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This is actually what Ive been tinkering with lately. Been using both for about 3 months. Most plants dont notice but it seemed to really help a couple species.

3x per week

Fe dtpa - .1
Fe gluconate - .06
Mn - .045
B - .037
Zn - .035
Cu - .0025
Mo - .0013
Ni - .0003
would you happen to have a list of which plants prefer the gluconate? I have a sneaking suspicion that glandulosa might be one but I haven't used that plant in a long time
 

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would you happen to have a list of which plants prefer the gluconate? I have a sneaking suspicion that glandulosa might be one but I haven't used that plant in a long time

Dont have a list but it seemed to particularly help some of the typical Fe indicator plants, limno sp for example. They can get right with lower overall levels. But I also tweaked B Mn and Zn down a little in the process. I'd done similar levels in the past with all dtpa, not a whole lot of difference really. I just suspect its more efficient, seems to work a little better but I havent tested stringently enough to say that for sure.
 

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Hello. I want to mix my own micromix, which reference ratio can be used in the mix? Micro will be doing on HEDP C2H8O7P2. I wonder if you've encountered it?
This is used as an anti-scalant and inhibitor in water treatment systems.
So basically an acid for cleaning.

You are trying to preserve your micro mix?
 

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Yesterday, I mixed up a new batch because I realized the last batch had precipitated something. I had added the ascorbic acid and 6.74g of CaCl2 a day after everything else due to a shipping problem. This time, I cut CaCl2 in half, to .325ppm, total 3.37g in 500ml. Still, 18 hrs or so later, the CaCl2 doesn't want to dissolve. Is there a trick to this? I'll keep shaking it up occasionally and see what happens.

Code:
In 500ml solution:

    10ml treats 35 gallons
    4.4ml treats 15.25 gallons
    2.6ml treats 9.25 gallons

         PPM    Grams  Source
acid     --     0.5    citric or ascorbic acid
Fe DTPA  .1     6.022  Fe DTPA 11%
Fe Gluc  .05    33.1ml Flourish Iron
B        .037   1.402  Boric acid H3BO3
Cl       .325   3.37   CaCl2 (+0.18ppm Ca)
Cu       .0025  0.065  CuSO4.5H2O
Mn       .045   0.917  MnSO4.H2O
Mo       .0017  0.028  Na2MoO4.H2O
Ni       .0007  0.021  NiSO4.6H2O
Zn       .04    0.746  ZnSO4.H2O
 

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Yesterday, I mixed up a new batch because I realized the last batch had precipitated something. I had added the ascorbic acid and 6.74g of CaCl2 a day after everything else due to a shipping problem. This time, I cut CaCl2 in half, to .325ppm, total 3.37g in 500ml. Still, 18 hrs or so later, the CaCl2 doesn't want to dissolve. Is there a trick to this? I'll keep shaking it up occasionally and see what happens.
The CaCl2 ion did dissolve, but its Ca atom precipitated to CaSO4. Molecule CaSO4 has very low solubility. Try kitchen salt NaCl instead.
 

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The CaCl2 ion did dissolve, but its Ca atom precipitated to CaSO4. Molecule CaSO4 has very low solubility. Try kitchen salt NaCl instead.
I dissolve CaSO4 every week without issues. Maybe you are thinking of CaCO3? CaCl2 is supposed to dissolve easily in water, according to the Internet. Also, zorfox didn't complain about solubility when I made my calculations.
 

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I dissolve CaSO4 every week without issues. Maybe you are thinking of CaCO3? CaCl2 is supposed to dissolve easily in water, according to the Internet. Also, zorfox didn't complain about solubility when I made my calculations.

Expanding upon @Edward’s comment, you are creating an insoluble level of CaSO4 in your mix. When you add CaCl, it dissolves quickly, which will free the Ca to bind with any SO4 in the mixture. Most of your metals have SO4 and the free Ca ion now binds to it, forming CaSO4, which quickly reaches an insoluble level. The result is CaSO4 precipitate.

You can test this by starting with your neat water (I assume you are using distilled or RO water) and add just the CaCl. Then, one-by-one, add the metal compounds containing SO4 and give them a few minutes between to check for precipitation.

It is better to not mix CaCl with any non-CaSO4 compounds.

Hey, why add chlorine?
The “Cl” in CaCl is the anion: chloride (Cl-), not chlorine. It is safe, unlike the chlorine element and plants benefit from it in low levels. I use a guideline of maintaining 3-7ppm chloride.
 
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Expanding upon @Edward’s comment, you are creating an insoluble level of CaSO4 in your mix. When you add CaCl, it dissolves quickly, which will free the Ca to bind with any SO4 in the mixture. Most of your metals have SO4 and the free Ca ion now binds to it, forming CaSO4, which quickly reaches an insoluble level. The result is CaSO4 precipitate.

You can test this by starting with your neat water (I assume you are using distilled or RO water) and add just the CaCl. Then, one-by-one, add the metal compounds containing SO4 and give them a few minutes between to check for precipitation.

It is better to not mix CaCl with any non-CaSO4 compounds.

The “Cl” in CaCl is the anion: chloride (Cl-), not chlorine. It is safe, unlike the chlorine element and plants benefit from it in low levels. I use a guideline of maintaining 3-7ppm chloride.
Thank you, @Deanna, this is the hard-hitting analysis I came to this thread for!

Now I have new questions:

1. It seems like all my other metal-sulfates were added in such small quantities that there wouldn't be enough free SO4 for all this Ca. Wrong? I haven't done actual chemistry braining in a lot of years.

2. What happens to the other metals now that Ca has stolen their SO4?

3. (or 2B) Is this bad? Can I just ignore the precipitated CaSO4 and move along?
 

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Thank you, @Deanna, this is the hard-hitting analysis I came to this thread for!

Now I have new questions:

1. It seems like all my other metal-sulfates were added in such small quantities that there wouldn't be enough free SO4 for all this Ca. Wrong? I haven't done actual chemistry braining in a lot of years.

2. What happens to the other metals now that Ca has stolen their SO4?

3. (or 2B) Is this bad? Can I just ignore the precipitated CaSO4 and move along?
Without doing the math, it’s hard to say - correctly - at what point there will be enough SO4 to combine with Ca to cause precipitation. It is, obviously, happening. By conducting the test I mentioned, you can see where the cutoff roughly exists.

Once the ions dissociate, the plants will, hopefully, consume them before they can oxidize. This is why we dose small quantities frequently (usually daily) of the DIY mixes, which are not chelated. If they were chelated, we wouldn’t have these concerns.

Since you are getting the Ca and SO4 elsewhere, then you can ignore the CaSO4 that has precipitated. If you are using a doser, it may accumulate and clog the line. If it is put into the tank, it will dissolve.

I also see that I may have misled on the Cl issue. When the CaCl dissolves the Cl2 actually dissociates into the two chloride ions and does not remain as elemental chlorine.
 
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