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EDTA Concentration

Discussion in 'Advanced Strategies and Fertilization' started by ismenio, Nov 29, 2009.

  1. ismenio

    ismenio Guest

    Hy

    Tank 360L or 96 Gallons
    Light: 8 hours with 2 x PL 55W 7200k and a plenty of natural light (not direct light)
    Substrate: Only river sand.

    Fertilization: KCL 10 ppm every week after 50 % water change

    NH3/NH4 and NO2: 0mg/L
    NO3: 10mg/L
    PO4: 10mg/L

    The leaves of my Echinodorus Grandiflora is disappearing, some are turning brown others are come apart and i think that is the Fe missing.

    I have bought EDTA and now i have some doubts:

    1- The bottle of EDTA have 1 liter and i says two things, one is 0.01 mol/L and the other is M.=372.24 and i thing this tell me that i have in one liter 3.72 g or by others words 3.72g/L, is this correct?

    2-So if i have 250 liters i should but directly from the bottle of EDTA 30 mL to have
    0.1 ppm of Fe, is this correct?

    3-I should put some compound with Iron ? EDTA only helps the plants to absorber the Fe, is this correct too?

    Has you can see

    [​IMG]

    Regards
     
  2. Gerryd

    Gerryd Plant Guru Team
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    Hi,

    Are you adding c02 at all to this tank?

    If not, a 50% water change will cause flunctuations in c02 levels and produce poor growth. If you are, can you describe how you diffuse and measure it?

    I can't answer your iron questions sorry.

    What is KCL? Please note that any retail product of ferts will be watered down, so you may be adding less than you think. Also, most test kits are not accurate to measure the smaller amounts of chemicals. Unless the kit is calibrated against a KNOWN solution, I would hold the results suspect at best.

    Hope this helps somehow.
     
  3. ismenio

    ismenio Guest

    Thanks for you help.

    I don´t have CO2 and KCL is now as potassium.
    Normaly i don´t do tests to the water since i use EI.

    Regards
     
  4. Gerryd

    Gerryd Plant Guru Team
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    Hi,

    Since you are NOT using c02, it may be better that you do not do water changes as frequently.

    Swords are big plants and require lots of nutes including c02.

    Can you provide a picture of the tank or let us know more about it?

    Substrate used, type of plants and how many, etc?

    Are you ONLY dosing potassium? Need nitrate and phosphate as well as micros.......

    I think your issue is c02 and not iron. It looks like you have some BGA which can be caused by low N.

    How are the other plants doing?
     
  5. Tug

    Tug Lifetime Charter Member
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    Hi all,
    I am interested in the mol/L question as well. It's to bad the package doesn't just give you the mass-volume percentage of Fe in a way that most of us could work with without needing a background in chemistry. Just a side note, but if you have moderately hard water, consider using DTPA Fe.

    Another issues you might need to consider is providing/improving water current. Before I began adding CO2 to the water column, improving the water flow helped my situation a great deal.

    +1 Gerry's comment on water changes. It reduces fluctuating CO2 levels and allows plants time to adapt to the available carbon source.
     
  6. ismenio

    ismenio Guest

    Hi

    Trying to respond to your questions

    I don´t have hard water, is very soft 3gH
    Substrate, i don´t have substrate

    Yes i´m ONLY dosing with potassium, nitrate and phosphate are at 10mg/L
    The the plants i have are a lot of Echinodorus Grandiflora and one big Pontederia Cordata that is ok with almost 2 meters.
     
  7. Philosophos

    Philosophos Lifetime Charter Member
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    The molar mass seemed off to me, so I did some googling. Looks like you've got Na2EDTA.2H2O so you're getting double the sodium and none of the iron. What you want is the 367.05g/mol Fe (III) EDTA which will give you iron. If you're going to all the trouble though, I'd say just get CSM+B and take care of all your micro issues.

    Your macro dosing is also pretty lean. How accurate are those test kits? Have you calibrated them?

    10ppm KCL = 39.0983/74.551g/mol K+

    So...

    10*39.0983/74.551 = 5.2445ppm of K+ dosed /wk

    You may want to try dosing:

    10*74.551/39.0983 = 19.0676ppm KCL for 10ppm K+/wk

    Maybe try dosing it over the course of the week.

    You clearly have a substrate of some sort; it's what your plants are rooted in.
     
  8. ismenio

    ismenio Guest

    Ok, probably i´m messing around.

    Let´s reset all the crap i did.

    Forget the EDTA, i have bought but i don´t have used.

    The test are from API but i don´t no if they are correct, probably the PO4 is really 10mg/L cause my goldfish love to eat, and the NO3 is only 10mg/L and not higher thanks to Pontederia Cordata.

    And the substrate is river sand only.

    No CO2.

    The KCl i´m dissolving 100mg in a bottle of 2 liter and after make the water change of 50 % more or less 150 liters i had 100 ml from the solution in the bottle.

    What i should do? Increase KCL? How much?
    I friend mine give me a Bootle of Elos Plant I, With Fe and Micros, should i use?

    Sorry the testament but my Echinodorus Grandiflora is going away and i don´t now what to do.

    PS: I don´t have BGA
     
  9. Philosophos

    Philosophos Lifetime Charter Member
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    I wouldn't pay very close attention to those test kits unless you calibrate them. I use the same API test kits and I've noticed that the PO4 tests unreasonably high. By the time you're calibrating test kits, you might as well buy all the compounds necessary to dry dose EI.

    I can't find anything on the Elos site about the analysis for their product. Personally, I don't like to put anything in my tank that doesn't give a good guaranteed analysis.

    For a micro, TPN or Searchem Flourish can work if you can't get CSM+B. More expensive, but they definitely work.

    Dose 20ppm of KCL for now. If those little holes don't go away, on the new growth within a couple of weeks, increase to 30ppm. Use this until you've got the rest of your dosing and column worked out.

    If you can get it, KH2PO4, KNO3 and K2SO4 are the compounds you'll need for basic EI dosing, though there's other ways of achieving it using a combination of tropica and seachem products.
     
  10. ismenio

    ismenio Guest

    Sorry my questions:

    Why use K2SO4 when i use KCL ?
    Why add KH2PO4 and KNO3 when i have (i think) a lot off then?

    Probably i have understand wrong the EI :)

    CSM+B i don´t now what it is but i have access to Tropica and Seachem products, in case i use Searchem Flourish (is this one? http://www.seachem.com/Products/product_pages/Flourish.html) what dose should i use for 300 liters?

    Thanks for yours help
     
  11. Philosophos

    Philosophos Lifetime Charter Member
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    KCL works; stick with it if you like. I'm partial to K2SO4 because I use CaCl2 as well, and I really don't like pushing the chloride up if it's not necessary.

    I don't think your PO4 test is reliable; you can make a PO4 calibration solution with KH2PO4 to find out. If it turns out you need more PO4, you'll already have the compound to increase it with.

    It's the same idea for KNO3 to calibrate your NO3 test.

    If you can get a few grams you should be able to make up a reference solution for each. You'll need access to a scale to make these solutions.
     
  12. ismenio

    ismenio Guest

    Well, the best so is improve the NPK no mater what the tests say and add trace elements.
    But when we have low light 110W for 90 gallons and no CO2 which are the values for fertilization?
    I only find for high light here http://www.barrreport.com/showthread.php?t=2819

    regards
     
  13. Philosophos

    Philosophos Lifetime Charter Member
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    At low light I'd dose 1/2 those levels until everything looks stable. Once you have stable, healthy growth you can try reducing further.
     
  14. ismenio

    ismenio Guest

    Ok , thanks
     
  15. ismenio

    ismenio Guest

    So

    For a tank with 66 gallons i will have to use:

    KNO3 1/5 teaspoon
    KH2PO4 1/10 teaspoon

    And for SeaChem Equlibrium 4/5 teaspoon has Tom Barr say on EI without CO2 but i think there is some confusion with Seachem Flourish like in this link http://www.seachem.com/Products/product_pages/Flourish.html i think this is the correct one or not?

    Sorry my questions.
     
  16. Gerryd

    Gerryd Plant Guru Team
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    Hi ismenio,

    Although EI was designed with high light tanks in mind, the amount of ferts in your tank will NOT reach dangerous levels even if you dose 2 or 3x the EI recommended amounts for your size tank.

    I have dosed 2-3x EI in my 180 many times, experimenting....as do many others. EI is meant to be variable and adjustable for each tank's needs. No need to follow precise measurements......

    That is why a min 50% weekly water change is vital to reset the nutrient level.

    I think you can go with the high light EI for your tank with no issues.

    However, going half is a good way to start and you can increase from that point if need be.
     
  17. Philosophos

    Philosophos Lifetime Charter Member
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    Ya, Flourish Comprehensive. Usually just saying "flourish" refers to comprehensive. If it's another type people will usually distinguish that it's Flourish N, P, K, Fe, etc.

    If you half what ever the standard EI dose gives, you'll have non-limiting levels for a low light tank. You can find those dosage rates here:
    http://www.barrreport.com/showthread.php?t=2819

    It looks like what you've given is about right. Dosing isn't an exact science; as Gerry says, you could dose 3x as much. Given that you're on a 1/2 dose, you can probably go 2 weeks between 50% water changes to start. Longer once you get to know how your tanks works a little better.

    -Philosophos
     
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