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The Estimative Index Fertilization Method

Discussion in 'AquaScaping World Magazine Discussions' started by John N., Apr 10, 2008.

  1. John N.

    John N. Administrator Staff Member

    Oct 30, 2007
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    Please discuss and comment on Tom Messenger's The Estimative Index Fertilization Method here.


    -John N.
    Jack likes this.
  2. Pat7676

    Pat7676 New Member

    Feb 25, 2008
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    Jackson, Mississippi
    This is a good article on EI method explains it very well. Can you do this without using traces? Also what are good traces?
  3. Left C

    Left C New Member

    Feb 27, 2008
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    Burlington, NC
    Hi John

    You say the following in this article about EI and it's not really accurate: "Sometimes, but not necessarily, people will add Magnesium Sulphate (MgSO4) to help with the buffering capacity of the water (measured as KH)."

    MgSO4 or more commonly used MgSO4∙7H2O increases GH and not KH. Carbonates and Bicarbonates increase KH.

    Take care,
    Left C
  4. plantbrain

    plantbrain Aspiring Aquascaper

    Feb 25, 2008
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    California, USA
    I'll ask a simple question: how does a plant grow?

    Nutrients alone?

    Clearly not.
    Light comes to mind as the first requirement.

    CO2 is next but only suggest 30ppm.
    This too is not correct.
    While at HIGH light, 30ppm CO2 will saturate some plant species, at lower light, say 80 micro moles, the demand might only be at 15 ppm or less.

    The problem with most discussions about nutrients are where the nutrients are located(sediment, fish waste, water column) and the other factors, such as CO2 gas addition and how much light you have.

    Common sense goes right out the door.

    EI works best for high light and very dense planting is not true. EI can and does work fine at low light, at less than dense plantings. You obviously do not need to add so much for tanks, it's likely wasteful, you know the plants are not using that much nutrients but you still dose the same amount simply because "so and so" said so?


    If you have a nutrient rich sediment, say ADA aqua soil, do you still need full EI? No, you can reduce the macros by say 1/2 and still maintain the traces. Sediments supply another source, so the full demand on the water column will be less.

    I suggest for a low light tank, say 80 micro mol, 10-12 hour day, about 1/3 EI, and about weekly water change every 2-3 weeks.

    Likewise, some folks like water changes 2x a week say 20% vs 50% once a week, you can do 80% every two weeks etc, you just need to figure how much possible build up is there.

    You can tweak the dosing using some good test kits also if you chose.
    But folks have lots of trouble using test kits correctly and are often too cheap(Rarely buy the Lamotte or high quality equipment) and forgetful to use them well over time.

    With good reason too.

    "Not using test kits" is a huge a selling point for the method if you can do weekly 50% water changes, and never build up beyond the 2x max weekly dosage.

    Some add EI without any modification, some think you must do 50% water changes weekly, some add it on non CO2 tanks, some have hardly any light and think they are not adding enough KNO3 when doing full EI.

    Folks have trouble measuring CO2 well.
    Folks do not even measure light.

    It's just a concept to dose non limiting nutrients and do water changes to reduce the build up.

    Not much more than that.
    You start at a high known non limiting amount, then reduce it down from there slowly and progressively till you hit a sour effect with the plants, and then bump it back up to the next highest level.

    The actual amounts suggested do not cause algae at high light levels(and therefore cannot induce algae at any other lesser values as well) in and of themselves, this is true no matter how bad folks want to claim otherwise(and many still cannot get this out of their heads).

    So that leaves CO2 and light as the main controlling issues for growth.

    Using GH booster is my general suggestion for Ca,Mg, and K+ added extras.
    They do no harm when adding a bit extra to supplement just in case you are low, basically going back to the idea of non limiting nutrients.

    You can easily provide non limiting amounts of nutrients, then focus on what really matters, good CO2 dosing/light without interference from the nutrients.

    Light and CO2 are much more difficult to address.
    But should never be left from the discussion.

    We should look at the whole process of plant growth and development, not just the nutrients. No method will work without giving due consideration to CO2 and light. I'd say that light and CO2 trend to be far more important over all, but most aquarist fiddle a lot more with nutrients.

    Folks do not read it even if you write though:)
    Thanks for the write up:=D>

    Tom Barr
  5. aquaticscapes

    aquaticscapes New Member

    Apr 18, 2008
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    Faribault Minnesota
    Thank you!

    Hello Tom, we have numerous discussions over the years, some things we agreed with and some not (ex. heating cables). Thank you for addressing the variables in the EI, some of my customers (our online aquarium plant store) who used EI had problems with it not understanding the issues you addressed here. I have always been a less is more kind of guy, I use the chart in the back of the Optimum Aquarium book for CO2 levels based on the carbonate hardness, and use fish loads and their feeding frequency and amounts in my personal tanks to maintain phosphates and nitrates (I never test once I establish levels according to fish load feeding schedules and amounts). I have been successful in avoiding algae and obtaining good vibrant plant growth this way. I have always changed 25 percent water per week. I also use small daily doses of ferts (micros, iron, potassium) in addition to weekly doses. I have never had to tear any of my personal aquariums down due to problems, some have been up and running over seven years. Again, thank you for the addendum to the EI method! Don Matakis
  6. Brilliant

    Brilliant New Member

    Jul 19, 2008
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    Depends on the requirements of plants. I use Tropica Master Grow - now called Tropica Plant Nutrition trace fertlizer. Its getting too expensive so I buy it by the 5liter when on sale or free shipping offer comes.

    Like now...Tropica Plant Nutrition Liquid 5 Liter at Big Al's Online

    Some great points made here. I would also like to add that I dose several weeks of this EI mix (and Tropica trace(on seperate pump)) in liquid form via autodoser. Works great that way too.
  7. Shadow

    Shadow Moderator Staff Member

    Aug 8, 2008
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    In the article it mention "You should look at around 20-30ppm of NO3", is this daily concentration or weekly concentration? Do I need to dose KNO3 20-30ppm everyday?
  8. PMD

    PMD New Member

    Sep 17, 2008
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    Chicago Suburbs
    20-30 ppm of KNO3 is what should be maintained in the tank during the week, not added to it every day.

    If you follow the EI recommendations for dosage of KNO3 during the week, then the proper level of KNO3 will be maintained for the entire week.

    The 50% weekly water change just ensures that the added nutrients will never more than double in the tank.


  9. plantbrain

    plantbrain Aspiring Aquascaper

    Feb 25, 2008
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    California, USA
    Been awhile, catching up:)
    If you subscribe to less is more/better philosophy, then you ought to go whole hog and not just pick and chose where it suits.

    I have no qualms whatever someone's goal might be.
    However, if there is a conflict in the trade offs and general logic, that will raise the red flag quick. I think if you want less, it should certainly start with less light, since this is the driving input of energy.

    This cost the most $ also, water is 100X cheaper relative to increasing water changes vs light 2x.

    Less light= less CO2 demand, which means easier respiration for fish and more stable carbon supply for plants. And less algae since they are not limited by nutrients or CO2, only light is the parameter that limits them directly.

    Now we get to nutrients.
    It's a ways down the line up there, and that's why we can go all over the place with nutrients, have them all work in different tanks, but importantly, not in others. There's more to it than nutrients.

    With less light= less CO2 demand= less nutrient demand.
    Like a non CO2 water column dosing method, you can scale EI up/down to suit the targets of ppm's for each you set for yourself.

    In low light tanks with ADA AS, adding 1/4 of EI works fine, there's less light and a back up in the sediment.

    25 years ago when Dupla came to the USA, folks used about 3-4x less light than many folks seem to have these days, that clearly makes a hige difference. Sediment rich soils, clays also make a huge difference.
    All these issues are integrated, one isolated does not tell the whole story.

    If there's a general goal that believes less is better for their aquarium, then start with light, then look at adding just enough CO2, and finally, look at nutrients and both locations. Nutrient dosing is dag easy, so is measuring light if you have a decent light meter. That leaves CO2, and some general plant growth concepts about how light drives uptake.

    Very easy and a wide wide range, less labor etc for nutrient management. You can slowly adjust ther EI dosign down also till you hit a negative response, and then bump the dosing back up to the next highest level. Probably get away with less % or less frequent water changes, say 25% weekly or once every 2-3 weeks etc.

    I can anyway without much trouble.

    Tom Barr
  10. lalmeida

    lalmeida New Member

    Sep 12, 2010
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    Azores, Portugal
    tsp measure

    I was reading about EI and bumped on this.
    Can anyone clarify me about the tsp measures? What is the equivalence in millimeters for 1 tsp?
    I’ve used an on-line converter (http://www.onlineconversion.com/cooking_volume.htm) but I cannot achieve any the results I’ve found on this article (http://www.aquaticplantcentral.com/forumapc/fertilizing/15225-estimative-index-dosing-guide.html) where:
    1/8 tsp = 10 ml
    ¼ tsp = 20 ml
    ½ tsp = 30 ml (this must be 40 ml, correct?)
    Anyway on the converter ¼ Teaspoon [metric] = 1.25 milliliter!
    Sorry maybe I’m completely confused but there is something I’m missing :frusty:

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