The Custom Micro Mix Thread

Tom Barr

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Yeah, but this is exactly the problem. They are standard methods, they don't consider special scenarios such as the presence of strong Fe complexes. Those are usually dealt with during the "sample preparation" phase, but not in our case.

I will try to test it in the lab when I have some free time.


They list interferences(special scenarios) with the method in the Standard methods protocol.
If you use a triazine color reagent, then 10% EDTA can impact the results.
High pH etc. But they generally use a reducing agent as part of the protocol.
They want all the Fe converted to the free Fe2+ form. Most every method does this, but the reducing agents can vary.

Since you suggest that your revised method is true/better/superior/more true, why not do this for all test regarding Fe? Should that not be listed in the protocols for the methods?
Why is that not suggested?


Is a standard reference solution of FE being made also? I see a lot of test and talk, but little on the methods.
No mention of a standard reference being used in testing.

If someone brings it up after the question is posed.......it does not instill much confidence.
Still, as long as it is done.......and included, that does not matter.

Make a standard solution of the Fe. Then you can compare your method with that of the sample and change from the method/s.
Many hobbyists noted that the Fe test kits changed color and became more intense over long time frames. But it goes back to the method.
None of them made a standard reference solution to compare that I recall. Getting them to use a standard reference for NO3 and PO4 test was bad enough.

This way you get around the method time issue and make sure your method is correct(and you can set a new time reaction to correlate with your own data).
Say your data suggest a rx time of 4.25 hours to match your known reference sample using X method.

Note, you can add tank water to make known references and use distilled/RO water etc(say for each type of chelator of interest).
I would do both.
You may also freeze tank water samples and then measure all at once later on. Better than testing several times a week etc.
 
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Phishless

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Well I have compared many different posted dosing schedules from here and TPT.
Added to it all the micro mixes possible based on EI Fe content to it.
Also added suggested dosing from various bottled products to view how minimal they are.
Have not yet included my present dosing as it has been altered.
Not sure what to mix up @ this point regarding ratios etc...
Need to sit on this a bit longer and revisit spreadsheet this eve.

I've been dosing my normal mix @ reduced amounts, but daily.
No cloudy water as before. Wanting to make it cloudy one more time for some explanation though.
 

burr740

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Hey Joe, could you please confirm what you wrote about Ni is a typo: it should be .05 ppb not .5 ppb. Right?

.5 ppb

From what I can gather it has a very low potential for toxicity, far lower than Cu for example.
 

fablau

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@burr740 maybe you missed it, but I’d like to know if your current dosing’s ppms are applied to a reduced tank-volume. For example, dosing for a 75gl tank are actually calculated for a 60gl, etc... just to clarify for everyone. Thanks [emoji6]
 

burr740

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My tanks are 50 gal, 75 gal and 120 gal.

Dosed at 40 gal, 60 gal and 100 gal
 
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zervan

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Make a standard solution of the Fe. Then you can compare your method with that of the sample and change from the method/s.
Many hobbyists noted that the Fe test kits changed color and became more intense over long time frames. But it goes back to the method.
None of them made a standard reference solution to compare that I recall. Getting them to use a standard reference for NO3 and PO4 test was bad enough.
Many people are checking their water tests on reference solutions, me too. I've checked my JBL Fe test on Fe-EDDHMA which I was using for years - and it was measuring fine. It was long time ago, so I made it again now...

I've prepared two 1 liter solutions of 0.7 mg/l Fe - EDDHMA (pink color even in this small volume) and DTPA (no color visible) in RO water. Then I was measuring Fe concentration using JBL test (https://www.jbl.de/en/products/detail/2442/jbl-iron-test-fe), expiration 2/2018. This test has reaction time of 5 minutes, according to the manual. But for all the years I use to leave it on sunshine or on the aquarium cover under strong light until the next day.

Here are the results:
  • Fe-EDDHMA:
    • after 5 minutes 0.4 mg/l;
    • after 2 hours 0.6 mg/l;
    • next day 0.6 mg/l.
  • Fe-DTPA:
    • after 5 minutes almost nothing (less than 0.05 mg/l);
    • after 1 hour 0.6 mg/l;
    • after 4 hours something between 0.6 and 0.8 mg/l.
So it seems that more time is needed to break chelates - but we can measure them. I don't have any other chelates. It would be fine to check also Fe-EDTA.
 

Allwissend

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Hello all,

I would like to report pretty good results using chelated micronutrients at what somewhat high levels, especially when we talk about chelated micronutrients.

The relevant bits about the tank,

  • high light (? Chiriros A601 plus - level 5 -15cm above water level with a 25cm water column), 6h per day
  • high CO2 yellow drop checker, about 1.7 pH drop
  • pure sand substrate ( no root tabs or other layers)
  • no fish, (phishless some would say), just snails and RCS - the suitability of this dosing still needs to be tested with various creatures.
  • hard european tap water GH 13 KH 10--- the main reason for chelated dosing
  • ph 8.36 outgassed, 6,68 fully gassed
  • a small jbl sponge filter and hydor powerhead... so pretty much no filter at all... no fish has its pros.
  • 50% weekly water change followed by dosing
The dosing, weekly totals created from 3x per day dosing via dosing pump (micronutrients and macronutrients dosed from separate bottles at separate times). Lab grade chemicals. Started this dosing on 20/01/2018.
w_dosing_chelates.PNG



All the plants grow, but I was able to grow some a lot faster and better under other setups. What was really surprising to me....

Althernathera reineckii mini
chelated-traces-Althernathera1.jpg


This plant has shown no twisting or crinkling on the leaves all this time.Grows solid. I also introduced a normal reineckii with similar results.

chelated-traces-Althernathera-2.jpg

Keep in mind this is about 1:2 in real life, so close to a real macro. I think this shows that it is possible to have high chelated micronutrients without Althernathera twisting and turning.

chelated-traces-Persicaria.jpg

Persicaria has solid growth, even the emersed growth remains good.

Another surprise:
chelated-traces-Prosepinaca.jpg

Prosepinaca palustris (source: Oliver Knott) is über fine but also extra green. Perhaps the floating plants in the tank create to much shadow.

Interested in what you think. Certainly can be improved and there is much more to test but hope this gives others courage to play with chelated micronutrients.

Furthermore, I was unable to replicate the results of Zervan using the same brand of iron test but using solutions of Fe-EDTA or Fe-HEDTA and distilled water. I compared the results after 5 minutes to 1h and 1day after the test (no UV exposure). No difference both by eye and by calculating Delta E.
 

toads74

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Looking good @Allwissend. Thanks for posting the data. Pardon my noobishness for a moment. :cool: Do you find that this tank needs that level of co2, or is it in excess of what should be needed?
 

Allwissend

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Hi @toads74, I would say by the end of the day it is a little more than needed,.just like all the other. But as there is no pH controler, the pH drop is lower when lights turn on. No fish has its advantages, but the snail and shrimp population produce a good deal of debris.
 

easternlethal

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So the problem here is edta Fe - IF your PH is much higher than 6.5 for any length of time. My tank for example is only under 6.5 during the photo period when the co2 is on. Overnight it degasses up to around 7.4. So for at least 14-15 hours every day it gets way above 6.5.
Sorry for the noob questions (and on this several month old point) - Your diagram shows that fe DTPA still seems to break at around 7.5 I think so is it really that much more effective than EDTA after overnight degassing? I tend to add FE after co2 is on for several hours so in that case would it matter whether it was dtpa or edta? And lastly, what would edta bind to after it breaks? P? If so should we just be adding P daily to compensate?
 

burr740

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Sorry for the noob questions (and on this several month old point) - Your diagram shows that fe DTPA still seems to break at around 7.5 I think so is it really that much more effective than EDTA after overnight degassing? I tend to add FE after co2 is on for several hours so in that case would it matter whether it was dtpa or edta? And lastly, what would edta bind to after it breaks? P? If so should we just be adding P daily to compensate?
DTPA only starts to separate from Fe at 7.5, The higher the PH climbs the more chelate is lost. But it's not like at 7.6 it's all separated, and its the same for EDTA at 6.5.

The extra point between 6.5 and 7.5 gives a pretty wide cushion for most of our tanks.

Mine for example at peak co2 is down around 6.3. Overnight it degasses to around 7.4-7.5. So it is only favorable for EDTA Fe for about 7-8 hours every day. The rest of the time it climbs further and further out of range. However it never falls out of range for DTPA Fe.

So it really just depends on individual PH levels which chelate is better. The further out of range the PH gets, the more separation occurs

Also it is important to note that EDTA only breaks loose from Fe around 6.5. To all the other micros it remains bound much higher, like way up into the 8s.

Free edta can bind to any free cation, this includes most other micros (except for B) and also Ca, Mg and K. It will not bind to N, P or S.

Ive seen where it has a strong affinity for Ca but not sure of any exact preference order.

Also is it necessarily a bad thing if it binds with something else? It's still available to plants, just takes a little more energy to get it.

The main issue is that you lose Fe. By lose I mean it becomes unavailable to plants. In a raw state Fe is highly reactive. It will quickly precipitate and/or bind with other things forming unavailable compounds like FePO4.

The other micros are not so volatile, which is why chelating is not so important for everything else. Fe is the main thing
 

Sepp0207

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Hello,

in my experience Mn is just as reactive as Fe. If I dose 0,075 ppm MnSO4 per day, there is nearly nothing left at the end of the day.

Greetings
Sebastian