# possible way to add Ca, Mg, K without adding S, Cl, CO3 etc.



## Happi (12 Jul 2021)

I have not tried this yet, but I think it is very possible. The goal is to have a Calcium and Magnesium rich water free from any Cl, S, NO3, CO3 etc. this is how it could possibly be done: We will need Calcium and Magnesium Nitrate, we can also add KNO3 in there which will add K if you want.


We will have to pass the water through something similar to Plenum or anoxic filter and have it hooked up to the container that you use to gather your RO water which can be used to change the water of your aquarium. We can do the same to the tap water as well but RO water will benefit the best from such setup. This setup will remove most of the NO3 and we can hope to achieve 0-5 ppm NO3 at the end. You can aim for whatever Ca, Mg, K levels and ignore the NO3 at this time, which will leave the system as nitrogen gas giving you very low to zero reading on NO3 levels.


*Now you can use this water for your aquarium, which is free from S, Cl, CO3 etc..*


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## X3NiTH (12 Jul 2021)

Hi there Happi

Do you have any good links for compact installations to allow this effect for small aquariums rather than the need for pond sized equipment.

With same goal of reducing pollution content of S, Cl and CO3, I have also looked at the possibility of using the Citrates of Calcium and Magnesium to remineralise RO/DI to allow for a lower conductivity level than using traditional salts. The citrates have the advantage of being easily oxidised or uptaken and thus reducing the overall conductivity of the water. It’s a future experiment so haven’t run numbers on pH effects.


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## Happi (13 Jul 2021)

Looks like we might have to use something similar to that Dr. Novak guy on YouTube, He uses canister filter such as ADA Super Jet to achieve the same. I believe we could do something similar with very low GPH pump installed to one of these (see picture) and add the needed stuff to make a plenum. Then we can let the water run into our container similar to our aquarium setup.



Take a look at this picture, this was originally my co2 reactor, we will cut the pipe to leave only few inches at the top, we don't want to pull the water at the bottom, instead we are trying to create a plenum system at the bottom which need very slow moving water (close to 0).

It's nice to try different chemicals like you have mentioned, I have not yet tried the Citrarte, i have thought about it at some point but then got busy with something else. I did try the EDTA Calcium, but it's probably not the best way to add calcium. I did try the vinegar and CaCO3 as well, but wasn't very satisfied with it. I also tried the Calcium gluconate and Calcium Chloride combination which is ok but adds lot of cl. 

In order for me to add about 10 ppm Calcium in my 50 gallon from calcium Citrate, I will need to add about 7.85 gram Calcium Citrate which will also add good amount of Carbon around 11.98 ppm.


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## akwarium (13 Jul 2021)

I use calcium acetate to reach 4.2 ppm calcium. the solubility is great but it does seriously promote bacterial growth so clouds the water in new tanks.


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## jaypeecee (13 Jul 2021)

Happi said:


> The goal is to have a Calcium and Magnesium rich water free from any Cl, S, NO3, CO3 etc.


Hi @Happi

May I ask the obvious $64,000 question? Why do you want to _eliminate_ Cl, S, NO3 and CO3 from your tank?

JPC


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## jaypeecee (13 Jul 2021)

akwarium said:


> I use calcium acetate to reach 4.2 ppm calcium. the solubility is great but it does seriously promote bacterial growth so clouds the water in new tanks.


Hi @akwarium

I guess that's entirely to be expected - feeding an organic compound to (heterotrophic) bacteria. And that's a very low calcium figure. May I ask - what is the reason for this?

JPC


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## jaypeecee (13 Jul 2021)

X3NiTH said:


> The citrates have the advantage of being easily oxidised or uptaken and thus reducing the overall conductivity of the water.


Hi @X3NiTH 

I'm very interested. What would be the reason for specifically reducing the water conductivity? Lowering GH and/or KH? Some other reason?

JPC


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## Happi (13 Jul 2021)

*@akwarium @jaypeecee

calcium acetate is ok source but you have to be careful with it, it will cause the bacteria bloom which will consume lot of O2 and this can deprive the fish from oxygen. 

We do not need much Cl, S or Na in our water for plants and fish to do well, they actually buildup and raise the TDS and continue to build up even after we change the water. Plant use these in very low amount, estimated less than 1 ppm or even less per week. So why you want to add a fertilizer that will add more and more of these three? There is no problem using CaCl, KCL, CaSo4, MgSo4, K2SO4 etc. to our water but that excess SO4 and Cl buildup will keep on going up and up. If CaNo3, MgNo3, KNO3 were used in this case, you should see the TDS will start to drop little by little day by day to certain point. Even KHCO3 will be better option if your soil is acidic and eat away the CO3. 

 Let’s use an example: Cacl vs CaNO3, add 1 ppm Ca from both and you will see that CaCl will add Ca and Cl and watch the TDS goes up and watch the Cl goes up while most of that 1 ppm Ca will be used by the plant but the Cl not so much. On the other hand, CaNo3 add 1 ppm, both Ca and NO3 will be used by plants, you will notice the TDS drop day later after these were added to the water if they were consumed by plants. We can apply the same concept to other chemicals as well. 

CO3 is also something isn’t needed by plants if you are injecting CO2 in the system, but its ok to have some in the system, again having too much CO3 isn’t a good thing either as it will hinder the plant growth and some fish, shrimp species. 

My main focus is to add the needed Nutrients without adding the above in excess and try to maintain low TDS and less water changes. Am not saying that excess SO4 will be a major concern but why add more when we can avoid it especially when its needed in very low amount. If someone still want to use these for their RO water, they should combine different source of chemicals instead of adding everything CaSO4, MgSO4, K2SO4. Instead, use CaCl, MgSo4, KHCO3, CaNO3, MgNO3, KNO3 in combination.*


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## Happi (13 Jul 2021)

jaypeecee said:


> Hi @Happi
> 
> May I ask the obvious $64,000 question? Why do you want to _eliminate_ Cl, S, NO3 and CO3 from your tank?
> 
> JPC


I wasn't sure if you were  being sarcastic because that is a quite low amount $64,000 for this question.


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## Wookii (13 Jul 2021)

Happi said:


> *@akwarium @jaypeecee
> 
> calcium acetate is ok source but you have to be careful with it, it will cause the bacteria bloom which will consume lot of O2 and this can deprive the fish from oxygen.
> 
> ...



I admire your drive to discover a way to do this and I'm interested in the results, but I'm not sure the Cl and S levels are a major issue?

I remineralise RO with MgSO4, CaCl2 (3:1 ratio) and K2CO3, targeting GH5-6 and KH1-2. That results in Cl levels of around 45-50ppm, and SO4 levels of around 75-80ppm (per @Zeus.'s excellent calculator). These levels should not build up over time as you are only ever adding them to remineralise the RO water that is being equally exchanged for water already in the tank. Further I only have them at that level and target GH for the benefit of the inverts I keep. If you don't keep shrimp and/or snails, then GH could be half that, and the resulting Cl and SO4 levels would be half that also.


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## Happi (13 Jul 2021)

@Wookii 

am not concerned about the Cl or SO4 levels as much to certain levels. the goal of this thread is to find a way to reduce these but not entirely get rid of them as they are beneficial to the aquarium. 

regarding the water changes, sure it will bring down those number but people use other chemicals that are added to the water afterward that are rich in SO4, Cl etc. which will result in the above that I have mentioned.


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## Wookii (13 Jul 2021)

Happi said:


> regarding the water changes, sure it will bring down those number but people use other chemicals that are added to the water afterward that are rich in SO4, Cl etc. which will result in the above that I have mentioned.



I'm not sure how commonly Cl or SO4 will be added elsewhere? 

Most people will use KNO3 for Nitrate addition, and KH2PO4 for Phosphate addition. Some may add a bit of K2SO4 for additional Potassium, but for most people remineralising RO (our assumption here) and adding carbonates to have at least some KH, will use either K2CO3 or KHCO3 which will eliminate the need for any K2SO4.


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## Happi (13 Jul 2021)

Wookii said:


> I'm not sure how commonly Cl or SO4 will be added elsewhere?
> 
> Most people will use KNO3 for Nitrate addition, and KH2PO4 for Phosphate addition. Some may add a bit of K2SO4 for additional Potassium, but for most people remineralising RO (our assumption here) and adding carbonates to have at least some KH, will use either K2CO3 or KHCO3 which will eliminate the need for any K2SO4.


not so common but some people have a tendency to raise these levels through these chemicals. again, the main purpose of this thread is to reduce these levels while maintaining a good amount of Ca, Mg, K and such.

people here in Utah have a very hard water which is rich in Cl and SO4, they still add K2SO4 to raise the K. some of them cannot use KNO3 because they are maxing out their NO3 test kits. they don't have much choice but to add KCL or K2SO4, KHCO3 is not a option  due to hard water. KNO3 is good option but again they are already maxing their NO3 levels on their test kits. so if we could remove the NO3 from KNO3 and only extract K from it, this would be a better option. there are other option too CaNO3 + K2SO4 mixed in the solution to _Precipitate_ the SO4 into CaSO4, leaving you with much higher K in the solution, with some NO3. but this is not the best way to do things.

*wouldn't it be nice to have a Calcium at 30 ppm with 1 ppm Cl, S or Co3?*


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## jaypeecee (13 Jul 2021)

Happi said:


> CO3 is also something isn’t needed by plants if you are injecting CO2 in the system, but its ok to have some in the system, again having too much CO3 isn’t a good thing either as it will hinder the plant growth and some fish, shrimp species.


Hi @Happi 

The carbonate (CO3--) proportion of dissolved inorganic carbon (DIC) will be dependent upon the pH of the water column. I'm not sure why CO3-- would hinder the growth of fish and shrimp. The GH cations such as Ca++ and Mg++ are certainly important to fish for osmoregulation.


Happi said:


> ...some of them cannot use KNO3 because they are maxing out their NO3 test kits.


The above is not a problem. It can easily be addressed by using dilution of the aquarium sample with distilled water.



Happi said:


> ...wouldn't it be nice to have a Calcium at 30 ppm with 1 ppm Cl, S or Co3?


Which such low anion concentrations, how would you stabilize pH?



Happi said:


> I wasn't sure if you were being sarcastic because that is a quite low amount $64,000 for this question.


Me, sarcastic? Never! 

JPC


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## X3NiTH (13 Jul 2021)

The presence of increased amounts of Sulphate and Chloride in water systems are the hallmarks of soil disturbance and as these amounts increase there is a corresponding loss in biodiversity in the micro fauna downstream from the disturbance. My interest in this is the replication of the waters that flow through the environment of ‘Forrest over Limestone’ on the island of Borneo, the conductivity of the water is very low even though the water flow is through Karst, a lot of the extra mineral nutrition entering the water column will come from the breakdown products of biological processes happening on the mountain. The conductivity of this water is very low down around 40 micro Siemens, so replicating the hardness degree and pH of this water is quite difficult if using Chlorides and Sulphates of Calcium and Magnesium.

The water in question that I’m referencing is Site 1 in this document on the effects of sediment pollution on food webs on the Kelian River in Borneo -



			https://digital.csic.es/bitstream/10261/59956/1/marine.pdf
		


For me the concern is more for the epiphyte community plants mainly the obligate rheophytes (Bucephalandra) that have to put up with malnourished sources of mineral fertilisation but are still able to thrive.

Speaking aside from this in relation to an aquarium setting it may be beneficial to have nutritious water that can support plants but have low conductance in the water to allow more micro fauna to exist and freely breed without hindrance by excess pollution that may reduce numbers, for instance Daphnia which can be used as a metric to ascertain the pollution status of a standing water source such as rainwater which is mainly devoid of mineralisation and thus very pure and of naturally low conductance.

There is a possible advantage to supplementing with the use of Citrates and Acetates of Calcium and Magnesium in that they both provide molecular carbon that can be utilised by biological processes either by plant or animal to utilise how they see fit, either for incorporating into tissue or using it for respiration activity.

If low conductivity is the aim with a good nutritional balance then you need to get creative with blending compounds. Generally on the whole this isn’t necessary as what comes out the tap ‘should do’ but it doesn’t always work for everything.

With respect to using the Carbonates of Magnesium and Calcium it is quite easy to get a moderate degree of hardness (around 7dKH and 7dGH is what I aimed for) by adding the correct amounts within solubility rules to 1L of Refrigerated Cold Pressurised Carbonated RO/DI thus forming partial Bicarbonate solution over a few hours and when this milky solution (with undissolved sediment) is added to 26L (Jerry can is 27L brimmed) of RO/DI the water after an hour or so will be crystal clear and the water co2 content will be around 30ppm which means you can perform a water change at the top of a co2 profile.


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## akwarium (15 Jul 2021)

jaypeecee said:


> Hi @akwarium
> 
> I guess that's entirely to be expected - feeding an organic compound to (heterotrophic) bacteria. And that's a very low calcium figure. May I ask - what is the reason for this?
> 
> JPC


I only use it to add minerals back to the DI-water I use for water changes.  my fish prefer soft water, and I don't see much need for higher calcium figures. My problem with calcium sulfate was that it takes quite long to dissolve. 



Happi said:


> *@akwarium @jaypeecee
> 
> calcium acetate is ok source but you have to be careful with it, it will cause the bacteria bloom which will consume lot of O2 and this can deprive the fish from oxygen.
> 
> ...



Once the filter is established the water remains crystal clear after adding acetate(with a water change), but I have a large filter for my tank size.  with low turnover, smaller filter surface area or higher dosing it might continue to cloud the water......  Acetate should be quite a good carbon source for bacteria, not only for oxidation but also to be incorporated in cells.  Low carbon hardness (HCO3) might mean that an alternative carbon source could be beneficial to some extent.   Plants don't need it, but nitrobacter do need some source of carbon and usually it is HCO3. 

I use KHCO3, MgSO4 and Calcium-acetate for hardness. and MgNO3, K2SO4 ,KH2PO4 and micromix for fertilizer.


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