological Filtration Media like
MarinePure Ceramic Biomedia Balls.
Still doing the doses for ZEO but just not the stones, I know this will be a try-out and see if it works.
Of course why do ZEO if you don't go full blown........... well, isn't this hobby build on most part trying out what works best as each system can be different.
Thought I throw my $0.02 on the table.

 

[wangspeed]

If you are full zeo, you probably already know that Zeospur needs to be done EXTREMELY carefully. It has copper in it to help purge brown zoox and bring out colors.

 

[UK_Pete]

I guess its possible that an unlucky bag of zeo stones have a much higher amount of iron near the surface of the stone where it could leach fast. On the other hand its not proven that the zeo stones leach significant iron to the water, its just that there is quite a bit of evidence that they might. High iron would also not stay in the water long as it precipitates fast, unless it is in chelated form (bound by organics). Even when chelated with a fairly weak chelator, citrate, it breaks down in the water and is precipitated in hours according to Glenn. He doses IIRC 0.25 ppm iron to reduce phosphate and 6 hours later finds his levels are 0.01 ppm iron I believe (but check his threads on the subject if you want to be sure of those numbers).

So one thing I am interested in is how much iron the stones do leach, and how they leach the iron - I asked Randy about this recently and he essentially said its hard to be sure. Its possible that bacterial action chelates iron from the stones, and its possible that a reducing environment in the stones caused by different bacteria might release iron too. But looking yesterday at a couple of zeo triton tests, the iron measured below detection, meaning less than 0.3 ppb. So if that result is common to most zeo tanks, that would suggest that iron is not acting to bleach corals directly, if Glenn doses 0.25 ppm (almost 1000 times more) and sees no bleaching. It does not mean that the stones are not leaching though, as they might be slowly leaching iron which quickly precipitates (maybe taking phosphate with it). It would still be interesting to see a triton test of zeo water a few days after adding new stones, when the corals are seen to reach peak color, to check iron levels at that point.

If you are an experimenter (as am I), I think theres a few things worth trying. For one, do you see this 'coral color up' when you change stones? If so, perhaps you could try just leaving the old stones in past their 'change by' date, and then try dosing a small amount of a few supplements that might be expected to be in the new stones. Iron and manganese are the 2 that come to mind. Manganese is very cheap and easy to get on ebay - its an essential element for plant nutrition and you can get it as manganese sulphate (I have a little 50 gram pack I got for my tomatoes). You can use Randys new iron gluconate DIY for the iron using IIRC fergon tablets sold at the pharmacy, or make his old iron citrate supplement with ferrous sulphate and tri sodium citrate - both from ebay for a dollar or two for a small pack. The manganese would need to be dosed very low I think, and since Glenn doses iron to 0.25 ppm safely, I think you can probably start with say 10 times less that that and build up to that dose. If you were to see the color up effect on the corals, that would seem to suggest that indeed the stones are leaching those elements. If you see nothing, you can always stop after a few days and just put new stones in.

I plan to try the zeo reactor thing with inert media like you mentioned but you are in an ideal spot if you are already running zeo to see if some careful dosing of supplements replicate the effect of new stones. Do let us know if you try this! It will be great to see a report of it. And if you want any help work out weights to mix up stock solutions etc, PM me or post etc, I would be happy to help if I can.

BTW re the elevated aluminium and copper, what zeo supplements do you dose and what were your levels?