100+ppm calcium and nutrient uptake

Discussion in 'Water Chemistry' started by Sammy Islam, 19 Nov 2019.

  1. Sammy Islam

    Sammy Islam Member

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    Thank you for that info i may go back to alternate days if i see any negatives but so far ive seen a positive impact within a week and half. I dose enough k through kno3, kh2po4 and k2so4 in my solution, roughly 28ppm a week.

    So you're saying my iron and phosphate could be reacting causing less potassium uptake than needed?
     
  2. dw1305

    dw1305 Expert

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    Hi all,
    Virtually all potassium (K) containing compounds <"are soluble">, so it won't be lack of potassium, unless you haven't added enough, which I think you've just discounted.
    Yes, that is a distinct possibility, for the reasons that @ian_m quotes.
    cheers Darrel
     
  3. Sammy Islam

    Sammy Islam Member

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    Ok ill go back to alternate day dosing then seeing as ive only been dosing daily for 2 weeks and these symptoms have been on going for months.
    Mainly the hygro curling/wavy edge, and ludwigia leaves are distorted and drooping downwards which seems to be a calcium defiency and theres no way i can have a calcium defiency, right?

    I feel like when i add 2tsp mgso4 to my tank during water change to give me 8ppm thats what contributes to the curling, or i see the curling happen more after water change. But ive tried 1tsp and 1.5tsp which gives me 4 or 6ppm, and it seems that 6+ppm helps my new growth on java ferns from having dark veins.

    I thought if my ph goes above 7(edta) and 7.5(dpta) my iron becomes unavailable? My tank water degasses up to 7.9 when lights are off and with co2 6.7/8, so does that mean my iron wont be available the next day if im dosing alternate days?
     
    Last edited: 2 Dec 2019
  4. MJQMJQ

    MJQMJQ Member

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    Tap water commonly contains nutrients.Curling is due to stress, perhaps changes in TDS when changing water.Perhaps the plants werent too happy to begin with.Distorted leaves is generally too much nutrients or too little.Are u putting root tabs directly below the plants?
     
  5. Sammy Islam

    Sammy Islam Member

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    I have used root tabs in the past but mainly for "root feeders" like my crypts and tiger lotus. I haven't added any in a while because full EI supplies everything that my plants should need. I was thinking maybe the root tabs are providing excess nutrients but i do 80% water change a week to minimize excess ferts etc.

    If my ph goes above 7.5 does that mean my iron isn't available the next day when dosing on alternate days?
     
  6. MJQMJQ

    MJQMJQ Member

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    Full EI is good enough.Iron would be less available if ph is above 7.5 but since ure doing EI no need to worry.Just rmb alternate day dosing cos no matter what the pH is the micronutrients will still react with Phosphorus.Pretty much the same as for soil.
    https://www.nutrientstewardship.com/implementation/soil-ph-and-the-availability-of-plant-nutrients/
     
  7. Sammy Islam

    Sammy Islam Member

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    Ok cool i've set my auto doser to alternate days again and will monitor from there. I might also add the mgso4 twice a week instead of all at water change and see if that makes a difference.

    From further reading i'm assuming not all the iron is lost, only a certain percentage that reacts with the phosphate if my ph goes above 7.5 after lights out? So adding a little more iron will counter that as not all of it will be lost, meaning some/more will be available the next day?

    Do you advise against using root tabs while dosing EI?

    Thanks
     
  8. dw1305

    dw1305 Expert

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    Hi all,
    It isn't only PO4--- that reacts with any Fe+++ ions, in alkaline, oxidising conditions the iron forms <"insoluble oxides and hydroxides"> etc.

    The only way to ensure that iron, in solution, is available to your plants is to use <"a chelator that works at higher pH levels">.

    cheers Darrel
     
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  9. Sammy Islam

    Sammy Islam Member

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    I understand what you are saying. Surely the fact that my plants are pretty healthy and colourful in general would indicate that the iron (edta+dpta) is working to an extent and maybe not to its full potential given the other parameters we have to consider and perfect eg. co2, flow, ph etc
     
  10. dw1305

    dw1305 Expert

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    Hi all,
    Yes, I always say <"trust the plants, they don't lie">.

    Some iron is usually enough, and it is about the only deficiency that you can <"easily diagnose">, because of it effects new leaves.

    cheers Darrel
     
  11. Sammy Islam

    Sammy Islam Member

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    IMG_20191203_142418.jpg So does the iron still react with other things even though we dose alternate days but not as much if we added on the same day?

    What else can cause drooping leaves on plants such as ludwigia? Could it be that ludwigia prefers a little bit lower gh/kh? My other plants don't seem to show this defiency.
     
    Last edited: 3 Dec 2019
  12. MJQMJQ

    MJQMJQ Member

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    Is it recently bought?If it is it might be due to difference in hardness and nutrient levels.
     
  13. Sammy Islam

    Sammy Islam Member

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    Yes that plant is new and adapting to under water life, but i also have some old ludwigia that shows the same symptoms. Mainly twisted leaves and drooping/hook downwards.
     
  14. Oldguy

    Oldguy Member

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    I agree a very big Hmmmm. Chelated iron is often available as either the sodium salt (cheaper) or the potassium salt of the complex. These are aimed at top fruit growers as a folia feed. No leaf curl in these situations.

    As you rightly point out the dilution in tanks is such that cloudiness will not be seen at normal dosing levels. At very high levels cloudiness from precipitating iron hydroxide would be noticeable as would the resulting yellow/orange colouration of iron oxides coating plant leaves and invisibly coating fish gills with accompanying distress. This level can be seen in natural waters issuing from sandstone flushes. For 'tomato soup water' there is a mine outflow a few miles from where I live and it influences the receiving water for its entire length with a grey/white cloudiness still present in its lower reaches.

    Hardwater and chelated compounds. There is a good probability of iron and other transition metals present as chelates being displaced by group two elements and having as a result a short half life in solution for plant availability.

    I think that the chemistry of our tank water is a nightmare unless you have daily access to a first rate analytical lab. School chemistry only works when every reagent is about 0.1 molar. However life would be boring if everything worked, but it would be restful.
     
  15. Sammy Islam

    Sammy Islam Member

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    So even when dosing alternate days the does iron still react with phosphate due to the remaining macros dose from the previous day even if the iron is released slowly from the chelator depending on ph? And if it doesn't react, why?
     
  16. ian_m

    ian_m Global Moderator Staff Member

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    The micro, especially the iron, once in the water tends to get depleted quite quickly due to:
    - Absorption by plants.
    - Unchelating due to high pH. Last longer in a CO2 injected, low pH tank.
    - Chelate breaking down due to light. Most chelates are light sensitive.
    - Bacterial action scoffing it.
    - Reacting with left over phosphate.

    I am sure I read somewhere the chelates only last a couple of hours once in the tank (as short as a couple of hours), due to all the above. I dose my macro/micro at same time CO2 comes on and two hours before lights come on. Not seen any plant nutrient issues.

    Below is the standard graph of % chelation vs pH.
    [​IMG]

    Many people have tried DPTA iron, to survive better in hard water, so they say, but it does tend to make the water pink.
     
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  17. Zeus.

    Zeus. Member

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    Fe DPTA is light sensitive also so breaks down when light is on and it doesnt make the the water as pink as Fe EDDHA but Fe EDDHA is light stable and better for higher pH also.

    I find the pigmentation Fe DPTA does as very acceptable its just its light sensitivity that makes it no so good for our tanks IMO/IME
     
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  18. Oldguy

    Oldguy Member

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    Photo degradation of FeEDTA with Time in Commercially Produced Soluble Fertilizers ie Master Blend and Peters. by: Joseph P. Albano and William B. Miller www.researchgate.net/publication/279648904

    upload_2019-12-4_19-6-42.png
     
    Last edited by a moderator: 5 Dec 2019
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  19. Sammy Islam

    Sammy Islam Member

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    So that graph is saying iron in small amounts lasts quite a long time before it degrades from light?

    What about breaking away from the chelate at higher ph nearer 7? Does break down 100% so no iron would be available at all?

    I've mixed in dpta to my micro mix and it isn't pink at all, more dark orange which doesn't discolour the water that much. I
    assume most people in the uk live with hard water with parameters probably close to mine.

    Do you just dose full EI on alternate days with the edta iron in the trace mix?
    Do you supplement with dtpa aswell?
    Do you dose more than you need to because of hard water?
    Do you add trace/iron more often than EI calls for?
     
  20. Oldguy

    Oldguy Member

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    I dose full EI on alternative days. I dose EDTA iron together with a EDTA trace element mix. These I make up from dry powder and are dissolved together in rain water. I dose for a target Fe of about 0.2ppm on the other alternate days with other trace elements at about 0.02ppm. I do not know the dose according to EI and I dose at the same rate for both high and low tech tanks. Iron is a vital macro element and may be virtually absent from tap water. (Calcareous bore hole water will not contain iron and iron in waters from other sources is often removed in treatment plants so that people don't complain about iron stained laundry.

    My tap water is moderately soft/hard depending how your point of view. I cut it 50:50 with rain water and then add MgSO4 solution twice a week to bring the hardness back up to soft/hard. I have no scientific reason for doing this it just finds some use for the rain but it does stop limescale built up. Magnesium is often overlooked as a vital element for plant growth, with people assuming that it will be in the tap water.

    I grow plants that I can grow. The big balancing act is light levels/duration and CO2 levels in the water.

    Hope that this has been of some help.
     

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