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EI dosing

Discussion in 'CO2 Enrichment' started by laka, Dec 5, 2008.

  1. laka

    laka Prolific Poster

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    I do not understand why ferts are dosed in excess? Sure you say to avoid any possible deficiency. Let's look at one nutrient. Nitrate. In Tom's article, the maximum possible uptake of nitrate in a high light/CO2 tank is 1-4ppm. So why dose the recommended levels of 10-30ppm? The only explanation i see is plant mass. The more dense a tank set up, the quicker the plants may run into deficiency. So to avoid regular testing, one overdoses the tank to ensure nutrients do not run low. Is this correct?

    What about the alternative of running the tanks lean ie. based on max. nutrient plant uptake, test weekly to confirm these levels are within this range ie. PPS.

    LAKA
     
  2. ceg4048

    ceg4048 Lifetime Charter Member
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    Hi,
    The first number range you list is a daily uptake rate and the second number range you list is a weekly dosing rate. Multiply the first set of numbers by 7 (days per week) and you will see they are very close.

    Hobby grade test kits are notoriously unreliable and the uptake rates are not always consistent. So the test results are more often than not totally corrupt. To counter these inaccuracies many resort to calibrating their kits by concocting elaborate reference solutions and perhaps plotting a series of test results on a graph to determine compensation factors. This adds yet another layer of unnecessary complication.

    Additionally, test kits cost money that would be better spent elsewhere, like buying more plants or cool new equipment - or even more beer. One can find more accurate kits on the market but these cost 10X what the basic kits cost, so very little advantage there. Many also feel that testing is irreconcilably tedious and a complete waste of time. The simple reason is this: If you dose the EI values then you already know absolutely what levels are being introduced into the tank, therefore test kits don't tell you any more than you already know. Excess nutrients don't cause algae and are not toxic to fauna. Insufficient nutrients however, do result in a tremendous amount of algae. This is a fact that many people struggle with and have trouble believing simply because the world at large has programmed them to associate nutrients with Armageddon so they have trouble letting go of this notion. As a result they suffer subconscious urges to test.

    It's therefore completely logical to dose excess in order to ensure that you do not fall below the minimum required levels without ever having to test - and without incurring any penalties as associated with having that excess.

    Now, if testing gives you a thrill then by all means test, but one of the main principles of EI is the freedom of not having to test, so it's utterly pointless to introduce testing to a scheme specifically designed to eliminate the need for testing.

    Cheers,
     
  3. rich815

    rich815 Guru Class Expert

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    >>>>test weekly to confirm these levels are within this range ie. PPS

    Exactly so you do NOT have to do that.
     
  4. Tom Barr

    Tom Barr Founder
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    These are all good questions and ones I and others have heard and asked in the past.

    There are few things going on here.
    1st,
    The word "excess" is misleading............every farmer I know adds "excess", but in research and in any Hydroponics control, we provide a "non limiting" control for an example to compare fertilizing treatments.

    So thinking about it like that, as a non limiting fertilizer method is a better wording, one that is not subjected to some waste based agenda, which matters little to any aquarist. If waste and excess are truly the goal, then a non CO2 approach with much slower growth rates, less electical cost should be used.
    As far as I am aware, EI is the only and has been the only non limiting nutrient method available.. So it invites criticisms more than any method that claims you should limit. I do not critque those methods based on semantical BS, I understand why they work in that context and test. Then discuss the trade offs. I also do not co opt other peoples methods and call them my own. I give credit where it is due.

    I used it like any researcher might when doing fertilizer test growing a plant/crop/ornamental etc. This is not some unknown concept I pulled out of a hat. It really is basic elementary test methods used in agriculture, horticulture, livestock, Plant Ecology, Plant Molecular Biology etc etc..........

    This way you can see/measure differences due to some other factors other than nutrients........ very easy way to rue things out, then you can focus on CO2 and light(which it most often my focus, not nutrients, they are easy to address and rule out). CO2 is the trickest nutient, but it's not an issue in agriculture testing.........only with aquatic plants since they are limited due to diffusion rates.

    So I look at non levels as the lower min ranges for this and the upper bounds, where salt stress occurs from all the fertilizer salts. This is how you do risk assessment for fertilizers at the upper ranges. Now you know the range of
    fertilizers that provide non limiting conditions. So now we can compare things like light and CO2 with the same reference point(which is why a control is used). There's plenty of variation between test, aquariums etc, but using a control addresses that variation.

    2nd,
    Concentration drives uptake rates which drives growth.
    Would you not argue this same idea with CO2?
    Is it not the same arguement to suggest that we keep 3ppm of CO2 with high light aquariums to avoid waste and excess CO2, the number one killers of fish and shrimp in planted tanks? Why add 10ppm? 20ppm? 30ppm? How much can we add? What about O2?

    To date, not one person other than myself has shown that any KNO3 dosing is toxic to fish and shrimp and in my case, only shrimp at 160ppm+. Pretty high. Not one.

    Aquarists are more concerned about fear of killing their critters than answering such questions. Some aquarists make mistakes and then are often amazed that their critters made it through. Then they have doubts about such wishful claims about high NO3's ill effects. I've found this with Shrimps lately, everyone's making lots of claims and no one is really doing much test to see if what they say can be confirmed.

    Back to your question.
    While adding say 1-4ppm of NO3 per day for the uptake of a planted tank works, it does depend on how much is there to start with. For maximal growth, Geoff(1966) found that the growth no longer improved with the addition of about 30ppm of NO3, the 90% range was 20ppm to about 80+ppm.

    A huge target.
    Growth dramatically dropped the lower the NO3 got from 20ppm.
    Here's a graphical example of nutrient concentration on the bottom X axis(increases L to R), and the yield, or growt rate on the Y axis.

    [​IMG]

    But the rates of growth relative to the ambient starting point, say 20ppm NO3, are also subjected to adaptation. Plants use more efficent enzymes to take up CO2, NO3, PO4 etc when they are high levels in the environment. So the plants adapts and makes a host of uptake transporting enzymes that match it's environment.

    This way the plant can be best suited to maximize growth, flowering, seed production, tuber formation, competition etc.

    The same is true for Rubsico and CO2.
    This is why plants can live in many different conditions.
    What is key here is that they are stable and that you reduce light to control rates of growth. In nature, we cannot control light, so we really are only left with maintaining stable conditions and limiting/adding nutrients. In aquariums, we can control every parameter influencing growth pretty easily.

    All these enzymes require a lot of nitrogen to make the proteins. Plants can and do use enzymes like sources of N, when conditions change, they chop them up and make new more effienct enzymes able to take up smaller amount from the external environment, but it takes time and more energy to do so.

    Plant has no choice but to try and adapt, they cannot run away like a critter.
    But if there's no N or is always very limited, then the rates of growth are reduced.
    Same for any nutrient, light or CO2.

    Light is where it all starts, then CO2, then lastly, the nutrients.

    I think this should answer the basics about why a plant will do okay in a wide range of nutrients. It also explains why EI produces such demand on CO2 and why the rates of growth are very fast.

    Now, while I've stated that you do not need test, you most certainly may test and test well, in conjuction. There's no rule I've said that you cannot do that, only that based on the model, there's little need. I did until I convinced myself that there was need and looked into the maximal build up possible. Many folks go this route. No need to see based on faith alone, test and convince yourself.
    "Infinite series" in math speak. See the PMDD thread on The Krib (Aquaria and Tropical Fish) for more at the end, they discuss the same idea with Fe.

    Regards,
    Tom Barr
     
  5. VaughnH

    VaughnH Lifetime Charter Member
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    Testing weekly wouldn't work in any case. If I dose just what the plants will consume in 24 hours, and do that dosing every day at the same time during the day, when do I test? If I am correct in that I am dosing just what the plants will consume that day, there will be zero nutrients in the water at the time I dose. But, I will have no idea when the amount went to zero. So, I have to overdose so I will have a non-zero amount to measure when I do the testing. This seems to be getting complicated.

    PPS Pro tries to dose just what the typical tank needs every day. But, what is a typical tank? Our tanks range from having growth rates comparable to Formula One racing to tanks more like turtle races, from tanks without a single square inch of substrate visible, to tanks with a big clear area in the middle, etc. All of those tanks have different needs, as far as total nutrients consumed per day is concerned. Now, we are getting complicated again.

    I like simple things, and EI is simple. I like effective methods, and EI is effective.
     
  6. Tom Barr

    Tom Barr Founder
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    I'll take this farther here and look at enzymesa bit.

    [​IMG]

    This is another good gragh showing the zones. EI targets the D zones. Limiting methods bob often(unless you are careful) between B and C zones.

    In the "A" zone you get severe stunting.

    This is how and why some limiting methods do well and reduce the rates of growth by limiting a nutrient. But.............

    Now apply CO2 to this same graph.
    How might is change things and growth?
    How might it change the demand for say NO3?
    High CO2(in the D range) vs low CO2(say in the C or B, or A range)?

    Why doesn't PPS argue in favor of no CO2 enrichment if it's all about reduction of waste/water changes/reduced growth and easier? Why use ADA aqua soil? A large reservior of N?
    Why not argue in favor of less light?
    Why not go non CO2?

    Light can be applied to this same graph also, then the demand for CO2 is adjustable, and the demands for nutrients are also adjustable.

    Here's an example:
    So if I want say 5ppm for NO3, and do not want to dose every 2 hours to keep it there, I can reduce the light down to say 40micro mols, then add good CO2,add a sediment based source of N as well, say ADA AS.
    Sediment sources....this will not be measured in the water column, but must be accounted for if you are looking at fertilizers and comparing them.

    I guess where the nutrients are are ignored by many. Tunnel vision with testing NO3, but no such care when it comes to CO2, light, or sediments.
    This leaves out huge unknown factors that need addressed if you are going to compare things.

    It's not some mystery, it's not "there's so much we do not yet know" BS either. It's known alright...........

    Plants will go after both locations however, but we cannot easily test the sediments. ADA tanks are not that lean if you measure the sediment and water column and the fish waste, relative to the low light used. I have the smaples being tested from both ADA AS and PS. They will be published once they get them back to me.

    I use ADA AS + EI. Aquatics are better adapted to take up nutrients from the water column than terrestrial plants, but this will give you an idea of the synergistic effects:

    [​IMG]

    The N ferilizer is foliarly applied in the above figure.
    Still, with water column dosing alone, most plants will do pretty good and hit the D range in the 1st graph. Adding sediments will provide a long term back up, while water column dosing will provide less draw from the sediment, extending it's life and maxmizing errors and reducing deficiency risk.

    If you add low light to this, now you have a very robust method that will handle both low and rich nutrient levels and be easy to manage as far growth rates(slow, but still fast enough) and easy CO2 non limiting levels that are stable.

    Low light also means less algae.

    How can PPS or any method argue so strongly in favor nutrient limiting or adding "just enough", without also arguing in favor of lower reduced lighting?
    Adding "just enough light"? I've long told folks not to add high light, I've provide example after example for over a decade to this effect.

    Seems some folks want their cake and eat too:rolleyes:
    Do you see the fallacy in such logic? How the comparing between the systems is flawed if you have no control, no reference?

    If you decide to take philosophy and want to suggest it's the best method, then you really need to start at the beginning, not the end, otherwise the tail wags the dog. Surly folks can see that light starts things, then CO2 on down the line, so get to the root of the issue, not something 3-10 steps away.

    This is very basic logic and agriculture, not something "new", or something I came up with all on my own out of a hat. I give folks the credit, and do so generously.
    EI comes mostly from PMDD, just made it simpler and used the methods already being used, te only thing I added was more and PO4 dosing.

    Hopefully if lower nutrients or higher are the goal, or explaining how both non CO2 and CO2 systems work..... are now a bit more clear about the best way to go about it.

    You need to consider all the factors that influence growth(starting with light and CO2), not tunnel vision, when deciding on which method has the trade offs you desire.

    This will help you (and advice you give to others) in the future.

    Regards,
    Tom Barr
     
  7. Tom Barr

    Tom Barr Founder
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    You mean this method I suggested in 1996?

    http://www.barrreport.com/estimative-index/2386-old-version-1996-1997-list-levels-parameters.html

    Yes, you can dose it down and reduce EI if you want.
    Then have your own custom EI or what we once called "West Coast lean dosing"(Erik).

    What I and others realized was that we did not need the test kits really. It was not just myself, it was most the folks on the APD and in the local club. So EI came about rather fast, most folks had been testing and the groups knew a lot more about that back then, few alternatives really.

    We also had much less light in general back then.
    PC lighting was just starting to be reasonable in price(A&H supply etc).

    So knowing what you know about light..........now you have more wiggle room to run things leaner.

    This is but one method, but it was the 1st to suggest PO4 dosing and that it was not a limiting factor with algae. No other methods I know of look at algae and limitations, nor consider it in the dosing routine effectively.

    They still are stuck in the adding more nutrients will = algae, this is BS.

    PPS, ADA, every known method out there has copius examples of algae issues, so it cannot possibly be due to limiting nutrients...........can it?

    EI has plenty of examples of algae but importantly.........plenty of examples where there is no algae and high PO4, NO3, Fe etc.............so it has to be something other than nutrients in and of themselves.

    No way around that logic.

    Still, suggesting no test kits and that non limiting nutrients do not cause algae, caused a lot of ruffled feathers and poo pooing my way and with EI.
    Both are radical departures from what has been done in the past.
    But I am not that concerned with nutrients, I find much more interest in light and CO2.

    I think more aquarists should focus on those.


    Regards,
    Tom Barr
     
  8. Tom Barr

    Tom Barr Founder
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    Actually, you can test weekly once every 2-3-4weeks etc.
    You will not have response time and adjust on the fly, but you can simply freeze samll 20 mls samples in a bottle and place in the refrigerator.

    Then say after a week, 2,3-4, week's worth are collected daily(or 2-3x a day, whatever frequency you are interested in) from each aquarium, you can sit down and thaw them out and test for NO3/PO4 etc.

    This way you test all at once and use the same calibrated test kit and method, timing, lighting for color determination etc, you reduce errors and can see long term patterns with far less work and effort.

    The trade off is you cannot adjust the dosing while you test daily etc.

    Regards,
    Tom Barr
     
  9. Tom Barr

    Tom Barr Founder
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    So how is that different from say PMDD?
    The same targets, the same nutrients, etc............is this really "new", or is this method really just PMDD + PO4 (which I and Steve should be credited for, along with those involved with PMDD)? I have lttle issue when folks write their version of a method, but at least give credit. Ed never did that. I do all over the place.

    Regards,
    Tom Barr
     
  10. JDowns

    JDowns Lifetime Charter Member
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    I see this as problematic also. With the partial CO2 data from the in-situ meter, and the wide ranges of results. Wouldn't it be logical given "circulation issues" that different readings for nutrients could also vary depending on the location of the test sample?

    [/end quote response]

    Also. Our tanks are anything but static. From growth rates accellerating due to upward growth, resulting in higher light levels at the crown of the stem plants. Increases in mass, decreases in mass due to trimming. There are many variables that would cause fluctuations in uptake. Aren't you running a higher risk of drifting into zones B & C?

    Hobbyiest test kits as mentioned are far from reliable. Even given testing against a known solution. The color charts have such a wide range of points. The only way I can see being somewhat confident in accuracy would be to make "known calibrated solutions" at small intervals and comparing to your test sample every time you test. Otherwise I don't see it any other way then a pure ranged guess. At that point I would think your plants would give you a better indication of nutrients based on deficiencies. But why would you hover at those zones of deficiency?

    Given the challenges for hobbyiest, especially new hobbyiest, with light, CO2, and circulation. Why would we add more challenges to the hobby.
     
  11. VaughnH

    VaughnH Lifetime Charter Member
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    I realize that PPS Pro is nothing new, but it has built up a lot of adherents because it is a method where you can always get an answer just by asking Edward, and the answer usually includes some reference to "no one really understands just why this happens, but". Like some algae just grow because it is September 22nd, and that algae does that every year at that time. My impression is that it makes a lot of people comfortable to think that this is a mysterious process, and their confusion is shared by everyone, but if they just ignore what they see everything will soon be ok again.

    (I acknowledge that I have a lot of prejudice against PPS Pro for many reasons, mostly not associated with fertilizing...)
     
  12. laka

    laka Prolific Poster

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    Wow!

    I did not know nitrate levels
     
  13. Gerryd

    Gerryd Plant Guru Team
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    laka,

    I have a 180 and I just doubled the 100 gal EI dosing as a start.

    You take the total amount you dose per week and divide by the # of times per week you will dose. If you dose all at once, you will be limited by the end of the week.

    You are both low and high light the way you are going but this is just a guesstimate as wpg is not that scientific.

    Higher light will drive higher growth rates and higher demand for ALL nutrients including c02. Just because your DC is yellow does not mean you have sufficient c02.

    I am now at the following daily dosage:

    1.5 tsp of Kn03
    1 tsp of ks204
    15-20 ml of tropica plant nutrition..

    EI can be different for each tank. You have to adjust and check to get the right amounts for your tank. Don't forget as the plant mass increases, you need to increase your dosages.

    Hope this helps.
     
  14. Tom Barr

    Tom Barr Founder
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  15. JDowns

    JDowns Lifetime Charter Member
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    I dose about the same as Gerry for a 150g.

    Current Daily Dosage.

    1.0 tsp KNO3
    0.5 tsp KH2PO4
    0.5 tsp Trace

    I would consider the lighting on the medium to high side.

    I run 240w for 8 hours. Growth rates are faster than I wish with weekly trimmings of Rotala's and Ludwigia sp's. I can't really run less wattage due to spread issues so I'm playing around with a screening to cut down on the intensity.
     
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