This site is supported by the advertisements on it, please disable your AdBlocker so we can continue to provide you with the quality content you expect.
  1. We are after as many aquarium plant images that we can get, doing so will assist us in completing the aquarium plant database.

    https://barrreport.com/threads/aquatic-plant-images-wanted.14374/
    Dismiss Notice

Nh4 Vs No3 Uptake Study Conflicts

Discussion in 'Aquatic Plant Fertilization' started by Deanna, Aug 23, 2018.

  1. Deanna

    Deanna Member

    Joined:
    Aug 23, 2018
    Messages:
    53
    Likes Received:
    28
    Local Time:
    11:18 AM
    I want to collect some opinions from ‘Barr-isters’, here, regarding N uptake theories.

    I have long accepted the 2005 “Nitrogen Cycling in Planted Aquariums” article by T. Barr as valid. As there seems to be nothing on this forum that supersedes it, I assume that both T. Barr and the members continue to believe that it is valid. The particular aspect of it, for this posting, that interests me is the position on NH4.

    The article/study maintains that, at <.5 ppm NH4, plants will prefer NO3 due to the ‘training’ of the enzyme designed for NO3, but the NH4 enzyme (along with our BB) will still soak up the little bit of NH4 as it is created. This assumes a healthy biomass. Of course, in a high tech tank during lights on, our CO2 is going to drive pH below 7, assuring that all NH3 is converted to NH4. If this is true, my thinking is that we should try to exploit this NH4 reduction activity by keeping BB active (oxygenation and pH levels above 6.0).

    However, there is a conflicting article offered by D Walstad titled: “Plants versus Filters" for which I can no longer find a valid link (but have a copy if anyone is interested). It is dated July 2014. In it, she contradicts the NH4 study regarding NH4 uptake, stating that plants will prefer, and access, all the NH4 available and would rather ignore NO3. Although she runs low tech tanks, I doubt that the N uptake mechanisms would be different in a high tech tank. I have run my tank without bio-media in my filter for several years on this basis and have been successful (obviously,sufficient BB in the substrate and other surfaces).

    I am now, for various reasons, considering shifting to T. Barr’s approach in the article. I would like to collect opinions as to what members, here, believe to be the better approach and, if there is a reason, what is it? Is it possible that the Walstad references in the article are more recent and supersede the T. Barr 2005 data?
     
  2. Phishless

    Phishless Lifetime Member
    Lifetime Member

    Joined:
    Jul 13, 2017
    Messages:
    1,116
    Likes Received:
    969
    Local Time:
    11:18 AM
  3. Phishless

    Phishless Lifetime Member
    Lifetime Member

    Joined:
    Jul 13, 2017
    Messages:
    1,116
    Likes Received:
    969
    Local Time:
    11:18 AM
    Many opinions will most likely be shared here?

    Having dosed urea daily while maintaining EI macro levels I cannot say anything was growing better. :(
    Algae is easier to promote if NH4 levels are not watched closely, risk factor for some.
    Dosing of compounds(ferts) seems to far out way phish produced waste when it come to premium plant growth. :D

    Having read her book(2x), cannot speak good nor bad regarding Diana's writings.
    We are @ two different extremes of the hobby. o_O

    Tom does mention in the article about "trying" different approaches and we all know that no two tanks are alike.
     
  4. Deanna

    Deanna Member

    Joined:
    Aug 23, 2018
    Messages:
    53
    Likes Received:
    28
    Local Time:
    11:18 AM
    So, it sounds like you are falling on the side of Tom's 2005 study. I've watched many people try the urea/nh4 dosing approach on TPT with the same results as you. I also tried it with no better results.

    No question about variability in tanks, but the N uptake mechanisms shouldn't vary. Hopefully, others will chime in, as I am interested to hear if that 2005 Barr study is the current thinking here or if the data in the Walstad 2014 study, being more recent, is the predominant thinking.
     
    tiger15 likes this.
  5. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,693
    Likes Received:
    725
    Local Time:
    4:18 PM
    I've found no issues either way with urea vs NO3.
    Urea seems to get away from some and they kill or roast their plants, get algae.
    But only if they lard it on.

    NH4 binds to soil, NO3 does not, so you will see a much better response if you use soil with NH4, vs plain inert soil or ADA like soils with low NH4.
    Something like this:

    But both in the water really does not seem to help.

    Fish waste etc...........I think there's a bacterial linkage that can help plants and the tank overall, hard to say though.

    uptakeofNincorn_zpsj8wd0cxl.jpg
     
    Phishless likes this.
  6. Deanna

    Deanna Member

    Joined:
    Aug 23, 2018
    Messages:
    53
    Likes Received:
    28
    Local Time:
    11:18 AM
    Thanks, Tom. However, my interest, in the OP, is not about urea. That was raised somewhat off-topic. The only aspect of that was that we found no difference between dosing it and other forms of N.

    My main interest to determine if you still support your 2005 “Nitrogen Cycling in Planted Aquariums” article. As I mentioned, D. Walstad entered a much more recent article that seems to be in a completely different camp. So, I’m wondering if more recent data/studies have altered your beliefs from that 2005 article.

    Further; you just threw a curve in that caught my eye. What do you mean by "bacterial linkage"?
     
  7. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,693
    Likes Received:
    725
    Local Time:
    4:18 PM
    Not really, plants have not significantly changed and if it was really a thing, at least enough to be a significant issue, we SHOULD be able to see it, and there should be some consensus among those who have some degree of mastery at growing aquatic plants.

    It also can be an issue of the species of plant in question, as aquarist we compare 20-50 species easily pretty quick. Researchers rarely have more than 3-5 plant species to compare.
    Some might prefer NH4, others might prefer NO3.
    Others might prefer a mix or ratio(most fall into this group).

    Still, they did not address the location of the N, sediment vs fertilizer/water column.

    Some plants lack roots, eg, Riccia, whereas others have strong large root systems, Crypts and Swords, or finer roots like Rotala.
    Some plants might be poorly adapted for aquatic submersed light.
    Others do well, but are not found submersed in nature, eg, Ammannia gracilus.
    Anubias also rarely ever found submersed.

    The claim and the observations need to match at the most basic level.
     
  8. Tom Barr

    Tom Barr Founder
    Staff Member Administrator

    Joined:
    Jan 23, 2005
    Messages:
    18,693
    Likes Received:
    725
    Local Time:
    4:18 PM
    Also if you look at the graph in the article, NO3 is not taken up till the ppm for NH4 hits about 0.5ppm and then the NO3 really picks up.
    We really do not add that much NH4 and it;s hard to get any reading for NH4, NO3 is benign for the most part over a wide range, so adding that helps.
    NH4 0.8 ppm is equal to about 3-4 ppm of NO3 also due to those O atoms vs H.

    Simply add some fish and feed them.
    Add long term sources of NH4: soil
    Plants get plenty of NH4 that way.

    Also, if you are concerned about growth rate............well, add CO2 gas, add more light etc.
    I just do not see milking the NH4 will yield much to the hobbyists really.
    Algae is not factored in nor livestock in those examples in research.

    56 ppm of NH4? 2.0 ppm?
    Floating plant vs submersed plant?

    She clearly states however that fish waste can meet the N needs for plants in aquariums.
    So..............I see little issue.

    There's just not a lot of research done on the topic in wetland plants, aquatics etc.

    I tend to go with what we have seen over and over and over when we have dosed various nutrient and forms.
    If the user is good aquarist and a good grower, then severla folks all on the same page is fairly likely to have something.

    Also, over time and with several tanks, that adds up and provides support.

    If you dose NH4 to the water, or add to the soil(like the clays), vs say a jobes stick..........but jobe sticks work well for swords.
    So, just do not uproot too soon after adding.
     
  9. Deanna

    Deanna Member

    Joined:
    Aug 23, 2018
    Messages:
    53
    Likes Received:
    28
    Local Time:
    11:18 AM
    Yes, reading that article, I saw the same thing: between the plants and BB (particularly if we load the bio-media up in the filter), the NH4 should never exceed .5 and may not even come close to that. So, the article states that plants will ‘train’ that NO3 enzyme to prefer NO3 to NH4 when NH4 is scarce. I do have high light (~80-90 Par at the substrate) and inject CO2 (>1.5 pH drop from fully degassed).

    Why do healthy plants inhibit algae (rhetorical question)? It must be either allelopathy or starvation for NH3/NH4 (depending upon pH) …right? Maybe both, but I haven’t seen any strong evidence anywhere for allelopathy in hydroponics.

    So, I’m now inclined to follow your 2005 article over the 2014 one. I’m re-building my bio-media (was running without any in my filter). Although my algae issues are minor, I’m interested to see if the increased reduction in NH4/NH3 will dampen it even further.
     
Loading...

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice