EI Dosing Calculation Confusion

Discussion in 'Aquarium Fert Dosing' started by firstman, 15 Sep 2009.

  1. firstman

    firstman Member

    Messages:
    32
    Location:
    United States
    Hi all,
    Wanted to run some things by you as I am a bit confused. I just ordered my dry salts and am going to give EI a go. :D Looking on James' page it states you should dose to achieve the following: Nitrate 20–30ppm, Phosphate 1-3ppm, Potassium 20-30ppm.

    But then on the Dosing Calculator page it states: 8ppm of Nitrate(KNO3) which is added 3x a week and
    2ppm of Phosphate(KH2PO4) which is added 3x a week.

    Ok, so here's my confusion. If you take 8ppm KNO3 (x3) times a week reaching a total of 24ppm for the week, this would be within the 20-30ppm stated. But then the 2ppm dosing of KH2PO4 (x3) times a week would put you at 6ppm which is double the highest level stated. What am I missing? Am I doing something wrong? :?

    And as far as Potassium is concerned, if I use the calculator to find the proper amounts of salts to add to get 8ppm KNO3, and 2ppm KH2PO4. I get 5.06ppm Potassium from KNO3 and .82ppm Potassium from KH2PO4. Multiply by 3 times a week and you get 17.64ppm. Just a bit lower that the 20-30ppm.

    Maybe you could shed some light on this for me. Not sure if I am misunderstanding the calculations or am missing the whole concept of 'Estimative' Index.

    If you want to use the calculator to check my findings. I have a 39 US gallon tank and will be dosing dry. So I am looking for gram weights.

    What I came up with is this: .42 grams KH2PO4 = 1.99ppm Phosphate and .82ppm Potassium (if 2ppm is correct level)
    1.93 grams KNO3 = 8.01ppm Nitrate and 5.06 ppm Potassium

    I just want to know what parameters I am shooting for so that I can do this properly (with all the help I can get). ;)

    My plants and fish thank you.
     
  2. BINKSY1973

    BINKSY1973 Member

    Messages:
    201
    Location:
    Oxford
    Hi,
    First off have you read the article here on UKAPS about EI dosing?


    Here's the lik below for you if not. It will more than likely take a couple of reads to get your head around it.

    http://www.ukaps.org/EI.htm

    I would also say you will find it easier to make up a solution in two bottles, one with the trace, and the other with KNO3, KH2PO4, MgSO4.

    So the amounts you would need are as follows.

    2g KNO3 3X
    0.67g KH2PO4 3X
    6g MgSO4 3X
    0.67g traces 2X

    KNO3 => 2g X 12 = 24g to 200ml or 60g to 500ml
    KH2PO4 => 0..70g X 12 = 8.4g to 200ml or 21g to 500ml
    MgSO4 => 6g X 12 = 72g to 200ml or 180g to 500ml

    Trace => 0.70g X 8 = 5.6g to 200ml or 14g to 500ml

    With this dosing regime you have two rest days before water change day, i would also advise to mix up the 500ml solution as you will dose 40ml, as opposed to 16.6 ml

    I hope my figures are correct, and i know the above may be confusing to start with, but once you understand it, it is very easy.

    Cheers Gordon.
     
  3. firstman

    firstman Member

    Messages:
    32
    Location:
    United States
    Thank you for your response. Yes I have read the article. It is very informative. :thumbup:
    It would seem that this would raise the level of KH2PO4 even more than the .42g I had mentioned. This would take the total level of Phosphate to well over double the highest level suggested on James' page. This solution confuses me even more. :?
     
  4. firstman

    firstman Member

    Messages:
    32
    Location:
    United States
    Wanted to let you guys know that I got a PM response from JamesC about my questions. And here it is.
    So there you have it. As was one of my thoughts, it isn't an exact science, but an 'Estimative Index'. :lol: :text-imnewhere:
     
  5. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    And just to add that myself and others actually find that having higher levels of PO4 when dosing EI is beneficial compared to the suggested level figures in the EI article. The EI article is getting a bit old now and may need an update. It's beneficial in that it helps with prevention of green spot algae and some plants like blyxa japonica may flower for you.

    James
     
  6. keymaker

    keymaker Member

    Messages:
    255
    Location:
    Budapest, Hungary
    I have to confirm. For some reason I have extensive feedback from users of an all-in-one solution that we sell that GSA is well present with around 3ppm PO4 in the tank.

    I wonder what Mr. Plantbrain's opinion is on this. I do not think that EI in it's current form is "outdated" though :). But I would want a scientific reason in expanding EI levels - in addition to my (and my contacts') experience.
     
  7. JamesC

    JamesC Member

    Messages:
    1,276
    Location:
    Bexley, Kent
    Green spot is an awkward one. Under EI I've found that you actually need fairly high levels of PO4 to completely combat GSA. There could be reasons for this but I'd only be guessing in saying that it could be something to do with a ratio with NO3. When I've dosed rich EI with high NO3 levels then I've noticed that PO4 levels have also needed to be high to combat GSA. But when I've dosed half EI levels then PO4 levels are a lot lower and no GSA. So it would seem that having a particular ppm of PO4 isn't always the answer and other tank parameters play a part as well. Keeping rich PO4 with different levels of EI dosing doesn't cause problems and is an easy answer if you just wish to stop GSA.

    And here is the big BUT. If dosing a lean dosing method like PPS or what I do with my PMDD mix, keeping the same NO3 and PO4 ratio's as EI causes massive GSA and the answer doesn't seem to be to add more PO4, but less PO4. I've done this several times now on different tanks now and get the same result, though this isn't conclusive by any means. Levels of nutrients in tap water can have an effect as well. Tropica's TPN+ works along similar lines as it also limits PO4 and seems to work very effectively. The hard part is getting the balance right so as not to dose too little PO4 so plants can't grow but just enough to provide their needs.

    I've waffled a bit but hopefully have provided some food for thought.
    James
     
  8. plantbrain

    plantbrain Expert

    Messages:
    1,949
    GSA is a two edge sword.

    It's CO2 AND PO4............not just high PO4 in and of itself.
    EI is not written in stone either, it's meant to be modified to suit.

    It's just a target based on plant demand/growth as a non limiting factor, not algae.
    It has NOTHING to do with algae.

    That is a separate matter altogether.

    I can induce GSA with lower CO2.
    I can also induce GSA by limiting PO4, which was very common and acceptable to many using PMDD back in the day.
    Or a a few other methods that are used today which end up limiting PO4, thereby switching from a CO2 limited system, to a PO4 limited system.

    Many feel that those methods are "better", this is due to improved CO2 management which was not independent to begin with in their tanks. If you want to look at GSA, you need to ensure CO2 is truly independent before looking at nutrients.

    If you strongly limit PO4, then CO2 drops, by 2-3x depending on the intensity and cycling of PO4 limitation.
    You basically are trading one problem for another.

    I hate GSA, some hate BBA more.

    I have little issue with either.

    If you want to use 5ppm of PO4, go for it, I add that much 2-3x a week.
    But it does not correct a CO2 issue.

    Also, realize CO2 is also dependent on O2 with respect to adding more, fish, filtration etc.
    So make sure to focus there.

    It's not nearly as simple as one factor, however, you can focus on the other factors and isolate the factor of interest better by using non limiting levels or higher etc.

    I've been steadily suggesting more PO4 over the years(see PMDD, then recommended parameters/levels, then EI, then some revision of EI).

    I've never liked the idea of a set ppm for any dosing, it's a bit unrealitistic.
    A range seems to always work better.

    Regards,
    Tom Barr
     
  9. keymaker

    keymaker Member

    Messages:
    255
    Location:
    Budapest, Hungary
    At least two important lessons here! Thanks for that.

    I have a very important question to the second issue:

    With all other conditions ideal - non-limiting nutrients and CO2, proper Ammonia breakdown (filtration), regular water changes, etc. - can low O2 level by itself induce algae? Diatoms and/or GSA?
     
  10. firstman

    firstman Member

    Messages:
    32
    Location:
    United States
    So what exactly is considered higher levels? Article says to shoot for 2ppm.What range are we talking about? 3,4,5ppm?
    Don't have an issue with GSA currently (knock on wood). Would raising my PO4 increase plant growth?

    .

    So obviously 3ppm isn't the way to go. Interesting.
     
  11. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Hi,
    I think you're confusing the issues. As explained earlier GSA is both PO4 and CO2 related. So you can have adequate levels of PO4 and still get GSA if CO2 is sub-par. Or you can get GSA if your CO2 is OK and your PO4 is sub-par. Or you can get GSA if both CO2 and PO4 are sub-par. Therefore, people who report getting GSA with a certain level of PO4 may not be paying attention to their CO2. They may also not be paying attention to flow.

    The EI article specifically calls out the causal factors of algae which are not related to the dosing levels. If your flow is poor then it may appear that you need more of everything to maintain optimum health. The higher ppm level therefore compensates for the poor distribution. But this does not mean necessarily that 3ppm is better than 2ppm, only that in that particular tank, under those particular environmental conditions, 3ppm works better than 2ppm. It seems to me that everyone is jumping at the chance to become a numbers anoraks. All of a sudden Number X becomes law just because it happened to work for some person under a particular set of conditions. The EI baseline dosing numbers were never meant to be some sort of Holy Trinity. They were derived from a set of experiments designed to explore the limits growth rates under extreme conditions. They also coincidentally demonstrate that there is no correlation between high nutrient levels and algal blooms. The thing that everyone forgets is that the guy who derived those numbers is an expert at growing plants, so the tanks in which he performed the experiments in were otherwise optimized for flow, distribution, CO2 and so forth. Everyone ignores this aspect of the data and it turns out that this is just as important as the numbers. So there's no point confusing ourselves and each other with this value or that ratio or whatever. Plants are adaptable and their growth performance can be optimized around a range of numbers. Start with the baseline numbers and make your adjustments based on your objectives and your observations.

    Higher PO4 levels result in higher growth rates, so add as much as you want depending on how much growth you want. High growth means high maintenance. 3ppm PO4 can be fine depending on how much light and flow is in the tank. I use 10ppm PO4 just to explore the envelope of shape and form - and I get amazing results not seen in anyone else's tank. But does this mean that I should unilaterally recommend 10ppm PO4? Hardly, because it would be completely out of context.

    Instead of focusing on numbers, use your eyeballs to look at your tank. Change the baseline numbers depending on your objectives and observation, not just because some other number appears on somebody's spreadsheet. If you want higher growth rates then add more of everything - but you'd better have a solid maintenance program because you'll produce a lot of organic waste - and that will kill you if it's not addressed. If you want less maintenance then use less of everything, including less light.

    Cheers,
     
  12. firstman

    firstman Member

    Messages:
    32
    Location:
    United States
    Thank you for the reply Clive. After posting yesterday I decided to look a bit deeper into this whole El dosing thing. After reading the original Tom Barr analysis page , I came to the conclusion that what I needed to do was start keeping track of my parameters, CO2, lighting, dosing, etc. Do this for about a month without making any changes and note the results. Then make your changes, use them for a month, and note results. So forth and so-on. Well, a month is the time-line I am going to use anyway.

    I think that you hit the nail on the head with people looking for a magic number. This includes me. Wanting the ideal ppm to add so that you are positive you are doing this correctly. I believe that we have been pre-programmed by the BIG product companies to think this way. With all the adding of exact amounts of this and that. Using numerous test kits to make sure you don't exceed this, or don't have that. It is all very confusing.

    Then something like this comes along. A baseline set of parameters which will get you going and won't do you wrong. Watch the progress for awhile and see what you want to do next, if anything. Experimentation! :woot: It is hard to de-program yourself from the numbers game that we have all been playing for so long. At least it is for me. The more reading that I do. The more questions I post. The more I understand that there isn't a set number to obtain that is right for everybody, the more comfortable I am with the whole thing.
     
  13. CeeJay

    CeeJay Member

    Messages:
    945
    Location:
    Surrey UK
    Hi firstman
    I do believe we call it the Matrix round here :lol:

    Chris
     

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