Improved version of DS-10 by Ryuji Suzuki?

albada said:

A concentrate that gives XTOL-quality would be perfect for hobbyist-shooters like me, but no major manufacturer makes one.

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You might want to know that formulating a good developer is one thing, but formulating a good developer that can be prepared as a concentrated solution is a different thing.

When Silvergrain products were offered commercially, I was strongly advocating among those who were involved to offer powder solutions. They are more green (why do you want to burn extra fuel to carry water and heavier packaging for products that have shorter shelf life?), TSA-friendly, and better formulations can be made. All my proposals were roundly rejected because the consumers are obsessed with the notion of liquid concentrates are superior performers. At this point and time when majority of users are small volume users like you, I really think all powder formula make more sense.

Even if a small company made one, I wouldn't feel comfortable because: What happens if the little company closes? My developer vanishes. So I want the concentrate to either (1) be made by a large company, or (2) have a published formula so I can mix it myself (in case the company vanishes).

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You are assuming business people are rational. At this point and time, majority of smart business people already left, forced to leave and/or abandoned silver halide imaging industry. So the only players are the people with limited business expertise who are fighting for the few remaining pennies. They often don’t make rational judgments.

For hobbyist shooting, there is no problem mixing the sulfite separately, as you suggested, which makes designing a concentrate easier.

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Right. Or, as I said above, reconsider all powder formulation.

Did you try cysteine and discover it damages gelatin?

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How else would I know? Keep in mind photographic industry is very notorious for not disclosing anything useful unless it is absolutely required to get patents. Many patents have serious flaws but they do not disclose such things until they solve them, at which point they reveal the problem only as a basis for a new patent application. I’ve read MANY patents and repeated many examples given in the patents just to find out the limitation of their inventions. Haist’s books are largely compiled from benign published materials including patents, and the manuscript was betted by several Eastman employees just like the CIA and the state department redact documents they release.

Cysteine, thiourea, thiocyanate, etc. all have adverse effects on gelatin. This is largely pH and concentration dependent. But really, another problem with these agents is loss of speed with modern films. If you accept the loss of speed, you could achieve matching granularity by cutting development time or some other means. Some of these legendary "fine grain agents" actually make grains bigger with modern films, depending on the developer formula. Another problem with this type of agents is loss of accutance. If your objective is to achieve maximum enlargeability, it is not just granulrity that impose limitation. Besides, these agents also tend to produce strange sensitometric curves with some modern films, and also increase the tendency to cause silver stains such as dichroic fog. All these problems are not worth fighting for.

Alan Johnson said:

Tests on this line of ideas are not described here on APUG as far as I know.

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APUG didn't exist back then. Also, it is not a common practice to report negative results unless they resolve a controversy or something.

It would be interesting to know if you tried the grain solvent ammonium thiocyanate as it is available and not expensive.Particularly,will it dissolve in glycol,are there associated hazards and why it was not used.

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See my previous response.

Here’s a kicker.

In my routine practice, I used spent developer as the washing aid after through fixing and quick rinsing. As long as your fixing is complete, there’s nothing more to develop, so you can reuse sulfite-containing mild alkaline solution (that is, used developer) as a washing aid. You probably don’t need it to remove residual thiosulfate, but you do get significantly improved removal of sensitizing dyes, and save a lot of water and time.

I looked over my old lab notes. One thing I found to improve image quality is to use a mixture of triethanolamine, methyldiethanolamine, methylethanolamine, and dimethylethanolamine. The best proportion of the mix depended on the developer formula (mainly the pH factor). I would use these agents if liquid concentrate stock is to be prepared.

Ryuji said:

I looked over my old lab notes. One thing I found to improve image quality is to use a mixture of triethanolamine, methyldiethanolamine, methylethanolamine, and dimethylethanolamine. The best proportion of the mix depended on the developer formula (mainly the pH factor). I would use these agents if liquid concentrate stock is to be prepared.

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Wow! And these are only the chemicals that worked well for you, and not the many poor ones. You must have tried many different chemicals. Thanks for mentioning these. It's interesting that MEA and DEA are not in your list (but relatives are).

Ryuji said:

In my routine practice, I used spent developer as the washing aid after through fixing and quick rinsing. As long as your fixing is complete, there’s nothing more to develop, so you can reuse sulfite-containing mild alkaline solution (that is, used developer) as a washing aid. You probably don’t need it to remove residual thiosulfate, but you do get significantly improved removal of sensitizing dyes, and save a lot of water and time.

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If typical development is 7 min and fixing is 7 min, that's 14 min in an alkaline sulfite solution. Is that not enough to remove those dyes? Anyway, this is a clever idea.

Ryuji said:

When Silvergrain products were offered commercially, I was strongly advocating among those who were involved to offer powder solutions.

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For one-shot use, would a user measure a certain amount of powder from the container to develop a roll? A different amount of powder is needed for a stainless steel tank versus Paterson-4, and for 35mm versus 120. And one roll versus two rolls. A different amount of powder could be measured for each case.
My question is: How can we guarantee that the powder stays mixed well? I guess the user could shake the jar before measuring-out some powder, but I'm still not sure that coarse and fine powders would be mixed uniformly.

Also, acid touching alkali (as powders) can cause problems, and I read in Mason about some ways of dealing with them. XTOL fixed the problem by having two packets. What method are you thinking of?

A Merry Christmas to everyone!

Mark Overton

albada said:

Wow! And these are only the chemicals that worked well for you, and not the many poor ones. You must have tried many different chemicals. Thanks for mentioning these. It's interesting that MEA and DEA are not in your list (but relatives are).

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Not the *only* chemicals. There is always good old sulfite.

I tried a few pyrimidine (vitamin B) derivatives that worked well but too expensive for routine processing solutions. The ones that worked best were amino substituted at 2- and 4-positions. Those substituted only at the 2-position was ok as a developer additive but weak. Substitution at 4-position could be -OH. Incidentally, disubstituted pyrimidine was a decent developing agent. It would've made a decent press if I sold a developer using vitamins B and C as the developing agents, even at a price no one could afford, and hype it as "better than amidol and finer than glycin" and more exciting than Eikonogen or crap like that. People always like that kind of stuff.

I just checked. 2,4,6-triaminopyrimidine is commercially available for about $60 for 25g. This is a decent developing agent. You can dissolve a few grams of this with carbonate and make a slow working developer. A vitamin B developer.

I also tried imidazoles. They were more useful as a way to modify image tone and color than fine grain, though.

I used diethanolamine and it is okay in small quantities (a couple of grams per liter of working solution) but I wouldn’t use too much. Ethanolamine (monoethanolamine) - I didn’t like much. Same kind of problems as ammonium salts though less severe.

I did test a fair number of amines, because they could triple duty - as a pH buffer, chelator, and gentle silver complexing agent. I always had to blend two or more of them, because the one that’s best as the pH buffer for a target pH does not perform well for the other two functions. Some of these amines could have another duty of chelating calcium/magnesium from tap water. Ok, this is too much of my proprietary information.

Just in case someone tries to get ahead of me and get patent on this... because these agents are not listed in the prior art, I’ll also say this... the substitution on the nitrogen may be not limited to methyl group but it can be larger group, ethyl, etc. It is just that methyl version is cheaper and easier to get (and less smelly).

If typical development is 7 min and fixing is 7 min, that's 14 min in an alkaline sulfite solution. Is that not enough to remove those dyes? Anyway, this is a clever idea.

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You try once and you’ll know. Soaking in spent developer for another 5 minutes and then soak again in tap water and take a coffee break. You’ll get nice clean neg. Boston’s tap water has pH of 9.2 but I think a bit of sulfite helps this process.


See and discuss the rest of the stuff on the new thread I started.

Propylene glycol (PG) reduces developer-activity.

I was wondering why my concentrated developers were consistently less active than the identically-formulated ones directly mixed into water (without the PG carrier). Was I damaging the developers by heating the PG solution to 50C or with the extra handling? So I formulated one in water, developed a test-strip, then added 3.7% PG (by volume) and dev'd another strip. Significantly thinner, more than the extra 3.7% dilution could cause.

Here's the 1-liter version of the developer I tested. Its image-quality is virtually identical to XTOL, with the same dev-times. I added ingredients in this order:

Ascorbic acid ..................... 10.7 g
Sodium metaborate ............. 7.5 g
Sodium sulfite .................... 90 g
Phenidone .......................... 0.15 g (use a 1% solution with PG)

I'm hoping I can get the non-sulfite portion of this into a PG-concentrate suitable for 1+19 dilution.

If you add boric acid and boost the alkali a little to get the same pH, the resulting developer is a little less active. Any idea why? Does the resulting buffer-system hinder activity somehow?

Mark Overton

Did you check the pH of the comparable PG containing developer?

Organics can sometimes change pH or distort their measurement.

PE

albada said:

I was wondering why my concentrated developers were consistently less active than the identically-formulated ones directly mixed into water (without the PG carrier). Was I damaging the developers by heating the PG solution to 50C or with the extra handling? So I formulated one in water, developed a test-strip, then added 3.7% PG (by volume) and dev'd another strip. Significantly thinner, more than the extra 3.7% dilution could cause.

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Did you let the developer sit in a flask and see if there is any phase separation? (Like salad dressing made from oil and vinegar)

Photo Engineer said:

Did you check the pH of the comparable PG containing developer?
Organics can sometimes change pH or distort their measurement.

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Yes, using paper test-strips, I've been verifying a perfect color-match with unused XTOL. I'm using XTOL as an 8.2 buffer.
It's odd that 7% PG in a developer would have an obvious reduction in activity.
My last test boosted the PG from 3% to 7% with a noticeable drop in density. I wish I had a better understanding of the chemistry behind all this.

Ryuji said:

Did you let the developer sit in a flask and see if there is any phase separation? (Like salad dressing made from oil and vinegar)

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No, I tested the developer immediately after mixing, so neither concentrate nor working solution had a chance to settle. The working solution has now been sitting for hours, and a check a minute ago shows no separation.

I can only conclude that PG hinders development for some reason.

Mark Overton

Mark;

PG is not known as a development inhibitor unless it is at very high concentration and then it acts like most organic solvents by inhibiting many of the very polar reactions of development.

PE

Some exciting results!
I finally have a developer that can be used as a concentrate with 1+19 dilution (i.e., it's a 20x concentrate).
Compared to XTOL, it has: Lower contrast, same grain, very slightly better shadow-detail, same sharpness. In fact, I want lower contrast because I often shoot in contrasty situations, such as sun/shade, or harsh indoor lighting.

I took PE's hint that the path to better image-quality means longer dev-times, so I reduced the alkali some, yielding this concentrate which produces 1 liter of working solution:


I poured all the chemicals into the PG at the same time, instead of waiting for them to dissolve separately. It took about 30 minutes of constant stirring at 50C to get everything to dissolve. Jerry suggests letting the brew sit overnight at room temperature, and that it'll all eventually dissolve without heating. I did this last week and it worked, but this time I was impatient.
If I continue with this, I'll need to get a hot-plate/magnetic-stirrer combo.

To use, you must separately add 90 g/L of sodium sulfite to the distilled/deionized water first so it'll scavenge oxygen, and then add the concentrate. If sulfite is measured volumetrically (and thus less accurately), then the same graduate can be used for both sulfite and concentrate, because the user will measure powder first, then liquid.
Target pH is somewhere around 7.8-7.9 (I need a pH-meter!). Add 15% to XTOL's times, because this developer is similar to XTOL as it uses the same chemicals in similar proportions.
It has no chelating agents, so I suspect it can only be reliably used with distilled/deionized water, and I still wouldn't trust a working solution that's over a few hours old.

A question:
Why is the contrast lower?
I'll speculate that this developer has poor (nonexistent?) buffering because I removed the boric acid, and that causes the pH to drop more in dense areas, hindering development more in dense areas. That is, the poor buffering is causing compensation. Or am I off in the weeds about this?

Other comments or criticisms about this developer?

I know that to make this into a product, we'd want to incorporate a halide-solvent into the concentrate in order to eliminate the separate sulfite, and that lots of testing would be needed. I remember that Ryuji discovered a couple of films that worked poorly with his DS-10. That sort of knowledge only comes from thorough testing.

I enjoy this...

Mark Overton

Well, try using Potassium Sulfite.

If you want higher contrast try about 0.2 g/l of Phenidone.

I would also use it at 50 ml of concentrate to 19x water (950 ml) to make 1 L for a 1:19 mix. That is generally the convention. You are using 50 ml in 1L which is 1:20 but making a bit more. But that is fair, if that was your goal. It is just a bit more dilute.

Very nice. Remember though that lower contrast appears to lower grain and sharpness, so you may have more sharpness than you think!

PE

albada said:

I poured all the chemicals into the PG at the same time, instead of waiting for them to dissolve separately. [...]

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That’s a lot of work. Why don’t you leave it at a powder mix??

Target pH is somewhere around 7.4 (I need a pH-meter!). Add 15% to XTOL's times, because this developer is similar to XTOL as it uses the same chemicals in similar proportions.

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You apparently didn’t study my old posts. There is a very good reason why pH of DS-10 is 8.0, and XTOL is 8.2.

XTOL’s pH of 8.2 is probably the lowest pH where the developer can work reasonably well with all then-current films.

DS-10 chose 8.0 because I wanted slightly finer grain just for developing 400-speed films or faster (I almost always use a more accutance formula for 100-speed tabular grain films). DS-10 does not work (just don’t get enough density and contrast regardless of development time) with some films, all 100-speed or slower.

If you are doing pH of 7.4 that must be really well tested and come with a caveat. I think it is too risky to propose as a practical solution. But then how do you know pH without a good pH meter??

Also, how did you compare granularity and image quality if you developed the film to a different contrast index? It is an utterly unfair comparison. If you want lower contrast results, then you should compare yours against DS-10 further diluted or processed shorter or otherwise finished to the same CI. Any developer can produce better granularity if you terminate development prematurely.

It has no chelating agents, so I suspect it can only be reliably used with distilled/deionized water, and I still wouldn't trust a working solution that's over a few hours old.

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You’d better read my old posts. The main source of iron is the impurities in the sulfite stock. But then stainless steel used in tanks and reels does release some iron into water, although small, it can be readily detected.

A question:
Why is the contrast lower?

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Because you lowered pH and thus lowered the developer’s reduction potential.

I’ll speculate that this developer has poor (nonexistent?) buffering because I removed the boric acid, and that causes the pH to drop more in dense areas, hindering development more in dense areas. That is, the poor buffering is causing compensation. Or am I off in the weeds about this?

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Borate has nearly no buffering effect at pH of 7.4. It’s not the ingredients you used but what are actually present in the solution at the particular mixture, pH, temperature, etc.

Photo Engineer said:

Well, try using Potassium Sulfite.
If you want higher contrast try about 0.2 g/l of Phenidone.

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Does Potassium Sulfite boost contrast? Is it a halide solvent too? I did a brief search for this on apug.org, but didn't see anything definitive.

Photo Engineer said:

I would also use it at 50 ml of concentrate to 19x water (950 ml) to make 1 L for a 1:19 mix. That is generally the convention. You are using 50 ml in 1L which is 1:20 but making a bit more. But that is fair, if that was your goal.

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Actually, my goal is what you described: 1 part concentrate plus 19 parts water, making 20 parts (50ml + 950ml). I guess I should have been clearer.

But what do you suppose is reducing contrast? Compensation due to poor buffering?

Mark Overton

Ryuji said:

That’s a lot of work. Why don’t you leave it at a powder mix??

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Because the concentrate is more convenient for me. Although with only four chemicals, this developer would be easy to mix-when-using. BTW, I have no intention of making this a product for sale. It's for my own use, and helps me to learn about formulating developers.

Ryuji said:

You apparently didn’t study my old posts. There is a very good reason why pH of DS-10 is 8.0, and XTOL is 8.2.
XTOL’s pH of 8.2 is probably the lowest pH where the developer can work reasonably well with all then-current films.

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I probably read this and forgot it. Forgetting is one of my "core competencies".

This is interesting: I had no idea that some films won't develop properly below 8.0 or 8.2. I'm only creating this developer for myself, so I'll only test it with films I use, which are all 400-speed (TMY, TX). I suspect that this will be a niche developer. I'm measuring pH using two brands of test strips, so my measurements are probably +/- 0.2. That 7.4 might be 7.6.

Ryuji said:

Also, how did you compare granularity and image quality if you developed the film to a different contrast index?

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I'm judging granularity, contrast and sharpness using a pair of identical 22X loupes placed on the negatives. I quickly hop back and forth between them on the light-table. So all these judgments are qualitative and not quantitative. I'm aware that proper engineering requires quantitative measurements, but for preliminary personal work like this, qualitative is good enough for now. I'm a newbie still learning about all this, so I don't have the more costly lab equipment yet.

Ryuji said:

The main source of iron is the impurities in the sulfite stock.

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I remembered that one, and that's why I said I wouldn't trust working solution that's over a few hours old. So I'm not forgetting everything.

Ryuji said:

Because you lowered pH and thus lowered the developer’s reduction potential.

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And that makes me ask another newbie question (if you don't mind): I would expect reduced potential to reduce everything the same amount, making the negative uniformly thinner. But reduced contrast means highlights were reduced more than shadows. My question: How does reducing potential reduce contrast?

Anyways, thanks for your patience with my questions. I learn, and I try a developer like this one, and get surprising results, and learn more.

Mark Overton

albada said:

Does Potassium Sulfite boost contrast? Is it a halide solvent too? I did a brief search for this on apug.org, but didn't see anything definitive.



Actually, my goal is what you described: 1 part concentrate plus 19 parts water, making 20 parts (50ml + 950ml). I guess I should have been clearer.

But what do you suppose is reducing contrast? Compensation due to poor buffering?

Mark Overton

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Mark;

Potassium Sulfite is the same in activity as Sodium Sulfite but at a slightly higher concentration to compensate for molecular weight. It is however, far far more soluble. It can be purchased from the Photographers Formulary as a stock solution. That is where I get mine.

The low contrast may be due to pH, low Phenidone concentration (noted in my last post) or under development. The pH strips used by many can be off by quite a bit. They are good for an approximation but not for this type of critical work. Get a Hana meter for about $80. They use a Silver/Silver Chloride and Silver billet electrode set that is compatible with this type of work.

Best wishes in your work. You are doing quite well.

PE

albada said:

This is interesting: I had no idea that some films won't develop properly below 8.0 or 8.2.

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That is for developers that share the same basic design as XTOL or DS-10. It is not a universal law for all developers.

I'm measuring pH using two brands of test strips, so my measurements are probably +/- 0.2. That 7.4 might be 7.6.

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pH test strips are inherently inaccurate and an error of 0.2 unit is significant for a film developer.

I'm judging granularity, contrast and sharpness using a pair of identical 22X loupes placed on the negatives. I quickly hop back and forth between them on the light-table. So all these judgments are qualitative and not quantitative. I'm aware that proper engineering requires quantitative measurements, but for preliminary personal work like this, qualitative is good enough for now. I'm a newbie still learning about all this, so I don't have the more costly lab equipment yet.

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Then be careful when you report your findings. Using words like "better" based on subjective comparison without equalizing the conditions is only going to undermine credibility of the statement.

And that makes me ask another newbie question (if you don't mind): I would expect reduced potential to reduce everything the same amount, making the negative uniformly thinner. But reduced contrast means highlights were reduced more than shadows. My question: How does reducing potential reduce contrast?

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I think you need to do serious study of electrochemistry and modern theory of development process. It's not easy to describe this to people without proper background... First of all, you should make absolutely sure whether the speed (as measured 0.1d above base plus fog) did not change, as I bet it lowered. But then the development is not one process that uniformly progresses. It is a multi-step process. Developer parameters often affect each stage differently. Let's leave it at that for now, trying to add on a gross simplification is going to be wrong.

I goofed!

I re-measured, and the pH of that last developer is around 7.8-7.9, and I edited that posting to reflect this correction.
That's what I get for relying on my memory for an hour instead of writing things down immediately.

Anyway, PE suggested a Hanna meter, and I'll see if Grainger industrial supply (which is near me) has it in stock. If not, it'll be an internet order.

Mark Overton

Mine is Hanna HI-9125 but I replaced the electrode with a separate one that is refillable double junction type. Most kit comes with single junction or gel-filled electrodes. They are no good for photographic work. You want to make sure your electrode is "refillable" AND "double junction." You want to drain and refill the KCl solution in the electrode at the end of each shift, and calibrate the system at the beginning of each shift.

This unit is just fine: http://www.hannainst.com/usa/prods2.cfm?id=002003&ProdCode=HI 98127

I have 2 of them and have used them for years.

Here is more information: http://www.hannainst.com/manuals/manHI_98127_98128.pdf

There should be no problem with measuring developer or fixer pH.

For extra critical work I use a VOM with my own plated silver electrode and a triple junction electrode.

PE

Chemistry time!
Based on my rusty knowledge of chemistry, I think this is what will happen when ascorbic acid and sodium metaborate are mixed together:
They form sodium ascorbate, which we want. But will they also form that H2O above?
Will this reaction occur in the propylene glycol solvent? If so, it'll be adding 0.55 ml of water (per 50 ml concentrate), which is about 1%. That may not hurt, but I'd prefer the water-content be 0%. Also, what will those extra 2B and 3O form?

Photo Engineer said:

This unit is just fine: http://www.hannainst.com/usa/prods2.cfm?id=002003&ProdCode=HI 98127
I have 2 of them and have used them for years.

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I ordered one from Grainger, and will pick it up tomorrow. The in-person pick-up will allow me to verify on the spot that the electrode is wet.

Mark Overton

Go here: http://en.wikipedia.org/wiki/Ascorbic_acid and here: http://en.wikipedia.org/wiki/Sodium_ascorbate to see the structures of AA and Sodium Ascorbate. Your equation is not correct, as you cannot get free Boron and free Oxygen from this reaction.

Sodium Metaborate + AA = Sodium Ascorbate and Boric Acid which lowers the pH. By lowering the pH, if there is enough Borate or Metaborate and if the pH is high enough, the equillibrium shifts and the buffering ability of the ingredients kick in to maintain the pH as much as possible. That is a simple explanation of what is going on.

And, BTW, Borates are banned in many US Citrus states as Borates are toxic to Citrus trees.

PE

Photo Engineer said:

Sodium Metaborate + AA = Sodium Ascorbate and Boric Acid

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I analyzed the above equation, and got this:
Notice the extra 2 B's and 3 O's, which I combined into boron trioxide, which I doubt we'll actually get. Am I closer this time?

Do you know if this reaction would occur when mixed in the PG? Or does it only occur in water? I'm wondering if we actually get ascorbate in the PG.

Thanks as always,

Mark Overton

Mark;

This is a very complex reaction due to the presence of Borate which can make a variety of resultant anions. Don't worry about it. It is difficult for met to solve. I like easier equations. You are coloser, but the mixture will contain Ascorbates, Borates, Metaborates and the PG even makes some salts and esters with the materials present. You see, the Boric Acid will react with some of the metaborate and also with the OH ion present (being alkaline).

Just measure the pH and be reassured that if you adjust it to where you want it to be, things should work out.

Don't forget the toxicity of Boron containing salts to Citrus plants. IDK where you are located, but some of these salts are restricted in CA and FL.

PE