Roan Art said:
Well it doesn't remove the nitrates but removes the nitrogenous organic waste. Still has to affect the nitrates in some way doesn't it?
Nitrates
- Thread starter graysilm
- Start date
Well it doesn't remove the nitrates but removes the nitrogenous organic waste. Still has to affect the nitrates in some way doesn't it?
Perhaps, but I think my plants suck it all up before the Purigen canIceH2O said:
I have to dose 30ppm every 3 days or it hits 0. Was like that before I added Purigen and hasn't changed.Wait, the tank I was cycling? I had Purigen in there from the very start and of course I was not dosing KNO3 during the cycle. About half as many plants as my Boe tank. It didn't affect my nitrate levels at all. Stayed between 5.0 and 15.0 on average the entire cycle. Spiked to 40ppm at one point. Bottomed at 0 twice.
So, no, I don't think Purigen does anything with nitrogenous organics, even if it says it does.
Roan
Purigen works on organics, not inorganics. Organic compounds can and do contain nitrogen (which is why it is a macronutrient for plants), and why you can cycle a tank with rotting shrimp. But organics are not a major contributor to dissolved nitrate in tanks unless you massively overfeed or leave lots of plant debris and/or dead fish to decay in the tank.
I did some coil denitrator trials. IMHO they are "fiddly" (reguire constant, chronic tiny adjustments to be effective) and if not tuned can wipe out a tank. NIMT, thanks anyway. Plenums work, veggie filters work, RO works.
I did some coil denitrator trials. IMHO they are "fiddly" (reguire constant, chronic tiny adjustments to be effective) and if not tuned can wipe out a tank. NIMT, thanks anyway. Plenums work, veggie filters work, RO works.
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RTR,RTR said:
Had no clue what the hey a "plenums" was, so was doing research to find out. Got side tracked and read something interesting that may be related to another thread:
"Bacteria in an O2 -free zone reduce nitrate back to ammonium, no further - the ammonification process or assimilatory denitrification (re-assembly of ammonium, i.e., ammonification).
Not only will the ammonium get back into the bulk water, the bacteria's inefficient use of phosphorous results in extra phosphate being produced. "
http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=21Not only will the ammonium get back into the bulk water, the bacteria's inefficient use of phosphorous results in extra phosphate being produced. "
If, for instance, someone has a pH crash and subsequently their tank recycles and produces large ammonia spikes, could/would this account for the tank becoming excessively heavy in phosphates?
Would this also account for the presence of brown diatoms after a tank is finished cycling, assuming that large quanitities of phosphates are available otherwise (ie from tap)?
That aside, I still don't know what "plenums" are
Back to the search!Roan
Plenums were developed and introduced by the Monaco aquarium quite some time back. Such consists of a "dead space" at the bottom of the tank, generally created by a sheet of eggcrate plastic covered with fiberglass mesh screening, supporting some depth of substrate of a fairly fine particle size.
Everyone is or should be familiar with the possibility of anoxic areas deep in the substrate, and if the subtrate has become enriched with organics over time, the posiblilty of dangerous gas production (H2S, methane, etc.) under profound anoxia. But fewer seem to be aware that under conditions of less deep anoxia* that nitrate is reduced to nitrite and on to ammonium and that on to ntirogen gas, mediated by bacteria just as the oxidation if ammonia of ammonia is done in high ORP situations (our filters). The bacteria (anaerobic to anoxic) are quite diffent, and the process is slower to establish (diffusion, not flow, is involved - a much slower process). But it does and can happen and can be used in SW (first use and where it was developed as a practical process), BW, or FW.
BTW, the quote cited was astonishing in its ignorance. There is nothing inherent or magic in a glass or acrylic box that forces full-natural processes to stop at some arbitrary stage. Ammonium certainly can and is routinely reduced to N2 gas in many hobby tanks (requiring only deep substrate) whether the tank operator is aware of it or not. It is absolutely astounding to me that some people think there some sort of magic involved in tank process involving biochemistry. We are a community of the biologically and biochemically naive, and as such seem prey to mind-boggling mythology. If the conditions are right for nitrate reduction, they are right for nitrite reduction, and for ammonium reduction. Phosphate handing is a separate issue, as is H2S or methane generation - separate condition requirements exist for each, which is why we can take and use the mildest (highest ORP) case (nitrate to N2) and use it if we wish. Additionally, if an energy source exists at some depth in the substrate, bacterial species which can utilize that source will colonize that area/depth/environment. We see that in our high-ORP biofilters. It may be slower than we would like, but it can and will happen. The movie tag "If you build it, he will come" can easily be applied to the microbial world - if a food source exists or develops, users of that source will come and will establish. Every region of NNR is capped by regions of users (oxidizers) on ammonium and nitrite. Certainly the intermediate products, nitrite or ammonium, diffuse from the area, but if they diffuse upward, they are consumed by the higher-ORP bacteria at that level, and thus recycle, just as they do in our aerobic biofilters. No magic is required or involved.
*Anoxia and or anaerobic conditions are not a single state, but a continuum. All substrates have a decrease in oxygenation with depth, controlled by the particle sizes in the substrate and by depth. Very fine particle substrates have a very steep decrease in ORP (oxidation-reduction potential) with increase in depth. Larger particle substrates have less steep declines. Below a tiny depth in either, diffusion becomes far more important than flow, and smaller particles hinder diffusion quite well - there are fewer and smaller more torturous channels than with larger particles. This is responsible for the risk of undisturbed small-particle substrates.
With sufficient depth, any particulate substrate will have levels of reduction in oxygenation with increases in depth. At some depth the environment will be appropriate for normal denitrification, the reduction of nitrite to nitrite to ammoniun to nitrogen gas (N2). Still deeper, the O2 tension/ORP will be still lower, and allow for sulfide and iron reduction, and even methane generation.
The brain at Monaco got the concept of controlling the depth of anoxia possible deep in a substrate by placing a plenum (literally a vacant space) under the substrate. Vacant spaces - water only - do not hinder diffusion at all. this would in theory block the deep anoxia (very low ORP) required for the nasties, but allow what came this side of the pond to be called NNR (normal nitrate reduction) but blocking methane, etc. production. It works.
Note: Undisturbed deep anoxia or moderate anoxia are neither harmful in and of them selves. Methane and H2S generated in very deep and fine substrates will be oxidized as they diffuse upward, as the overlying levels will be colonized by bacteria which can and will oxidize them. Ditto for nitite and ammonia from NNR areas. The danger is in and if they are disturbed by inhabitants or by the hobbyist. Then toxic material can be released, and the critter injury or death can follow.
HTH.
Everyone is or should be familiar with the possibility of anoxic areas deep in the substrate, and if the subtrate has become enriched with organics over time, the posiblilty of dangerous gas production (H2S, methane, etc.) under profound anoxia. But fewer seem to be aware that under conditions of less deep anoxia* that nitrate is reduced to nitrite and on to ammonium and that on to ntirogen gas, mediated by bacteria just as the oxidation if ammonia of ammonia is done in high ORP situations (our filters). The bacteria (anaerobic to anoxic) are quite diffent, and the process is slower to establish (diffusion, not flow, is involved - a much slower process). But it does and can happen and can be used in SW (first use and where it was developed as a practical process), BW, or FW.
BTW, the quote cited was astonishing in its ignorance. There is nothing inherent or magic in a glass or acrylic box that forces full-natural processes to stop at some arbitrary stage. Ammonium certainly can and is routinely reduced to N2 gas in many hobby tanks (requiring only deep substrate) whether the tank operator is aware of it or not. It is absolutely astounding to me that some people think there some sort of magic involved in tank process involving biochemistry. We are a community of the biologically and biochemically naive, and as such seem prey to mind-boggling mythology. If the conditions are right for nitrate reduction, they are right for nitrite reduction, and for ammonium reduction. Phosphate handing is a separate issue, as is H2S or methane generation - separate condition requirements exist for each, which is why we can take and use the mildest (highest ORP) case (nitrate to N2) and use it if we wish. Additionally, if an energy source exists at some depth in the substrate, bacterial species which can utilize that source will colonize that area/depth/environment. We see that in our high-ORP biofilters. It may be slower than we would like, but it can and will happen. The movie tag "If you build it, he will come" can easily be applied to the microbial world - if a food source exists or develops, users of that source will come and will establish. Every region of NNR is capped by regions of users (oxidizers) on ammonium and nitrite. Certainly the intermediate products, nitrite or ammonium, diffuse from the area, but if they diffuse upward, they are consumed by the higher-ORP bacteria at that level, and thus recycle, just as they do in our aerobic biofilters. No magic is required or involved.
*Anoxia and or anaerobic conditions are not a single state, but a continuum. All substrates have a decrease in oxygenation with depth, controlled by the particle sizes in the substrate and by depth. Very fine particle substrates have a very steep decrease in ORP (oxidation-reduction potential) with increase in depth. Larger particle substrates have less steep declines. Below a tiny depth in either, diffusion becomes far more important than flow, and smaller particles hinder diffusion quite well - there are fewer and smaller more torturous channels than with larger particles. This is responsible for the risk of undisturbed small-particle substrates.
With sufficient depth, any particulate substrate will have levels of reduction in oxygenation with increases in depth. At some depth the environment will be appropriate for normal denitrification, the reduction of nitrite to nitrite to ammoniun to nitrogen gas (N2). Still deeper, the O2 tension/ORP will be still lower, and allow for sulfide and iron reduction, and even methane generation.
The brain at Monaco got the concept of controlling the depth of anoxia possible deep in a substrate by placing a plenum (literally a vacant space) under the substrate. Vacant spaces - water only - do not hinder diffusion at all. this would in theory block the deep anoxia (very low ORP) required for the nasties, but allow what came this side of the pond to be called NNR (normal nitrate reduction) but blocking methane, etc. production. It works.
Note: Undisturbed deep anoxia or moderate anoxia are neither harmful in and of them selves. Methane and H2S generated in very deep and fine substrates will be oxidized as they diffuse upward, as the overlying levels will be colonized by bacteria which can and will oxidize them. Ditto for nitite and ammonia from NNR areas. The danger is in and if they are disturbed by inhabitants or by the hobbyist. Then toxic material can be released, and the critter injury or death can follow.
HTH.
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RTR does a plenum need an influx of oxygenated water.
I read that you use veggie filters but wondered about the denitrator.
I want to thank you about a disagreement you and I had about a month back. It prompted me to start reading again; something I don't do enough of. All my books are old and some of the data that I've taken as gospel for years I find incorrect. One of the things I'm changing is substrate heating per our discussion. I started a 125 gallon planted discus tank today and am going without substrate heating. Just finished the substrate this morning. Six hours of fluorite rinsing yesterday...sheesh. Thanks again.
Mark
I read that you use veggie filters but wondered about the denitrator.
I want to thank you about a disagreement you and I had about a month back. It prompted me to start reading again; something I don't do enough of. All my books are old and some of the data that I've taken as gospel for years I find incorrect. One of the things I'm changing is substrate heating per our discussion. I started a 125 gallon planted discus tank today and am going without substrate heating. Just finished the substrate this morning. Six hours of fluorite rinsing yesterday...sheesh. Thanks again.
Mark
Nope, no plenum water influx needed beyond what it gets through the substrate by diffusion. More flow and especially more O2 would be counter-productive and wipe out the anaerobic bacteria reducing nitrate. Then you would effectively have a very slow UG filter.
I've not used any coil denitrators on my display tanks, only run tests on them enough to find them unsatisfactory for me. My veggie filters are denitrators/limited demineralizers themselves.
I'm glad to help folks get up to speed, that is why I'm here. But that does not mean that the hobby will not continue changing constantly - the more we learn about semi-closed system management, the better we can get.
LOL on the Flourite rinsing! Been there, done that, had sore hands for days. Sometimes I've got to do an illustrated article on that - my current technique most folks find hysterical, but it does work. It involves a very large (restaurant/commercial) soup/stock strainer, customed buckets with side holes, the garden hose, and a sunny afternoon out on the driveway, with moderate weather . Totally impractical for any single tank, but when you run dozens it pays to simplify with what at first appears to be complications. :dance2:
I've not used any coil denitrators on my display tanks, only run tests on them enough to find them unsatisfactory for me. My veggie filters are denitrators/limited demineralizers themselves.
I'm glad to help folks get up to speed, that is why I'm here. But that does not mean that the hobby will not continue changing constantly - the more we learn about semi-closed system management, the better we can get.
LOL on the Flourite rinsing! Been there, done that, had sore hands for days. Sometimes I've got to do an illustrated article on that - my current technique most folks find hysterical, but it does work. It involves a very large (restaurant/commercial) soup/stock strainer, customed buckets with side holes, the garden hose, and a sunny afternoon out on the driveway, with moderate weather . Totally impractical for any single tank, but when you run dozens it pays to simplify with what at first appears to be complications. :dance2:
Thanks for the explanations, RTR!
It's hard to get info for something you've no clue about -- no idea who's out to lunch and who isn't. Getting an idea of WHAT to look for helps weed through the garbage.
Thanks again,
Roan
It's hard to get info for something you've no clue about -- no idea who's out to lunch and who isn't. Getting an idea of WHAT to look for helps weed through the garbage.
Thanks again,
Roan
RA - there is a lot on NNR and/or plenums on the web, if fact, looking for such info was why I came over into the aquarium hobby part of the web initially, many moons ago - and as is usual for the web, much info is garbage, misunderstood, or misrepresented. But there is some decent stuff around. Most info is SW, and many folks have moved on to DSB there, but I distrust that practice myself. Any experimentation with either format might be best done first using a sump with the plenum or DSB located there - bigger safety factor. For myself I have largely moved on to refugia separate from the display, for ease of management and freedom from disturbances.
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