hard water, soft answers

[David Lyga]

Given that Kodak Anti-cal is no longer living, is there an EASY solution to the query: How can hard water be softened so that when adding sodium carbonate it does not cloud up.

Specifically, can something be bought at a local supermarket or hardware store in order to allow such water to remain crystal clear after the carbonate addition? - David Lyga

 

[Rick A]

Why not just use distilled water, it's cheap. I pay .99/gallon at my the local grocery.

 

[jeffreyg]

Plus 1 for distilled water. Our house is on well water plus a softening system and I have a cartridge filter for my darkroom but I still use distilled water for mixing chemical concentrates (developer, fixer and photoflo). I use the house water to dilute for working solutions for paper and have never had a problem.

http://www.jeffreyglasser.com/

 

[David Lyga]

OK, that is feasible, but I wonder if there is an actual, and easily attainable, chemical that can be added. - David Lyga

 

[Bob Carnie]

Kodak Anticalcium #1 (Kodalk) was sodium hexametaphosphate. The Chemistry Store sells it so it is readily obtainable.

http://www.chemistrystore.com/Products-Chemicals_A_Z-1.html

I followed Geralds tip a few years back to tame some issues and it sure worked.

 

[Gerald C Koch]

There are several choices. Although you can't buy the Kodak product it was sodium tetraphosphate (also known as "Quadrafos"). Sodium hexametaphosphate (calgon) is an option, as is citric acid/citrates, or more expensive compounds such as EDTA etc.

You are right of course. My previous post was a scrambled mess, since deleted. The nomenclature of phosphates leaves much to be desired. It is easy to get lost, too many "metas, tetras and pyros. What I meant to say was that The Chemistry Store sells sodium tripolyphosphate STPP which can replace AntiCalcium #1 (sodium tetraphosphate) w/w. Some polyphosphates work better for calcium while others are better for magnesium, STPP works well for both. In addition Kodalk (sodium metaborate) used as an accelerator is also available among many other chemicals. Hope this gets things straightened out.

http://www.chemistrystore.com/Products-Chemicals_A_Z-1.html

 

[JW PHOTO]

Sodium tripolyphosphate STPP Vs EDTA Tetrasodium ? My water where I live is darn good right from the tap. The village water treatment system seems to work fine and I have no complaints, but my cottage in the north country is different. It's well water that's hard and has a fairly high iron content. I'm in my later years and find myself spending weeks at a time up there. I have cleared a room for a darkroom and want to do a my processing up there while there. Question is, which of the two is better for the water at the cottage and what's the usual dosage per liter of developer? I'd use distilled water, but I'm a good distance from any store which might have it and want to know just in case I would run out of distilled water.

 

[Gerald C Koch]

Iron really is not a problem for most developers and is a common contaiminant of sodium sulfite. The only exception would be for Xtol and other ascorbic acid based developers. EDTA cannot be used for these developers since it introduces its own problems. There are two choices use STPP or boil the water first. Boiling for five minutes and allowing the water to stand overnight will precipitate any calcium hardness. The softened water can be decanted or filtered off for use. The other option is to add 2 g of STPP per liter for low pH developers like D-76 and 4 g for higher pH developers like D-72.

 

[JW PHOTO]

Gerald,
Thanks for that info and the STPP method sounds like the answer for up to the cottage, but most of the time I only use distilled water for my developers anyway. Still nice to have a backup plan in case I run out.

 

[Gerald C Koch]

Hi Michael,

Sometimes it can be very difficult to winkle information from the net. I was hoping to get stability constants for both citric and STPP complexes. No luck. However after wading through dozens of hits for quack chelation therapy I did find that citrate forms a water soluble complex with calcium ions which appears to be rather stable. It would appear that sodium citrate could be used. However if no chelating agent is at hand and something must be bought I would go for the STPP instead. Just sort of a gut feeling as to the effectiveness of each. I saw many more hits for the use of EDTA or pyrophosphates like STPP than for citrate.

 

[Old-N-Feeble]

I bought a basic 5-stage reverse osmosis set for $86 delivered. I haven't tested it yet but I expect it'll work well enough. It's not pretty and has no faucet/valve but I don't need that for photography and gardening. I bought adapters for sink faucet and hose end for an additional $2 each. I didn't buy a flow restrictor because I can control flow with the upstream valves.

I realize this is not a chemical solution but I think it's better.

EDIT: My water is so bad that I added an inexpensive sediment filter before the RO setup. I got that at a local building supply for $15.

 

[Rudeofus]

Jerry, here is a table with complex stability constants for Calcium, EDTA and Citric Acid. Looking at the numbers, the Citric Acid Calcium complex looks very weak, and I'm not sure whether it would sequester Calcium reliably at pH 10-11.

Here is a brief overview of common chelating agents used in photography:

• Citric Acid: see above. Very weak Calcium chelating agent.
• Quadrafos, Hexametaphosphates etc. work well for Calcium, but hydrolyze easily at high pH --> unsuitable for long term storage of process bathes.
• EDTA: works very well for Calcium, reliable and stable. Poorly soluble at low pH, but at low pH Calcium is not an issue anyway
• Ryuji Suzuki played with TEA and Salicylic Acid to keep Fenton oxidation of Ascorbate under check, allegedly with mixed success.
  
• DTPA: works very well for Calcium, and also for Iron impurities. It's used in Xtol to keep Fenton reaction in check.
• Phosphonic Acid based chelating agents: ATMP, aka Dequest 2000/2006 is commonly used in color process liquids to sequester Calcium and Iron. HEDP, aka Dequest 2010 works well in the short term, but struggles with Calcium unless special Cations are added to the process liquid.

Sadly, DTPA, ATMP and HEDP are pretty difficult to get for amateurs.

 

[Gerald C Koch]

Jerry, here is a table with complex stability constants for Calcium, EDTA and Citric Acid. Looking at the numbers, the Citric Acid Calcium complex looks very weak, and I'm not sure whether it would sequester Calcium reliably at pH 10-11.

Thank you for this information which I will save. I remembered seeing a similar table but could not find it again. Both Yahoo and Google seem more intent on slanting your search towards selling rather than information.

Jerry

 

[Gerald C Koch]

I was disappointed that the Chemistry Store now sells only STPP. At one time they hade several phosphate chelating agent including the banished Calgon. If hard water is a problem I would suggest getting STPP now before it too is gone.

 

[JW PHOTO]

I already have enough EDTA and STPP to last me Jerry, but I'm curious as to why Calgon was banished. It sure doesn't seem to be one of those things that pose a high risk, but what do I know.

 

[Gerald C Koch]

I already have enough EDTA and STPP to last me Jerry, but I'm curious as to why Calgon was banished. It sure doesn't seem to be one of those things that pose a high risk, but what do I know.

I think that the use of Calgon was so wide spread it was banned over other water softeners. When phosphates get into bodies of water they act as fertilizer and encourage the growth of algae and other obnoxious weeds like water hyacinth and hydrilla. (Actually phosphorous is a major ingredient in most fertilizers.) Entire lakes in Florida and Georgia have been turned in plant soup choking out fish and other animals and good plants. Hydrilla fouls the props of motor boats.

Its selection might also be because it hydrolyses back to simple phosphates more readily than other pyro phosphates. Sometimes regulatory groups are a bit fuzzy in their reasoning.

So the story goes that the state of Florida tried to find a use for water hyacinth. One proposed solution was to dry it, chop it up, mix it with glue and make fiber board out of it. An engineer took a few sheets home and built a shed in his back yard. When the rainy season came the shed started to sprout.

 

[JW PHOTO]

I think that the use of Calgon was so wide spread it was banned over other water softeners. When phosphates get into bodies of water they act as fertilizer and encourage the growth of algae and other obnoxious weeds like water hyacinth and hydrilla. (Actually phosphorous is a major ingredient in most fertilizers.) Entire lakes in Florida and Georgia have been turned in plant soup choking out fish and other animals and good plants. Hydrilla fouls the props of motor boats.

Its selection might also be because it hydrolyses back to simple phosphates more readily than other pyro phosphates. Sometimes regulatory groups are a bit fuzzy in their reasoning.

So the story goes that the state of Florida tried to find a use for water hyacinth. One proposed solution was to dry it, chop it up, mix it with glue and make fiber board out of it. An engineer took a few sheets home and built a shed in his back yard. When the rainy season came the shed started to sprout.

That water hyacinth must be one tough SOB. Yes, I remember when they removed the phosphates from all laundry detergent. We have a small lake(150 acres or so) near us that was formed during the glacial period and is one of the bowl lakes surrounded by high ground. All around the lake are orchards and farm land so all the farm land gets drained into the lake. When I was a kid the lake was a very good fishing lake with fairly clean, clear water. Years later after I got out of the service I decide to take a girlfriend over there to fish. Well, you honestly could not see your hand 4" under the water. Algae was so thick the lake looked emerald green. It also smelled like a sewer from dead aquatic plants that had died because they couldn't get enough sun light. What had happened was a well known big farmer started raising tomatoes around the one whole half the lake. He had giant tanks that said Liguid Green on the side and they were full of liquid fertilizer. He used this on the tomatoes and every time it rained the runoff would flood the lake carrying the Liquid Green with it. I don't have to tell you what happened. I don't know if the State of Michigan stepped in or not, but there are no tomato plants there now and the lake is almost back to normal. So I do understand what phosphates can do. I just wouldn't have thought Calgon would have been much of an impact.

 

[Rudeofus]

I don't know where the notion comes from that Calgon has been banned anywhere. In Europe I can get it trivially from Fototechnik Suvatlar, and that same chemistry store which has been mentioned here in this thread seems to carry it under the name Sodium Hexametaphosphate.

 

[pdeeh]

Like so many things, it is a misunderstanding of a different issue.
Many phosphates have been removed from large scale use (e.g. in washing powders and other cleaning products) because of the negative environmental impact.
That's just not the same as "being banned".

 

[Alan Johnson]

I believe that in the UK and possibly Europe ebay still sells sodium hexametaphosphate, formerly known as Calgon, but the stuff now sold under the name Calgon is an insoluble zeolite which softens water by ion exchange.

 

[fdonadio]

(...) sodium tetraphosphate (also known as "Quadrafos").

(..) Calgon (...) under the name Sodium Hexametaphosphate.

Kodak Anti-Cal #4 (ATMP pentasodium salt) aka Dequest 2006 (...).

Is there a list of these trademarks/names and their real components here at APUG?

I know Metol and Elon are trademarks for p-aminophenol sulphate (or something resembling that), but I always ask myself what's really in Kodak Anti-foggant AF-2000, for example.

It would be cool to have everything in one place.


Cheers,
Flavio

 

[Rudeofus]

Is there a list of these trademarks/names and their real components here at APUG?

Kodak is not overly eager to disclose the exact composition of their proprietary products, so don't expect such a list to appear anywhere, at least not a complete one.

but I always ask myself what's really in Kodak Anti-foggant AF-2000, for example.

In order to keep this thread on-topic to the extent possible, I added an article about (there was a url link here which no longer exists) to the articles section.

 

[fdonadio]

Thanks, Rudeofus, for the resource. Very nicely explained. I didn't find a way to leave a comment there, but I'll send you a private message about it.

I only talked about AF-2000 as an example.

What I meant is a list of the stuff we know the composition (or at least the most important compound) for sure, like the ones mentioned in this thread and others: Anti-Cal #1 and #4, Calgon, CD-3, CD-4, Dequest 2000/2006/2010, Elon, Kodalk, Quadrofos, Metol...

IMO, such a list would make it easier for people to find the chemicals, especially when shopping at non-specialized stores.


Cheers,
Flavio