Post your DIY additives here!

[Randy Holmes-Farley]

That is fantastic, Randy!

This is why I want to compile a bunch of DIY supplements. The Mn and Mo I bought are around $16/ pound. Compared to the Triton supplements at $32 per 100mL or 1l bottle.

You could probably take a 10 grams out and give the rest away to a local reef club to share. :)

 

[csb123]

That’s the plan!

 

[ReefTeacher]

I make a number of my own supplements. Some are things I have had on hand, and I can dig out the recipes I keep in a file.

For Manganese, I have an old container of Potassium Permanganate that I used in my freshwater days with Fancy Goldfish. This is 34.76% Manganese so 1.00 g/L delivers 0.348 mg/mL. I used this as my Mn supplement for a few months, but it was messy and stained everything. So....Redox chemistry to the rescue!

I now dissolve the 100 mg of KMnO4 in just a few mL of water. I acidify with a few mL's of muriatic acid from the hardware store. Then add about 5-10 mL of 3% Hydrogen Peroxide from the drug store. It fizzes, releases a little HCl gas (don't breathe too close) and then it turns colorless! Mn+7 is reduced to Mn+2, such a faint pink you really can hardly see it. Dilute to 100g and you have your solution to dose.

BTW, some hints I use for making useful solutions: BUY A JEWELRY SCALE! you can get one on Amazon or eBay for about $20-$30 and it comes with weights for calibration. This is very helpful for weighing out small amounts. Mine reads down to the mg, but I tend to only trust it to the nearest 10 mg. Also WEIGH YOUR SOLUTION. I find with hobby grade equipment I can be far more consistent weighing 1 kg of solution rather than trying to measure 1 L. Since ppm is really a mass/mass ratio, we should be using a balance to measure the total solution mass. I find it much easier to get 3 sig fig's of precision this way.

 

[csb123]

All excellent ideas ReefTeacher!

 

[Randy Holmes-Farley]

It fizzes, releases a little HCl gas (don't breathe too close) and then it turns colorless! Mn+7 is reduced to Mn+2,

Wouldn't that be Cl2 gas? Not a good idea, IMO.

https://pubs.acs.org/doi/abs/10.1021/ja01447a005

 

[ReefTeacher]

Randy,

I don't think that reaction happens. Now I am probably farther from my chemistry than you, but I think you need to have the reaction in concentrated HCl for the liberation of Cl2 gas, but I don't remember and can't find a reference in a quick search right now. I do suggest that we first dissolve the KMnO4 in water, so the bit of acid is diluted. I also think we need to heat the concentrated HCl and permanganate for liberation of decent amounts of Chlorine gas, but that might just be a kinetic effect.

Secondly, if the chloride ion were oxidized, the reaction would proceed upon the addition of the acid. It does not, not even to the +4 state, which is insoluble. It is only upon addition of the peroxide afterward that the reduction occurs. I believe the reaction is:

2 MnO4-(aq) + 5 H2O2(aq) + 6 H+(aq)

2 Mn2+(aq) + 5 O2(g) + 8 H2O(l)

the oxygen gas bubbles out and the reaction is quite exothermic, hence the liberation of a little HCl gas. I do not smell Chlorine gas, I only smell HCl, but that is not a determinative test.

So even if the reactions were competing, the oxidation of the chloride ion must be very slow, or it would proceed on addition of the acid, and since we are working with a fraction of a gram, the amount liberated, in my experience, is negligible, or at least undetectable by my nose.

thoughts?

 

[Randy Holmes-Farley]

It sounded like it was pretty strong acid before you added the peroxide (maybe 6 M H+ if the volumes of muriatic acid and permanganate were equal). I'm not sure, but I'd expect some Cl2 can be formed then.

Then the peroxide solution was added. Guessing at the volumes, it looks like about another factor of 2 dilution of the acid, to maybe 3 M. Does 3 M HCl have fumes of HCl? Very little. About 1/12,000 as much as concentrated muriatic acid.

https://pubs.acs.org/doi/pdf/10.1021/i460001a002

I think you are correct that a lot of the gas was O2. I'm not sure what else you smelled, but I'd lean to Cl2 before HCL, but I cannot know with any certainty. :)

 

[Tmmste]

Dear chemists, I wonder if there is a possibility to add sodium molybdate and manganese sulfate/chloride to one of the following stock solutions:
solution 1 :
sodium hydroxide / sodium sulfate / disodium tetraborate / potassium iodide
Solution 2:
calcium chloride / magnesium chloride / strontiumchloride / potassium chloride

In the picture above you see the a DIY manganese solution. This stock solution consists of 1.25gr manganese sulfate (MnSo4*H2O) + 2,5 gr trisodium citrate + 1 ml vodka. this is a recipe (or ratio I should say) someone was using here in the Netherlands.

The citrate should prevent the manganese from oxidation.. however, despite the citrate, the solutions turned a beige color within a few days. I believe this is not a good sign...

probably it oxidised anyway? If the manganese sulfate would go with solution 1 (or will it react and form manganese carbonate or something like that?) do not know if I can add it just like this.. or would I just need to add the powder and not worry about oxidation? Or would it be better, for example, to look at manganese chloride. I looked into this, but couldn't find what I was looking for (like in this topic: https://www.reef2reef.com/threads/dosing-manganese-ii-chloride-tetrahydrate.257192/)

And, regarding the sodium molybdate, does it also risk oxidation or is possible to add this to solution 1 (or will it also react?). The goal is to stick with 2 stocksolutions and not having to add anything else seperately (as far as possible ofcourse.. ). I also would like to add iron to one of the 2 solutions, although I am sure iron will oxidise immediately if it is not chelated.. and the question remains if a chelated form (Fe-EDDHA e.g.), added to one of the stock solutions, would dilude/destroy the bond of the chelate... as turn iron into rust or precipitate out of the solution.

I am looking forward to any reply, please do not hessitate and feel free to participate.

 

[Tmmste]

Attempt 2: picture was not displayed in the previous post

 

[Randy Holmes-Farley]

I'm not sure citrate reduces chances for oxidation. Why do we think it would ? Chelated metals change oxidation state pretty easily. It may just make both the oxidized and reduced forms of some metals more soluble. :)

I think you'll have to experiment to see what may be stable in what, but I'd hypothesize that the molybdate may be soluble in the alk part and the manganese soluble in the calcium part.

 

[Tmmste]

I'm not sure citrate reduces chances for oxidation. Why do we think it would ? Chelated metals change oxidation state pretty easily. It may just make both the oxidized and reduced forms of some metals more soluble. :)

I think you'll have to experiment to see what may be stable in what, but I'd hypothesize that the molybdate may be soluble in the alk part and the manganese soluble in the calcium part.

I think I'll DIY a manganese / iron mix. just to provide some trace elements for the corals. I guess most will be consumed and benefit the scrubber. However, I do not want to use sodiumcitrate as it reduced no3 too much (I noticed no3 dropped to 1.0 and po4 incread to 0.06 and stunned the algea growth a bit)

I guess I'll have to experiment with EDTA/DPTA/EDDHA/HBED too see if I notice any significant difference.

 

[ReefTeacher]

I have not had good luck mixing Iron with other ions. Even at very low concentrations (eg. 20 ppm Fe) I get a noticeable amount of precipitate. I have not had trouble mixing other ions I am using, but I keep the iron separate and only make very small batches.

I am using an agricultural grade Iron (II) sulfate to make my solution. The solution is a very pale green, but the precipitate is a rusty red, which makes me think of Iron(III). This could be oxidation from the oxygen in the air, but what is it? Acid does not dissolve it, so it is not the oxide or hydroxide. I would expect Iron (III) sulfate to be soluble at that concentration (about 50 mg/L of anhydrous Fe2(SO4)3) so what is precipitating after a week or so?

 

[Randy Holmes-Farley]

I have not had good luck mixing Iron with other ions. Even at very low concentrations (eg. 20 ppm Fe) I get a noticeable amount of precipitate. I have not had trouble mixing other ions I am using, but I keep the iron separate and only make very small batches.

I am using an agricultural grade Iron (II) sulfate to make my solution. The solution is a very pale green, but the precipitate is a rusty red, which makes me think of Iron(III). This could be oxidation from the oxygen in the air, but what is it? Acid does not dissolve it, so it is not the oxide or hydroxide. I would expect Iron (III) sulfate to be soluble at that concentration (about 50 mg/L of anhydrous Fe2(SO4)3) so what is precipitating after a week or so?

What acid did not dissolve it?

 

[ReefTeacher]

HCL

 

[Randy Holmes-Farley]

How much?

I would have expected it to be iron oxide or hydroxide, so would expect dissolution.

 

[becks]

DIY coral snow - Calcium carbonate

Posted by Jedimasterben
https://www.reef2reef.com/threads/diy-kz-coral-snow-with-97-purity.211722/

 

[ReefTeacher]

How much?

I would have expected it to be iron oxide or hydroxide, so would expect dissolution.

I expected the same Randy, but it did not dissolve when I added muriatic acid, no matter how much I added. I wonder if my last test was contaminated with something. I just mixed up a fresh solution yesterday. I will keep more careful records about when the precipitate forms and if it dissolves in acid.

BTW, just for fun, I also tried Citric acid which I had lying around the house for cheese making. I thought maybe the acid and a chelating agent would help...no go!

 

[Tmmste]

@Dana Riddle have you, by any chance, done any research on chelates (to DIY iron and manganese as a trace element)? I have been reading through your articles but coudn't find anything about this. If you happen to know anything about this please share, thank you in advance Mr. Riddle.

 

[Dana Riddle]

I have not done any primary research, although I have used EDTA to chelate some metals. There are some that claim elevated iron concentrations can prevent coral bleaching, but my experimental protocol was faulty. <Sigh>

 

[Tmmste]

I have not done any primary research, although I have used EDTA to chelate some metals. There are some that claim elevated iron concentrations can prevent coral bleaching, but my experimental protocol was faulty. <Sigh>

Thank you for your very quick reply. I hope this is an interesting subject for the near future. I run on an ATS only (DIY), and I think dosing iron and manganese may also benefit the algae scrubber apart from the corals. Fe- nor Mn-citrate is an option as is will add a carbon source to the tank and it works against the algae scrubber (po4 increased as the hair algea growth stalled due to the lowered no3). So I am searching for this information on EDTA/DPTA/EDDHA/EDDHMA/HBED.. but couldn't figure it out. Ofcourse I asked the manufacturers how its done, but they will protect they business and not reply or talk around it... so I experiment now with 50% Fe-DPTA 50% Fe-EDDHA (Canna Fe+), I heard the weaker chelates like EDTA will not keep iron chelated for a long time as it will not hold due to the high pH. (which makes iron chelated with mono/tri sodiumcitrate (not sure if this is also the case with EDTA) essentially liquid phosphate remover....iron exposed -> oxidises -> rust -> reacts with phosphates)

Hopefully you can research this topic some day and reveal how its done and what works.. and what does not.. thank you for your time Mr. Riddle. Kind regards from the Netherlands, Tim.