Ion-exchange resin
- Thread starter ubr0ke
- Start date
Hello,
can you please tell us if it will affect plants/fauna in a hazardous way ?
i'm talking sodium to ca, mg exchange resin.
thank's in advance.
can you please tell us if it will affect plants/fauna in a hazardous way ?
i'm talking sodium to ca, mg exchange resin.
thank's in advance.
Heresy It May Be, But Water From Water Softeners Is Generally Okay
Hi,
The amount of sodium added by ion exchange is directly proportional to the hardness of the water being “softened.”
Water hardness is expressed milligrams per liter as calcium carbonate (mg/l CaCO[SUB]3[/SUB]) or grains per gallon (gpg) CaCO[SUB]3[/SUB]. Each grain per gallon is about 17.1-mg/l or (ppm). The exchange rate is about 2.14:1 CaCO[SUB]3[/SUB]: Na.
So if you have moderately hard water of 5-gpg or about 86-ppm CaCO[SUB]3(eqiv)[/SUB] your water softener will add about 40-ppm Na.:wink-new:
Biollante
Hi,
The amount of sodium added by ion exchange is directly proportional to the hardness of the water being “softened.”
Water hardness is expressed milligrams per liter as calcium carbonate (mg/l CaCO[SUB]3[/SUB]) or grains per gallon (gpg) CaCO[SUB]3[/SUB]. Each grain per gallon is about 17.1-mg/l or (ppm). The exchange rate is about 2.14:1 CaCO[SUB]3[/SUB]: Na.
So if you have moderately hard water of 5-gpg or about 86-ppm CaCO[SUB]3(eqiv)[/SUB] your water softener will add about 40-ppm Na.:wink-new:
Biollante
A Map... 1 GPG is about 17.1-ppm
Hi,
I meant to include this map from Morton salt.
It is very generalized and I didn't see one for Canada off hand.
Your local water authority ought to have information on hardness.
Also remember that the ion exchange is far less than 100%, so it is actual amount of sodium is less.
http://www.mortonsalt.com/soft/sofisoft.htm
Biollante
Hi,
I meant to include this map from Morton salt.
It is very generalized and I didn't see one for Canada off hand.
Your local water authority ought to have information on hardness.
Also remember that the ion exchange is far less than 100%, so it is actual amount of sodium is less.
http://www.mortonsalt.com/soft/sofisoft.htm
Biollante
But you may want to check conductivity anyway if you have soft water fish (since it plays on the response but wasn't touched in the sparse query or follow-up). Although it may not add much physical salt, sodium ions are quite conductive and conductivity can rise by more than an order of magnitude. And conductivity leads to an almost direct relationship to gauging osmoregulation.
Usually not a great deal when you just consider housing the fish, but it could prove rather annoying if you try to breed them...
Usually not a great deal when you just consider housing the fish, but it could prove rather annoying if you try to breed them...
Huh?
Hi,
I am not sure I understand either the conductivity or osmotic pressure concern.
By definition when we reduce the “hardness” of the water, we are reducing the conductivity, total dissolved solids (TDS) and osmotic pressure.:gw
In the example I used in post #4, the conductivity went from 0.000134-[SUP]mho[/SUP]⁄[SUB]cm[/SUB] to 0.0000625-[SUP]mho[/SUP]⁄[SUB]cm[/SUB] (134-[SUP]µS[/SUP]⁄[SUB]cm[/SUB] to 62.5-[SUP]µS[/SUP]⁄[SUB]cm[/SUB]), TDS went from 86-ppm to 40-ppm and osmotic pressure from 0.040038-bar to 0.039538-bar (assuming 25C).
Biollante
jaafaman;78249 said:
Hi,
I am not sure I understand either the conductivity or osmotic pressure concern.
By definition when we reduce the “hardness” of the water, we are reducing the conductivity, total dissolved solids (TDS) and osmotic pressure.:gw
In the example I used in post #4, the conductivity went from 0.000134-[SUP]mho[/SUP]⁄[SUB]cm[/SUB] to 0.0000625-[SUP]mho[/SUP]⁄[SUB]cm[/SUB] (134-[SUP]µS[/SUP]⁄[SUB]cm[/SUB] to 62.5-[SUP]µS[/SUP]⁄[SUB]cm[/SUB]), TDS went from 86-ppm to 40-ppm and osmotic pressure from 0.040038-bar to 0.039538-bar (assuming 25C).
Biollante
By definition, Total Dissolved Solids is a measure of all dissolved molecules and ions as well as colloidal suspensions within an aqueous solution while Total Hardness is a measure of the divalent metallic ionic Molarity present in the solution. Since we are merely trading out divalent metallic ions for monovalent metallic ions while maintaining charge balance, I do not understand the assumption that TDS reduces with TH in the case of a salt-based DI unit.Biollante;78288 said:
For the same reason you provided the Morton chart, we can only make assumptions as to the starting and ending characteristics of the problem that might not bear fruit on the poster's situation. The OP hasn't even stated whether or not the supply is municiple or from a well. The only information we can glean lies within the OP's profile, which places the location as Edmonton and that the OP is a De-water tech (what is that, exactly?) because the question was posed in the simplest of forms without any background whatsoever.
In this case, we are exchanging Ca[SUP]2+[/SUP] and Mg[SUP]2+[/SUP] ions for two Na[SUP]-[/SUP] ions based again on assumptions, not knowing if Iron or any of the other TH components are present, but since we are dealing with a salt-based DI then it is fairly safe to assume that only the readily-formed chlorides within the exchange medium are affecting but the calcium and magnesium components, with the preponderence most likely to the calcium. But as we are dealing with a salt-based DI, then the salt most likely used is Potassium as many manufacturers choose this over Sodium chloride in order to decrease Sodium exposure for the sensitive.
Calcium has a thermal conductivity of 201 Wm[SUP]-1[/SUP]K[SUP]-1[/SUP].
Potassium has a thermal conductivity of 102.5 Wm[SUP]-1[/SUP]K[SUP]-1[/SUP].
So if we are indeed exchanging for Potassium then conductivity would drop a bit as Potassium has only about 80% of Calcium's ionization energy.
But...but if the DI is Sodium based, then we're looking at a thermal conductivity of 142 Wm[SUP]-1[/SUP]K[SUP]-1[/SUP], a 40% increase in conductivity to more than negate the difference in ionization energies between Sodium and Calcium.
Additionally, you provided an example based on an ambient of 25C, a reasonable assumption based on what is probably the majority of cases with community or planted aquaria. There are, for example, many soft water fish that prefer much higher temps. My main room has a heavily-planted, CO[SUB]2[/SUB]-enriched tank full of a dozen Dicrossus filamentosus, a half-dozen Otocinclus affinis and a dozen-and-a-half Corydoras habrosus at 31C and about 2dH (50-50 mix of tap and RO). Conductivity generally increases with temperature, and in a lot of cases actually increases with a drop in Molarity. As you can see in this simplistic chart from Wikipedia, the difference between 25C and 31C at lower Molarities can account for a 17% increase in conductivity were the solution straight Potassium chloride.
The two biggest obstacles to breeding softwater fish outside of lighting are tanin concentrations and osmotic regulation. Too much tannin will harden the egg membrane to the point of trapping the emergent fry within, and an increase in osmotic pressures due to salt content will essentially "dessicate" the egg as water moves from the egg to the environment.
Either TFH or FAMA (I'm thinking FAMA) ran an article in the 1998-1999 time frame on the effects of salt-based DI exchange on different localities which was both quite revealing and very much more detailed. I will try to track down the specific article, but I can't garantee success in the search.
So, on the basis of so many assumptions as to the starting and ending conditions I'm just not comfortable with the idea of such a broad generalization even though it applies to your own specific case...
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Sorry Abiout Running Over Your Dogma
Hi,
Okay…
The original post asked, “Does ion-exchange resin affect tds? lower?..”
Post #2 said, “It may lower TDS, it'll remove hardness etc.”
Albu81 in post #3 asked about the effects of Sodium resulting from the ion exchange that is an “ion exchange.”
My bad, in thinking perhaps the real question was the use of ion exchange resin. I am aware a number of manufacturers are selling resin-based ion exchange in tank filters.
Post #6, the discussion expands to include “conductivity” and soft water fish.
The questions were about sodium, so I calculated for sodium, using the same amount of potassium in the exchange indeed results in less softening, I have no idea what that has to do with the amount of sodium added and amount of reduction in TDS, conductivity or anything else, do to sodium.
So muddy away it changes nothing.
I understand that the idea of using “softened water” from a (gasp!) water softener is going to offend the sensibilities of the orthodox repeaters of the dogma. I understand that for many this is heresy.
The advantage of generalization, including, by the way the use of “equivalents” such as CaCO[SUB]3[/SUB] for “hardness,” the “generalization” (we were not speaking of a specific case after all) allows us to move to the specific.
I stand my statements.
I withdraw from further discussion of religious dogma.:nonchalance:
Biollante
Hi,
Okay…
The original post asked, “Does ion-exchange resin affect tds? lower?..”
- The answer is yes, to both.
Post #2 said, “It may lower TDS, it'll remove hardness etc.”
- My answer it is correct it will remove hardness, therefore also definitely TDS.
Albu81 in post #3 asked about the effects of Sodium resulting from the ion exchange that is an “ion exchange.”
- With no specifics, I was using average or general terms that are indeed arbitrary.
- The use of the moderately hard water was entirely arbitrary.
- Likewise, the use of 25C was arbitrary since it is a temperature dependent equation the precise answer will change with temperature, the general answer is still illustrative.
My bad, in thinking perhaps the real question was the use of ion exchange resin. I am aware a number of manufacturers are selling resin-based ion exchange in tank filters.
Post #6, the discussion expands to include “conductivity” and soft water fish.
- The water is softer (water softener) therefore the soft water fish ought to be happier.
- The effect of conductivity is predictable and can be calculated.
- The effect of the specific action is independent of other conditions.
- The added softened water will dilute or soften (clear) the water in a separate predictable way.
The questions were about sodium, so I calculated for sodium, using the same amount of potassium in the exchange indeed results in less softening, I have no idea what that has to do with the amount of sodium added and amount of reduction in TDS, conductivity or anything else, do to sodium.
So muddy away it changes nothing.
I understand that the idea of using “softened water” from a (gasp!) water softener is going to offend the sensibilities of the orthodox repeaters of the dogma. I understand that for many this is heresy.
- I am okay with that. It will not surprise me in the least if anyone produces a copy of FAMA or TFH defending the orthodoxy.
- It does not change the arithmetic. T
- he issue of sodium added as a result of deionizing resin is a little different in that any sodium added back will reduce the purity of the deionized water, effectively ionizing the water.
The advantage of generalization, including, by the way the use of “equivalents” such as CaCO[SUB]3[/SUB] for “hardness,” the “generalization” (we were not speaking of a specific case after all) allows us to move to the specific.
- If the permanent hardness were 8-dGH and the actual temperature is 22.37 C we can calculate by the same method.
- The result is that the water will be less conductive and have lower TDS and
- depending on the conditions of the water to which it is added will be softer or harder by that amount.
I stand my statements.
I withdraw from further discussion of religious dogma.:nonchalance:
Biollante
Nice to know, Biollante.
No discussion, then - I'll just stand by 45 years' experience with soft water and you can keep your "anti-dogma" and leave things at that...
EDIT -
Just realize, though, that you just blew a chance to educate someone, for what it's worth...
No discussion, then - I'll just stand by 45 years' experience with soft water and you can keep your "anti-dogma" and leave things at that...
EDIT -
Just realize, though, that you just blew a chance to educate someone, for what it's worth...
Last edited by a moderator:
Yes I am from Edmonton Alberta and I was a de-water tech. Which has nothing to do with my question. De-watering for those who are interested is a process of lowering the water table in an area so a safe, dry excavation can be achieved.
I was asked on another site whether using ion-exchange resin would increase tds, I didn't know the answer, so I decided to ask here. The one who had the question was concerned about Rams that continued to die in our tap water and was looking for a solution without having to purchase an RO system. I have a feeling tank parameters have more to do with the death's then our tap water, since I keep a few rams without any issues.
Anyways...
The water parameters in question can be found here
http://www.epcor.ca/en-ca/Customers/water-customers/water-quality-reports/Documents/112011_211.pdf
I was asked on another site whether using ion-exchange resin would increase tds, I didn't know the answer, so I decided to ask here. The one who had the question was concerned about Rams that continued to die in our tap water and was looking for a solution without having to purchase an RO system. I have a feeling tank parameters have more to do with the death's then our tap water, since I keep a few rams without any issues.
Anyways...
The water parameters in question can be found here
http://www.epcor.ca/en-ca/Customers/water-customers/water-quality-reports/Documents/112011_211.pdf
More of Something is, Well, More, Less Isn't
Hi,
Pretty much, what I mean by dogma…
Does the fact that I am in my 56[SUP]th[/SUP] year of keeping fish, much of the time with plants, mean that I am right not because the arithmetic says so, but because I have been at it longer than you?
No doubt, about it this adding and removing things from water can be confusing but when taken systematically things can be understood and modeled.
If I add warmer water to cooler water, the result will be a greater amount of warmer water. (Generalization.)
If I add 1-liter of 35C water into 10-liters of 22C water, we will have 11-liters of water that is about 23.18C. (Specific yet arbitrary example.)
Yes, the amount of water is arbitrary and you might well argue that your tank has 189-liters and is only 20C so that it is not going to be true for you since the answer is too general.
All day long, we can try to confuse the issue by talking about
A rule of life; if you add something you have more, if you subtract something you have less.:glee::cower:
There is nothing wrong with adding specifics; it is trying to win an argument with a storm of irrelevancies that I find galling.
Biollante
ps. If you want to learn, learn if not...
Hi,
Pretty much, what I mean by dogma…
Does the fact that I am in my 56[SUP]th[/SUP] year of keeping fish, much of the time with plants, mean that I am right not because the arithmetic says so, but because I have been at it longer than you?
No doubt, about it this adding and removing things from water can be confusing but when taken systematically things can be understood and modeled.
If I add warmer water to cooler water, the result will be a greater amount of warmer water. (Generalization.)
If I add 1-liter of 35C water into 10-liters of 22C water, we will have 11-liters of water that is about 23.18C. (Specific yet arbitrary example.)
Yes, the amount of water is arbitrary and you might well argue that your tank has 189-liters and is only 20C so that it is not going to be true for you since the answer is too general.
- I would answer that by the same process (equation)
- we find that 1-liter of 35C water added to 189-liters of 22C water
- will result in 190-liters 22.068C water.
All day long, we can try to confuse the issue by talking about
- barometric pressure or
- specific gravity or
- ambient temperature,
- each factor adding specificity (and complexity) that can be dealt with by increasing the specificity of the equation, or series of equations.
A rule of life; if you add something you have more, if you subtract something you have less.
:glee::cower: There is nothing wrong with adding specifics; it is trying to win an argument with a storm of irrelevancies that I find galling.
Biollante
ps. If you want to learn, learn if not...
Still Yes TDS Will Be Reduced, But Not Enough
Hi,
The short answer is that ion exchange resin will soften water, specifically lower the Calcium, which makes up [SUP]2[/SUP] ⁄[SUB]3[/SUB] of the hardness and the other [SUP]+2[/SUP] valance metals that make up the other [SUB][SUP]1[/SUP] ⁄3[/SUB].
The total hardness removed will be replaced by about [SUP]1[/SUP] ⁄[SUB]3[/SUB] as much Na[SUP]+[/SUP] or [SUP][SUB]1[/SUB][/SUP]⁄[SUB]2[/SUB] as much K[SUP]+[/SUP] so the net reduction in TDS will be [SUP]2[/SUP]⁄[SUB]3[/SUB] to [SUP]1[/SUP]⁄[SUB]2[/SUB] the portion of TDS resulting from the total hardness.
Since as an eyeball estimate it appears that 86.5% of your TDS is from total hardness in a perfect world ion exchange using sodium would reduce TDS by 57% (from your monthly average of 200-ppm to 85-ppm), with a corresponding increase of sodium from 5.6-ppm to about 59-ppm.
Biollante
[/FONT]ubr0ke;78319 said:
Hi,
The short answer is that ion exchange resin will soften water, specifically lower the Calcium, which makes up [SUP]2[/SUP] ⁄[SUB]3[/SUB] of the hardness and the other [SUP]+2[/SUP] valance metals that make up the other [SUB][SUP]1[/SUP] ⁄3[/SUB].
The total hardness removed will be replaced by about [SUP]1[/SUP] ⁄[SUB]3[/SUB] as much Na[SUP]+[/SUP] or [SUP][SUB]1[/SUB][/SUP]⁄[SUB]2[/SUB] as much K[SUP]+[/SUP] so the net reduction in TDS will be [SUP]2[/SUP]⁄[SUB]3[/SUB] to [SUP]1[/SUP]⁄[SUB]2[/SUB] the portion of TDS resulting from the total hardness.
Since as an eyeball estimate it appears that 86.5% of your TDS is from total hardness in a perfect world ion exchange using sodium would reduce TDS by 57% (from your monthly average of 200-ppm to 85-ppm), with a corresponding increase of sodium from 5.6-ppm to about 59-ppm.
- I will run the actual numbers tomorrow, it takes me a little bit of time, and the above numbers are “eyeball” approximations.
- Which of course means some butt-head will jump in screaming that I forgot to include this or that part per trillion.
- Reverse osmosis is almost certainly going to be part of the solution if Mikrogeophagus ramirezi are to be successfully raised with that tap water.
Biollante
Perhaps you can explain to this butt-head the methodology behind your math?
Using CaCO[sub]3[/sub] as a base, calcium's AW is approximately 40% of the molecule, meaning it's also 40% of the 88 ppm or about 36 ppm out to 80 ppm of the 200 ppm range extent.
Your 2.14:1 stated ratio appears to be a swap on mass, as you're exchanging 2x22 wt ions of sodium for each 40 wt calcium ion rather than looking at a straight 2-for-1 swap on charge balance. If we stick to mass as the reference for ppm, then the total mass has increased by 0.14%.
I do not see how you're coming up with the 1/3 and 1/2 numbers you're projecting, even "eyeballing" it. Nor do I see any point at which TDS is decreasing...
Using CaCO[sub]3[/sub] as a base, calcium's AW is approximately 40% of the molecule, meaning it's also 40% of the 88 ppm or about 36 ppm out to 80 ppm of the 200 ppm range extent.
Your 2.14:1 stated ratio appears to be a swap on mass, as you're exchanging 2x22 wt ions of sodium for each 40 wt calcium ion rather than looking at a straight 2-for-1 swap on charge balance. If we stick to mass as the reference for ppm, then the total mass has increased by 0.14%.
I do not see how you're coming up with the 1/3 and 1/2 numbers you're projecting, even "eyeballing" it. Nor do I see any point at which TDS is decreasing...
Certainly Not A Butt-Head Question!
Hi,
Now these are not butt-head questions, they are direct, to the point.:glee:
Excellent!
I will go through all of it when I have finished using the real world numbers.
It is hard for me to do the arithmetic on the forum so I will scan all of that in.
A key to remember is that we use “equivalents” to measure some things such as “hardness” this adds to the confusion, especially when the same unit or equivalent is used for two different types of measurements.
Another thing to keep in mind is that often (and in this case) the common terminology is actually descriptive. In this case, we actually do “soften” the water. Most of this terminology comes out of the world of boilers for steam engines and heating.
We “soften” the water by removing the stuff that leaves hard scaly stuff.
The total dissolved solids (TDS) that includes the hard scaly stuff but includes many things we cannot remove via ion exchange. Add to this the real world mistake many hobbyists make in their use of TDS and other conductivity meters. More later…:encouragement:
Biollante
Edit: Forgot [FONT=&]Good thought on the mass thing…[/FONT]
Edit: Added some of the formatting back in to make it readable.
Hi,
Now these are not butt-head questions,
they are direct, to the point.:glee: Excellent!
I will go through all of it when I have finished using the real world numbers.
It is hard for me to do the arithmetic on the forum so I will scan all of that in.
A key to remember is that we use “equivalents” to measure some things such as “hardness” this adds to the confusion, especially when the same unit or equivalent is used for two different types of measurements.
Another thing to keep in mind is that often (and in this case) the common terminology is actually descriptive. In this case, we actually do “soften” the water. Most of this terminology comes out of the world of boilers for steam engines and heating.
We “soften” the water by removing the stuff that leaves hard scaly stuff.
The total dissolved solids (TDS) that includes the hard scaly stuff but includes many things we cannot remove via ion exchange. Add to this the real world mistake many hobbyists make in their use of TDS and other conductivity meters. More later…:encouragement:
Biollante
Edit: Forgot [FONT=&]Good thought on the mass thing…[/FONT]
Edit: Added some of the formatting back in to make it readable.
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Let me try this...
Hi,
For the moment let me correct something my bleary, late night eyeballing messed up. Yes, I did the mass conversions in my head incorrectly… Happy days are here I blew it… Tell the world.
The approximate reduction would be about 30-ppm of TDS, including the additional a bit less than 30-ppm of sodium.
Still TDS, conductivity and osmotic pressure are reduced. The sodium levels are not drastically so drastically increased as to pose significant problems.
Of course, with or without ion exchange water softening this water is still not suitable for soft water fish.
Upon further review I believe given the information supplied, my answers were basically correct that the results upset the orthodoxy I cannot help, the fact that nowhere in the threads questions was there a single word about “real world” numbers, obviously this water is much harder than the 5-dGH I used as my example. Since no mention was made of soft water fish my comments were based on community fish and plants. No matter how offensive any of you or any magazine views the use of ion exchange water softeners for keeping fish, unless of course those ion exchange devices are sold as for aquarium use.
Ambushes are easy. No these are not "real world" calculations in that they assume perfect conversions, they are ideal, even in the places I had to approximate and yes I know this is an ambush opportunity.
I have no simple way of providing the math, I cannot get ordinary formatting to stay and since I do not believe that was the point anyway I will leave it with this.
The total amount of Ca[SUP]++[/SUP] is about 46.5-ppm with an implied approximately 13.8 Mg[SUP]++[/SUP] yielding an equivalent hardness of 173-ppm CaCO[SUB]3[/SUB].
Approximately 28-ppm Na[SUP]+[/SUP] is required to sequester the Ca[SUP]++[/SUP] and Mg[SUP]++[/SUP] by ion exchange, using sodium, yes I am aware that H[SUP]+[/SUP] or K[SUP]+[/SUP] can be used, this is obviously univalent ions replacing divalent ions, these are cation exchange resins.
In this case TDS is reduced from 200-ppm[SUP]1[/SUP] to 168-ppm. This by my calculation reduces conductivity by 62-[SUP] µS[/SUP]⁄[SUB]cm[/SUB].[SUP]2[/SUP]
Should this be used the TDS drops to about 40-ppm and conductivity falls to 62-[SUP] µS[/SUP]⁄[SUB]cm[/SUB][SUP]4[/SUP] even with all those secretly extra conductive sodium ions the orthodoxy like to worry about.
Should there be any honest interest I will capture someone with better handwriting skills than I possess and do a thread on the arithmetic and reasoning.
Biollante
[SUP]1[/SUP]208-ppm by my calculation and perhaps more telling is the 356-[SUP]µS[/SUP]⁄[SUB]cm[/SUB] and the implied 228-ppm TDS.
[SUP]2[/SUP]Based on the information provided this should be a beginning conductivity of 325-[SUP] µS[/SUP]⁄[SUB]cm[/SUB] and an ending 263-[SUP] µS[/SUP]⁄[SUB]cm[/SUB]. Using the provided data the final conductivity should be 294-[SUP] µS[/SUP]⁄[SUB]cm.[/SUB]
[SUP]3[/SUP]This as at 2C, at 25C it is 085931-bar and at 27C it is 0.093743-bar.
[SUP]4[/SUP]By my calculations at any rate it would reduce conductivity by 263-[SUP] µS[/SUP]⁄[SUB]cm[/SUB].
[SUP]5[/SUP]This as at 2C, at 25C it is 0.036175-bar and at 27C it is 0.036418-bar.
Hi,
For the moment let me correct something my bleary, late night eyeballing messed up. Yes, I did the mass conversions in my head incorrectly… Happy days are here I blew it… Tell the world.
The approximate reduction would be about 30-ppm of TDS, including the additional a bit less than 30-ppm of sodium.
Still TDS, conductivity and osmotic pressure are reduced. The sodium levels are not drastically so drastically increased as to pose significant problems.
Of course, with or without ion exchange water softening this water is still not suitable for soft water fish.
Upon further review I believe given the information supplied, my answers were basically correct that the results upset the orthodoxy I cannot help, the fact that nowhere in the threads questions was there a single word about “real world” numbers, obviously this water is much harder than the 5-dGH I used as my example. Since no mention was made of soft water fish my comments were based on community fish and plants. No matter how offensive any of you or any magazine views the use of ion exchange water softeners for keeping fish, unless of course those ion exchange devices are sold as for aquarium use.
Ambushes are easy. No these are not "real world" calculations in that they assume perfect conversions, they are ideal, even in the places I had to approximate and yes I know this is an ambush opportunity.
I have no simple way of providing the math, I cannot get ordinary formatting to stay and since I do not believe that was the point anyway I will leave it with this.
The total amount of Ca[SUP]++[/SUP] is about 46.5-ppm with an implied approximately 13.8 Mg[SUP]++[/SUP] yielding an equivalent hardness of 173-ppm CaCO[SUB]3[/SUB].
Approximately 28-ppm Na[SUP]+[/SUP] is required to sequester the Ca[SUP]++[/SUP] and Mg[SUP]++[/SUP] by ion exchange, using sodium, yes I am aware that H[SUP]+[/SUP] or K[SUP]+[/SUP] can be used, this is obviously univalent ions replacing divalent ions, these are cation exchange resins.
In this case TDS is reduced from 200-ppm[SUP]1[/SUP] to 168-ppm. This by my calculation reduces conductivity by 62-[SUP] µS[/SUP]⁄[SUB]cm[/SUB].[SUP]2[/SUP]
- Total molality goes from 4.0465-[SUP]mol[/SUP]⁄[SUB]kg[/SUB] to 3.93989-[SUP] mol[/SUP]⁄[SUB]kg[/SUB].
- Total molar mass goes from 460.02-[SUP]g[/SUP]⁄[SUB]mol [/SUB]to 335.62-[SUP] g[/SUP]⁄[SUB]mol[/SUB].
- Osmotic pressure goes from 0.085931-bar to 0.072179-bar[SUP]3[/SUP].
- The calculated ionic strength goes from 0.00537 to 0.00253.
- The activity coefficient for monovalent ions goes from 0.924 to 0.946.
- The activity coefficient for divalent ions goes from 0.730 to 0.802.
Should this be used the TDS drops to about 40-ppm and conductivity falls to 62-[SUP] µS[/SUP]⁄[SUB]cm[/SUB][SUP]4[/SUP] even with all those secretly extra conductive sodium ions the orthodoxy like to worry about.
- Total molality is 1.5720-[SUP] mol[/SUP]⁄[SUB]kg[/SUB].
- Total molar mass is 178.54-[SUP] g[/SUP]⁄[SUB]mol[/SUB].
- Osmotic pressure is 0.033383-bar[SUP]5[/SUP].
- The calculated ionic strength goes from 0.00537 to 0.00253.
- The activity coefficient for monovalent ions goes from 0.924 to 0.946.
- The activity coefficient for divalent ions goes from 0.730 to 0.802.
Should there be any honest interest I will capture someone with better handwriting skills than I possess and do a thread on the arithmetic and reasoning.
Biollante
[SUP]1[/SUP]208-ppm by my calculation and perhaps more telling is the 356-[SUP]µS[/SUP]⁄[SUB]cm[/SUB] and the implied 228-ppm TDS.
[SUP]2[/SUP]Based on the information provided this should be a beginning conductivity of 325-[SUP] µS[/SUP]⁄[SUB]cm[/SUB] and an ending 263-[SUP] µS[/SUP]⁄[SUB]cm[/SUB]. Using the provided data the final conductivity should be 294-[SUP] µS[/SUP]⁄[SUB]cm.[/SUB]
[SUP]3[/SUP]This as at 2C, at 25C it is 085931-bar and at 27C it is 0.093743-bar.
[SUP]4[/SUP]By my calculations at any rate it would reduce conductivity by 263-[SUP] µS[/SUP]⁄[SUB]cm[/SUB].
[SUP]5[/SUP]This as at 2C, at 25C it is 0.036175-bar and at 27C it is 0.036418-bar.
Internet Stuff
Hi,
For those interested here is an interesting bit on water softening.
Also the Lenntech water solutions folks have some wonderful calculators, most even give the math and sometimes an explanation.
I know I am leaving a good one out, but what little of my mind I have left isn’t cooperating.:apathy:
Biollante
Hi,
For those interested here is an interesting bit on water softening.
Also the Lenntech water solutions folks have some wonderful calculators, most even give the math and sometimes an explanation.
I know I am leaving a good one out, but what little of my mind I have left isn’t cooperating.:apathy:
Biollante
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Clear as Mud
Hi ubr0ke,
I apologize for my part in the hijack, which will continue, I think enough of my mind has returned to work the rest of the way through.
In all of this mess, I want to make sure your basic question(s) were answered.
Biollante
Hi ubr0ke,
I apologize for my part in the hijack
, which will continue, I think enough of my mind has returned to work the rest of the way through.In all of this mess, I want to make sure your basic question(s) were answered.
Biollante
If there are 1000 grams per liter, then ppm would factor by 1000 and 46.5 ppm would be about 0.0465 grams of calcium ions.Biollante;78366 said:
If we are exchanging ions at 2.14:1 on mass, then the mass should increase to 107% of its original figure, becoming 0.0498 grams of sodium ions, or 49.8 ppm in a liter.
I must be dense as all get-out because I still do not see how TDS is being lowered by the amounts you proffer or how so little sodium can sequester so much calcium...
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