Another self-replenishing developer?

MattKing · Nov 7, 2021

X-Tol, like C-41 also has high activity. The difference is it is used at lower temperatures and it produces more development byproducts than C-41 per roll (likely a result of the design parameters for C-41).
That is why the 70 ml per roll advice is as useful as it is - the most important characteristic dealt with in the replenishment process for X-Tol is removal of byproducts. It's inherent activity means that even well used X-Tol is very, very similar in activity to fresh X-Tol, save and except for the effect of byproducts.
I was doing some arithmetic yesterday - a litre of X-Tol has more than enough chemical activity in it, but the byproducts do build up slowly but meaningfully.
Kodak's 70 ml per roll suggestion equates to about 13.5 rolls of developer byproduct per litre when the working solution is at a steady state. If you add another roll of byproduct to a litre of working solution, you need to discard 70 ml of that working solution to return that litre to a steady state.
If you are not using deep tanks - i.e. you are separating a portion of your working solution out to do the actual development - the rest of the working solution left in the bottle is already at steady state. As the goal in adjusting the replenishment of X-Tol is mainly to control the removal of excess byproducts, it is both simpler and easier to discard from the smaller batch that just developed film, before adding the remainder back to the rest of the working solution.
It is/was very different with more traditional replenished developers like D-76 and HC-110. With those developers, activity also varies as the developer is used, necessitating replenishers that are different than the normal working solution, as well as a need to entirely replace well used working solutions.

mshchem · Nov 7, 2021

I'm exhausted . I'm throwing my hat into Matt's ring, while not discounting Mr. Old Gregg.
I remember in a former life calculating equilibrium levels of plastic re-grind in a massive extrusion system. When we would start up with a new virgin material, we would extrude virgin, then scrap and re-grind this, I can't remember how many times. The point is we needed a material that had up to 50% re-extruded material in the extruded sheet we used to form the interior of a American style refrigerator.
The re-grind has an effect in color and physical properties.

I'm sure Matt's math is similar to show an equilibrium point.

I replenish when I use deep tanks, I don't with my Jobo. I have a lot of XTOL.

MattKing · Nov 7, 2021

X-Tol is really active. It is hard to exhaust. Running 15 rolls through a litre of it barely dents its activity. What it does do is build up byproducts, which tend to inhibit development.
The steady state equilibrium that works best is when each litre of working strength has in it the development byproducts of about 13.5 rolls. Even without replenishment, that litre is still able to fully develop new film with only a ten percent increase in time.
If you add one roll of byproducts to that one litre, you are up to 14.5 rolls worth of byproducts in that litre. You need to discard 70 ml of that to bring the byproducts down to the right level - 13.5 rolls worth. Some of that discarding happens because of carry-over. You need to manually discard the rest. And then you need to bring the volume back up to a litre, in order to restore the concentration of byproducts to the appropriate 13.5 rolls per litre.
The most practical way to make sure that exactly 70 ml is discarded, is to add 70 ml of replenisher to the balance of not recently used developer, and then top up the bottle with the recently used developer.

MattKing · Nov 7, 2021

Old Gregg said:
While the film is cooking in the tank, pour the replenisher into the working bottle, and then top it off with the developer from the tank, but always use the same amount of developer in the tank! Which means filling up 1L Paterson even if developing a single roll.

This is what I practice, and have always practiced. I regularly develop 1, 2, 3 or 4 rolls at a time, discard and replenish accordingly, and the results are consistent.
That approach reasonably mimics the way that deep tanks work, while still using a small tank.

Old Gregg said:
After the film is developed, mix the developer from the tank, the working bottle, and the required amount of replenisher together, and ONLY THEN drain whatever doesn't fit into the working bottle.

This doesn't make sense. You end up immediately discarding a portion of the replenisher you just added. You have to adjust the amount of replenisher/roll to take into account the size of your tanks and how many rolls you just developed. That amount of adjustment will differ with each change in the number of rolls.
What would make sense is: After the film is developed, mix the developer from the tank and the working bottle and then discard the necessary amount of developer to remove the right amount of byproducts. When the amount of byproducts is back to normal, you then add replenisher to bring the volume back to normal. This is the way that commercial labs do it (they take into account how much carry-over occurs when the calculate the amount discarded).

Raghu Kuvempunagar · Nov 7, 2021

From the datasheet:

"You can monitor replenished systems with KODAK Black-and-White Film Process Control Strips (CAT 180 2990). Adjust the replenishment rate up or down in 10 mL increments to keep the process on aim. Allow adequate time for the process to stabilize betweenr replenishment-rateadjustments. Use the lowest replenishment rate that will maintain process control."

MattKing · Nov 7, 2021

Old Gregg said:
Me too. Well, don't you think that mentioning the critical part of the procedure (constant tank volume) between runs is important?

I've frequently described my method in the past - always fill the one litre tanks I use (mostly).
It wouldn't make a difference though if I used the half litre tank to develop one or two rolls, because I would still be discarding the same amount of byproducts per roll.
And If I were to be so crazy as to get a larger tank to do more rolls, I'd just keep the ratios the same.

Donald Qualls · Nov 8, 2021

Bazza D said:
Was looking through Freestyle's website today and they have XT3 in stock, listed as new.

Aha! I haven't checked there recently, but their container must have come in. I've got two fresh bags of EcoPro at this time, however, so it'll likely be a while before I want/need to try XT-3 -- and since we don't (yet) have restrictions on borates here in the US, I'm likely to continue using EcoPro as long as it's easy and economical to get.

cjbecker · Nov 8, 2021

Donald Qualls said:
Aha! I haven't checked there recently, but their container must have come in. I've got two fresh bags of EcoPro at this time, however, so it'll likely be a while before I want/need to try XT-3 -- and since we don't (yet) have restrictions on borates here in the US, I'm likely to continue using EcoPro as long as it's easy and economical to get.

Are you using xtol and EcoPro interchangeably within the same replenished developer?

Donald Qualls · Nov 8, 2021

cjbecker said:
Are you using xtol and EcoPro interchangeably within the same replenished developer?

I've been tempted, but I won't. My Xtol working solution has suffered a little due to a change in strength (arithmetic error in final dilution to stock strength, as I have only a 4L container to mix in -- tank solution and one liter of replenisher came out a few percent strong, and the other two liters of replenisher are a corresponding few percent weak). Instead, I'll start fresh with two liter tank solution of EcoPro and three liters of replenisher, and I've got a second packet for next time. I'll likely stick with the EcoPro as long as it's readily available.

Mr Bill · Nov 8, 2021

Old Gregg said:
Agreed. "Byproducts per roll" is the best way to frame the caveat of this replenishing method. It is important clarification for folks who load two 120 rolls per reel, or who're generally not disciplined with tank volumes (easy to do if your tank is consistently oversized for your loads).

Also agree, as this will track closely with the exhaustion of the developing agent. The two go in step. But it is my guess that the concentration of the developing agent is the more significant thing. If the developer can just continue to be used and used, without being badly hurt, this suggests to me that the byproducts are not holding things back that strongly. I could be wrong - I've never studied the Xtol situation in any depth.

I DO see replenished Xtol as a fundamentally wasteful setup, throwing away such a substantial amount of excess volume. Perhaps this was the only way to make it work, I dunno. Or perhaps it was not deemed very worthwhile from a business standpoint, to have a separate, stronger replenisher.

I just continue to be a little surprised at how many people think this is a great thing, to be able to extend the use of Xtol like this. Needing "only" ~70 ml per roll of film. Whereas I know that C-41 developer only needs about 1/3 of that amount. Now, Matt seems to think that the b&w films simply release more byproducts(?). I don't think so, and I'm very doubtful evidence to this will found. I really think this is just an artifact of a self-replenished system - it is simply not optimized for replenishment.

I appreciate that this thread is not about C-41, and the Xtol folks are probably tired of hearing me talk about it. But C-41 developer, LORR, can adequately dilute out the development byproducts with only 25 ml of replenisher. How is this possible? It's not because there are less byproducts - it's because C-41 was designed to run with a significant amount of byproducts in it. The developer was tuned, as part of the design, to operate this way. So... when a roll of film is developed, and it releases byproducts (primarily bromide ion) into the developer, the 25 ml of replenisher is enough to dilute the byproducts back to the aim specs. As a consequence of this design feature, that 25 ml of replenisher must also be over-concentrated with developing agent... it must supply the same amount that was consumed. If C-41 developer was self-replenished it would take a much greater volume of replenisher to keep it going - in fact, the same activity level could not be maintained.

I am pointing these things out mainly because the OP was interested in having another self-replenishing developer. I'm guessing he thinks these are effective ways to do things. But as I just explained, the self-replenished system automatically produces much more waste material than a specially designed replenisher. In the case of Xtol vs C-41, the Xtol produces roughly 3 to 4 times more waste to be discarded (unavoidable carryout, due to the film being wet reduces the amount to be discarded). All of this waste is still almost perfectly usable developer, just gone to waste. (Maybe you have a niece or nephew who'd like to try single-use development at home - it would be perfect for them.)

On this note I promise to quit running down the self-replenished systems. Unless someone specifically asks. Aside from that I'm now gonna bow out of this thread. Adios gents.

Sirius Glass · Nov 8, 2021

Old Gregg said:
Maybe I should start adding the mandatory disclaimer every time this advice comes up: the routine you just described trades accuracy for convenience. It gets regurgitated here by non-practitioners every time Xtol-R comes up. Yet, it does not work if one's film volume is variable and the working bottle isn't big enough. That's because, if you follow this protocol, the activity of the final solution will be different based on how many rolls you just developed. The math is obvious (Sirius, with your background you should see it) and it bites quickly in practice when your volume drops from 4-6 rolls per run to just one.

This adds to @Mr Bill 's point... Replenishment, even with Xtol, is not as worry-free as adding "70ml/roll whenever you feel like it".

I use 1 liter bottles and I do not have any problems with the replenished bottles, while I use bladders["wine bags"] for the stock solution so that I can remove all the air from the stock bottles.

Sirius Glass · Nov 8, 2021

I worked through the calculus in detail based on what Matt and I stated and that aligns with what Kodak and others state. I always use about half a liter in the tank, add the 70ml/roll and top it off. I used calculus of variations [various used volumes] and after all the mathematics it still works out.

MattKing · Nov 8, 2021

Mr Bill said:
I DO see replenished Xtol as a fundamentally wasteful setup, throwing away such a substantial amount of excess volume. Perhaps this was the only way to make it work, I dunno. Or perhaps it was not deemed very worthwhile from a business standpoint, to have a separate, stronger replenisher.

It is kind of entertaining to see you referring to 70 ml as being a large volume. I think that probably surprises a few who have never worked around labs.
I may be wrong, but I have a feeling that stock X-Tol is actually far more dilute to start with than "stock" C-41 developer.
I think that what you are "throwing away" is actually more water, and less chemical.
That (until recently) $10 package of X-Tol that is sufficient to develop 70 rolls of film is aimed at a different environment than C-41 developer concentrates seem to be.
What it is aimed at is the environment where labs used to replenish D-76 or HC-110. By comparison, a bottle of HC-110 replenisher ended up being 5.7 litres of dilution B replenisher, and you only needed to use 22 ml of replenisher per roll.
HOWEVER, you had to discard all of your developer and start anew once you had processed 50 rolls of film through each litre of working solution. If you used a small volume of working solution (e.g. two litres) like many do here, that meant after just 100 rolls of film. That is less than one bottle of replenisher.
The other advantage of X-Tol, which may be the most important reason that it is different, is that the ascorbic acid based chemistry is relatively speaking far more environmentally benign than most of the alternatives. It wouldn't surprise me if that is the factor that is behind the relatively large replenishment volume.

John Wiegerink · Nov 8, 2021

Mr Bill said:
Also agree, as this will track closely with the exhaustion of the developing agent. The two go in step. But it is my guess that the concentration of the developing agent is the more significant thing. If the developer can just continue to be used and used, without being badly hurt, this suggests to me that the byproducts are not holding things back that strongly. I could be wrong - I've never studied the Xtol situation in any depth.

I DO see replenished Xtol as a fundamentally wasteful setup, throwing away such a substantial amount of excess volume. Perhaps this was the only way to make it work, I dunno. Or perhaps it was not deemed very worthwhile from a business standpoint, to have a separate, stronger replenisher.

I just continue to be a little surprised at how many people think this is a great thing, to be able to extend the use of Xtol like this. Needing "only" ~70 ml per roll of film. Whereas I know that C-41 developer only needs about 1/3 of that amount. Now, Matt seems to think that the b&w films simply release more byproducts(?). I don't think so, and I'm very doubtful evidence to this will found. I really think this is just an artifact of a self-replenished system - it is simply not optimized for replenishment.

I appreciate that this thread is not about C-41, and the Xtol folks are probably tired of hearing me talk about it. But C-41 developer, LORR, can adequately dilute out the development byproducts with only 25 ml of replenisher. How is this possible? It's not because there are less byproducts - it's because C-41 was designed to run with a significant amount of byproducts in it. The developer was tuned, as part of the design, to operate this way. So... when a roll of film is developed, and it releases byproducts (primarily bromide ion) into the developer, the 25 ml of replenisher is enough to dilute the byproducts back to the aim specs. As a consequence of this design feature, that 25 ml of replenisher must also be over-concentrated with developing agent... it must supply the same amount that was consumed. If C-41 developer was self-replenished it would take a much greater volume of replenisher to keep it going - in fact, the same activity level could not be maintained.

I am pointing these things out mainly because the OP was interested in having another self-replenishing developer. I'm guessing he thinks these are effective ways to do things. But as I just explained, the self-replenished system automatically produces much more waste material than a specially designed replenisher. In the case of Xtol vs C-41, the Xtol produces roughly 3 to 4 times more waste to be discarded (unavoidable carryout, due to the film being wet reduces the amount to be discarded). All of this waste is still almost perfectly usable developer, just gone to waste. (Maybe you have a niece or nephew who'd like to try single-use development at home - it would be perfect for them.)

On this note I promise to quit running down the self-replenished systems. Unless someone specifically asks. Aside from that I'm now gonna bow out of this thread. Adios gents.

WASTEFUL?????? I find it saves me some $$$ and I like the results. Unlike some folks I like Yankee and FR sheet film tanks for my sheet film since it helps prevent scratches I sometime got developing in trays. My fingertips are always numb from exposure to chemicals years ago so as careful as I am I still would have a sheet film corner gouge another sheet in the tray. Using the sheet film tanks works as well as my Stearman SP-445 tank. With the larger Yankee/FR tank I don't have to disguard large quantities like I would be using one shot Xtol. For me Xtol-R is a saver and not a waster And once you get used to the system it's a breeze. This is just one person's experience of course. JohnW

Mr Bill · Nov 8, 2021

MattKing said:
It is kind of entertaining to see you referring to 70 ml as being a large volume. I think that probably surprises a few who have never worked around labs.

John Wiegerink said:
WASTEFUL?????? I find it saves me some $$$ and I like the results

Yeah, I should have probably said this differently. As you (Matt) know, I have a big-lab background. Like in any decent sized business, you look at things in proportion. A couple percent of large amounts can be fairly large, itself. Now below is something I DID say earlier...

Mr Bill said:
Now, if one runs small enough volumes of the chems that the cost is insignificant to them, it doesn't really matter much what they do

My bone-to-pick with the wastefullness of Xtol is not with the users, themselves, but the fact that it seems like a badly designed replenished system. I say "seems" cuz I don't have inside knowledge, and perhaps there was no other way to do it. No one will probably ever know now (I think Silvia zawadzki passed away recently). But my experience with other systems, from C-22 on, other b&w systems, and even regenerating color developers, tells me that it was probably technically feasible. (I'd probably bet a lot of money on that.) But it wasn't done, for whatever reason. (I can make a lot of guesses.)

Anyway, the users of replenished Xtol seem to be pretty happy with it, and think it's a good deal. I see that Adorama is listing it for nearly $14 per package. So here's my question. For a given amount of film being developed by that package, wouldn't you rather only pay 1/3 of that, or around $5? Cuz that would be the rough equivalency. Of course, the price would never go down like that, cuz there's so much tied up in the distribution and that sort of thing.

But to me, it's sort of the principle of the thing - if you could make it to work with lower replenishment and less resulting waste, well, why not do it? Not enough pressure on Kodak at the time, maybe. Maybe it came as an afterthought; "now that we have this great new developer, is there a way to replenish it?" Clued-in labs would have probably used something else, based on the guidance of their Kodak TSR, the tech sales rep. The TSR would be in contact with other labs, has all the skinny on what works or not, and connections deep into Rochester. The TSR, ours, at least, could cross all the boundaries on behalf of their customers.

MattKing · Nov 9, 2021

I expect the savings that result from never having to replace the working solution more than make up for the higher cost.
And that $14 might be a fair bit more than a bulk buying commercial user would pay.
There might very well be some distinct financial benefits as well that come from the environmental benefits of using X-Tol.

MattKing · Nov 9, 2021

Old Gregg said:
re-citing random and irrelevant bits of it (Matt's habit) for no apparent reason

This tells me that you don't understand the datasheet.
All those bits tell us what we need to know about how experienced users can use X-Tol.

MattKing · Nov 9, 2021

Ignore the moderator status on this.
And perhaps you will find Z-133 more useful: https://125px.com/docs/techpubs/kodak/z-133-2003_03.pdf
Although it really doesn't tell you more than the X-Tol datasheet about how to approach replenishment.
Because the X-Tol datasheet is actually sufficient.

MattKing · Nov 9, 2021

I am sorry that your experience is inconsistent with what others have enjoyed.

Raghu Kuvempunagar · Nov 9, 2021

Old Gregg said:
Basically I am accusing you guys of misleading newcomers. I was one of them, I followed your advice last year, and it did not work.

Regarding the 'advice', are you talking about this thread?

removed account4 · Nov 9, 2021

Old Gregg said:
Another bullshit advice commonly stated here is to replenish with 70ml every two weeks even if you don't develop any film. I have no idea where it comes from, and it leads to steady developer activity growth over time. It reliably shows up in every Xtol-R thread on photrio and it is complete and utter bullshit. What's amusing is that it's never debunked, which tells me that I may be the only person here who actually uses replenished Xtol in meaningful volumes (not counting lab owners like Adrian who run a proper lab process and probably don't bother reading this stuff)

Most of the information on internet fora is opinion, it is 50% steeped in truth, and 60% not. It is sometimes from someone who knows what they are talking about, like Ron Mowrey, Gerald Koch, Pat Gainer or DF Cardwell and other times just "stuff" found other places and with words that got mixed up along the way and posted as fact / truth or just someone with no knowledge or expertise winging it. usually when I find advice given by someone, here or elsewhere in the inter web , I look at other things they have posted, I read comments that have to do with their posts and their responses, (cause sometimes people post stuff just to troll ) and I look at their photographs they have posted in some sort of thread or gallery to exemplify who they are and what they are talking about. all too often there are people on the internet who dispense advice all day long and either their work doesn't jive with anything they have dispensed, or they have no work online at all or its impossible to find because they a different user name on every forum they dispense advice on, so they are just an oracle whose advice to take at your own risk. Then after I homework I decide if they are full of crap and if it's worth wasting chemistry, film, paper and my time There have always been people who offer advice that sometimes isn't the best, that's the internet.
If it was me whose advice you read in any Xtol thread ( here ) going back to 2003, I haven't changed my opinion which is based on years of experience using gallons and gallons of Xtol with a variety of waters, films cameras, formats and exposure and agitation/processing methods, and that is use something else, its hands down the worst developer I have ever used. It isn't worth the effort of buying, mixing or diluting or replenishing. It is fun to mix part A and B though, I didn't mind that, its fun like the fizzy cocktail of mixing Ansco 130, or putting the Vit C in Caffenol C...

Sorry to read you got bad advice!
John

grain elevator · Nov 9, 2021

Old Gregg said:
The only reason I do this is because I like slightly more "tight" grain pattern of Xtol-R

Just an idea, have you tried fresh xtol with a pinch of KBr? Shouldn't that be the most significant byproduct? Or perhaps some other iodide and chloride too?

Mr Bill · Nov 9, 2021

Old Gregg said:
Another b******t advice commonly stated here is to replenish with 70ml every two weeks even if you don't develop any film. I have no idea where it comes from, and it leads to steady developer activity growth over time. It reliably shows up in every Xtol-R thread on photrio and it is complete and utter bullshit. What's amusing is that it's never debunked,...

I was gonna comment on this, but John (jnantz) said it a lot better than I would have.

Regarding things not being debunked, it seems to me a bit of an uphill battle with no real payback. Once the original idea has spread a little, and is becoming accepted, then the burden of proof seems to fall on the debunker, etc. So it's an extra effort to collect supporting data, then respond to multiple counters, and the reward is ... nothing.

There is quite a lot of information on this site that is not really right, but mostly not too harmful, so there's not that much motivation to argue against it. I'd put the "two-week replenishment" thing in this category. If someone wants to follow a certain "ritual, " or whatever you wanna call it, well, I'm mostly glad to let them.

Donald Qualls · Nov 9, 2021

Mr Bill said:
In the case of Xtol vs C-41, the Xtol produces roughly 3 to 4 times more waste to be discarded (unavoidable carryout, due to the film being wet reduces the amount to be discarded). All of this waste is still almost perfectly usable developer, just gone to waste. (Maybe you have a niece or nephew who'd like to try single-use development at home - it would be perfect for them.)

As the OP of this thread, I'm well aware that C-41 needs only a bit less than half the replenisher (at least with LORR chemistry) as Xtol; I use Flexicolor LORR for my color negatives. However, I'd been under the impression that B&W chemistry has trouble controlling byproduct buildup in low-volume replenishment (like that for Sprint Standard, for instance, with replenisher that's 10x as concentrated as the working solution, but otherwise identical, or with D-23/DK-25R), and B&W byproducts mostly tend to inhibit the activity of the developing agents. D-23 gets around this by including metaborate in the replenisher, thus leading to pH increasing with replenishment (which may be one reason for the rule of thumb limit on working solution life; you can't increase pH beyond a certain level with the same alkali in the replenisher). Xtol does it by "washing away" that 70 ml for every roll processed.

I do, however, like the idea of storing the discarded Xtol to use for one-shot processing; the discarded solution is "used once" stock solution which, for Xtol, would require no more than 10% increase in time vs. fresh stock solution -- and adjustment that ought to apply equally once diluted 1+1 or 1+2. My only concern with doing this is that I don't process a large volume of film, so I'd be concerned about the storage life of the "discarded" solution before I build up enough (250 ml, at least, to give a half liter after dilution) to use this way. Small volume means it's hard to eliminate air from the bottle, too.

removed account4 · Nov 9, 2021

Mr Bill said:
Regarding things not being debunked, it seems to me a bit of an uphill battle with no real payback. Once the original idea has spread a little, and is becoming accepted, then the burden of proof seems to fall on the debunker, etc. So it's an extra effort to collect supporting data, then respond to multiple counters, and the reward is ... nothing.

yeah ... It ends up a total black hole of time and energy. Its just a lot easier to realize who the people are whose advice is worth reading ( LIKE YOURS MR BILL ) and the advice from others whose words of wisdom are less valuable, all while making sure to only shake one's head, and doing nothing because it will only land one in hot water to be trolled or cause trouble for management.

michael_r said:
You fool!

Yea I know! LOL

Another self-replenishing developer?

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