# Replace KH2PO4 ?



## eminor (9 Aug 2021)

Hello, I use the tnc complete fertilizer, I would like to switch to the EI method, in the drugstore near me, it is not easy to get all the mineral salts, is it possible to prepare the fertilizer with the ingredients from the list below?

Is it possible to replace KH2PO4?
Is CSM + B mandatory? thx

List: 
KCl
KNO3
Na3PO4 . 12H2O
K2SO4
MgSO4.7H2O


----------



## Zeus. (9 Aug 2021)

Technically yes, as it contains PO4, however I would not use it without going by our Expert @dw1305 and/or our Chemist @X3NiTH. (they should answer soon )
I sure there is a good reasons why we don't use it apart from the Na and it having no K.

As to CSM+B any good trace mix should do as CSM+B is so expensive, post what you can get your hands on and will take a look


----------



## eminor (9 Aug 2021)

Zeus. said:


> Technically yes, as it contains PO4, however I would not use it without going by our Expert @dw1305 and/or our Chemist @X3NiTH. (they should answer soon )
> I sure there is a good reasons why we don't use it apart from the Na and it having no K.
> 
> As to CSM+B any good trace mix should do as CSM+B is so expensive, post what you can get your hands on and will take a look


Thank you, at my drugstore, I can have almost everything that makes up the csm + b except perhaps the molybdenum, I imagine that it must be complicated to make yourself? also, for the iron there are several types, can't find any mix


----------



## dw1305 (9 Aug 2021)

Hi all,


eminor said:


> Is it possible to replace KH2PO4?


You could use dipotassium phosphate (K2PO4). Phosphate compounds are <"largely insoluble">, so you only really have the group one metals (and ammonium (NH4+)) as cations. <"Phosphate buffers"> might be an option ?


Zeus. said:


> I sure there is a good reasons why we don't use it apart from the Na and it having no K.


Yes, it is pretty unsuitable.

You have sodium (Na) as the cation, rather than potassium (K). You also have the issue of not actually containing much PO4---, you've got 3 x Na (RAM = 23 =  69) and 12 H2O (12 * 18 = 216).

Because it is a compound that has three sodium atoms it is also highly basic, so much so that it is used to <"saponify fats"> in soap making.

cheers Darrel


----------



## eminor (10 Aug 2021)

Thank you, finally I found the KH2PO4, this is what I can get, is there any extra stuff, or is there any missing? thx

*K2CO3 
MgSO4 7H2O 
K2SO4 
KNO3 
KH2PO4 
Trace Mix :  Fe 7,48% ; Mn 1.82% ; Zn 1.16% ; B 1.05% ; Cu 0.23% ; Mo 0.15%*


----------



## plantnoobdude (10 Aug 2021)

eminor said:


> Thank you, finally I found the KH2PO4, this is what I can get, is there any extra stuff, or is there any missing? thx
> 
> *K2CO3
> MgSO4 7H2O
> ...


pottasium nitrate, monopottasium phosphate and the micro mix and you should be good to go.


----------



## Zeus. (10 Aug 2021)

eminor said:


> Trace Mix : Fe 7,48% ; Mn 1.82% ; Zn 1.16% ; B 1.05% ; Cu 0.23% ; Mo 0.15%


Which is virtually the same as APFUK trace mix which many folk use with success


----------



## eminor (10 Aug 2021)

plantnoobdude said:


> pottasium nitrate, monopottasium phosphate and the micro mix and you should be good to go.


What about Magnesium or calcium, not needed ? thx


----------



## dw1305 (10 Aug 2021)

Hi all,


eminor said:


> K2CO3





eminor said:


> What about Magnesium or calcium, not needed ?


Do you have <"very soft water?"> If you do? you may need a calcium (Ca) salt (usually CaCl2.6H2O). If you don't have very soft water, you don't need the potassium carbonate (K2CO3). You will need to add some magnesium (Mg), most water in W. Europe doesn't contain much for <"geological reasons">.

cheers Darrel


----------



## eminor (10 Aug 2021)

dw1305 said:


> Hi all,
> 
> 
> Do you have <"very soft water?"> If you do? you may need a calcium (Ca) salt (usually CaCl2.6H2O). If you don't have very soft water, you don't need the potassium carbonate (K2CO3). You will need to add some magnesium (Mg), most water in W. Europe doesn't contain much for <"geological reasons">.
> ...



Hard water, there is the report :

Magnesium 3.8 MG/L
Calcium 120 MG/L

so i need *MgSO4 7H2O too ? thx*


----------



## plantnoobdude (10 Aug 2021)

eminor said:


> Hard water, there is the report :
> 
> Magnesium 3.8 MG/L
> Calcium 120 MG/L
> ...


i'd just add some Magnesium perhaps 10-20 ppm you have more than enough calcium. you can add in daily fert dose or at water change once per week, or both.


----------



## eminor (10 Aug 2021)

plantnoobdude said:


> i'd just add some Magnesium perhaps 10-20 ppm you have more than enough calcium. you can add in daily fert dose or at water change once per week, or both.


thank you, is there any guide for EI mix ?


----------



## John q (10 Aug 2021)

Not sure if this answers your question eminor but you could either download this ~








						IFC Aquarium Fertilizer Calculator
					

Hello everyone,  Based on its ancestor, the new IFC Aquarium Fertilizer Calculator is completed at last. This has been a long (sometimes fun, sometimes painful) adventure for me. I have spend more time than I care to admit but here it is, ready to roll. Home screenshot here below:  Background...



					www.ukaps.org
				





Or use this ~





						Rotala Butterfly | Planted Aquarium Nutrient Dosing Calculator
					

Planted Aquarium Nutrient Dosing Calculator



					rotalabutterfly.com
				




Edit: my bad ~ EI DOSING USING DRY SALTS


----------



## plantnoobdude (10 Aug 2021)

eminor said:


> thank you, is there any guide for EI mix ?


there is a good one on barrreport The Estimative Index of Dosing, or No Need for Test Kits
and ukaps. 
generally its 
20-30ppm NO3
20-30ppm K
2-3ppm Po4
and 0.3-1.2 Fe if i remember correctly


----------



## MichaelJ (10 Aug 2021)

dw1305 said:


> Hi all,
> 
> 
> Do you have <"very soft water?"> If you do? you may need a calcium (Ca) salt (usually CaCl2.6H2O).


Hi @dw1305 / @Zeus.  For the Ca part of GH, what do you think about using Calcium Sulfate (CaSo4 or Gypsum) instead of Calcium Chloride (CaCl2) ?   I am asking because I saw a mention somewhere that Chloride may not be good for the plants at elevated levels (whatever that level is...). I have been using CaCl2 / MgSo4 for 3 months now to target ~5.5-6.5 GH and haven't noticed any issues, so I am just wondering if there are any benefits or drawbacks either way?  FWIW with CaSo4 for the same amount of Ca ppm I would add  ~23 ppm of Sulfate vs. ~40 ppm of Cl with CaCl2 (I don't add any other Cl except for what I get from my KCl softened tap water...).   

Cheers,
Michael


----------



## dw1305 (10 Aug 2021)

Hi all,
@eminor, You don't need an additional calcium or carbonate source, you have plenty of both in the tap water. You still need magnesium, 10 ppm is plenty.

Cheers Darrel


----------



## dw1305 (10 Aug 2021)

Hi all, 
Calcium sulphate is fine, but has very limited solubility.

Cheers Darrel


----------



## Zeus. (10 Aug 2021)

dw1305 said:


> but has very limited solubility.






Which is why some folk who use 100% RO go for Calcium Nitrate to get there Ca

(The about table is a pre-release remineraliser for the IFC Calculator - the reason for CaSO4 only showing 1% solubility is it is dry dosed direct to tank )


----------



## MichaelJ (10 Aug 2021)

Zeus. said:


> View attachment 173000
> 
> Which is why some folk who use 100% RO go for Calcium Nitrate to get there Ca
> 
> (The about table is a pre-release remineraliser for the IFC Calculator - the reason for CaSO4 only showing 1% solubility is it is dry dosed direct to tank )


Hi @Zeus. Thanks for the chart. As a non-chemist I am trying to understand the implications of the solubility level as it relates to our dosing, plants etc. Does it mean it's not as efficient for the plants/livestock and we have to use more to get the same effects vs a different compound ? or is it that it just takes a longer time to dissolve in the water column and eventually becomes just as efficient as a compound with a higher solubility level?
Cheers,
Michael


----------



## Zeus. (10 Aug 2021)

If your making a dosing solution, you really want salts that are highly soluble, so you can make a concentrated solution of 500ml to a couple of litres and dose 10 to 100ML a dose and reach your target ppm easy



Most are fine if you can get 100g to dissolve in a litre, if it does not all dissolve it will remain a solid at the bottom of your dosing bottle and you will not reach your target ppms.

So for salts like CaSO4, CaCO3 and MgCO3 it is best to dose direct into tank if you use them, then al least if all the ions get used more just dissolve into water- however this can be an issue if your after reaching a specific hardness for RO water for specific shrimp/fish then you must be sure of your correct salts to achieve the hardness


----------



## MichaelJ (10 Aug 2021)

Zeus. said:


> Most are fine if you can get 100g to dissolve in a litre, if it does not all dissolve it will remain a solid at the bottom of your dosing bottle and you will not reach your target ppms.
> 
> So for salts like CaSO4, CaCO3 and MgCO3 it is best to dose direct into tank if you use them, then al least if all the ions get used more just dissolve into water- however this can be an issue if your after reaching a specific hardness for RO water for specific shrimp/fish then you must be sure of your correct salts to achieve the hardness


@Zeus. Thanks for the explanation!


----------



## MichaelJ (15 Aug 2021)

Zeus. said:


> If your making a dosing solution, you really want salts that are highly soluble, so you can make a concentrated solution of 500ml to a couple of litres and dose 10 to 100ML a dose and reach your target ppm easy
> View attachment 173002
> Most are fine if you can get 100g to dissolve in a litre, if it does not all dissolve it will remain a solid at the bottom of your dosing bottle and you will not reach your target ppms.
> 
> So for salts like CaSO4, CaCO3 and MgCO3 it is best to dose direct into tank if you use them, then al least if all the ions get used more just dissolve into water- however this can be an issue if your after reaching a specific hardness for RO water for specific shrimp/fish then you must be sure of your correct salts to achieve the hardness


@Zeus, I was doing WC earlier this morning and used CaSO4 for the first time. 2 grams dissolved fine in my 5 gallon bucket - as it should given the 2.4 gr/L solubility limit... I remember back in the day when I used Equilibrium (before I switched to CaCl2 and now CaSO4) there were always a lot undissolved residue at the bottom of my 5 gl buckets, so that must have quite a low saturation point (I used to use about 8 gr of Equilibrium per bucket back then). Of course, when I would dump the residue in the tanks it would dissolve just fine.
Cheers,
Michael


----------



## eminor (2 Sep 2021)

Hello, I use daily 3.75 ml of tnc complete, I have a little bit of BBA, the cause seemed to be the co2 and the pump too weak, I modified all that. all the plants regain vigor, it's a good sign but this algae is tough, I have mineral salts, but I don't know how to copy the formula of tnc complete, any idea? thanks

here is what I have:

KH2PO4
KNO3
K₂SO₄
MgSO₄

Trace: Fe 7.48%; Mn 1.82%; Zn 1.16%; B 1.05%; Cu 0.23%; Mo 0.15%

I'm afraid of ei dosing because i'm afraid that going from tnc to ei will make bba worse 

also, what if i miss a water change in EI ?


----------



## bazz (2 Sep 2021)

Hi,
As previously suggested, this is the best tool out there IFC Aquarium Fertilizer Calculator for anything fert related, I.E. cloning commercial brands and concocting your own regime.
Cheers!


----------

