# Help with EI Calcs please.



## Christian Walker (26 Feb 2015)

OK Ive read the EI article and would be grateful if someone can have a quick look to make sure I'm understanding the maths correctly.

My water is neutral pH and medium hardness.

I have these salts....
MgSO4 (magnesium sulphate), 
K2CO3, (Potassium Carbonate),
KH2PO4, (Monopotassium phosphate), 
KNO3, (Potassium nitrate).
TNC Trace

My tank, for estimative purposes is 40 UK gallons and my lighting is 78W of T5 so Im calling that 2wpg. (Is this low medium or high lighting btw) ?


The article says...

Sunday – 50% or more Water Change then dose [3/16 teaspoon KNO3] + [1/16 teaspoon KH2PO4] + [½ teaspoon MgSO4]
Monday – 1/16 teaspoon CSM+B
Tuesday - [3/16 teaspoon KNO3] + [1/16 teaspoon KH2PO4] + [½ teaspoon MgSO4]
Wednesday - 1/16 teaspoon CSM+B
Thursday - [3/16 teaspoon KNO3] + [1/16 teaspoon KH2PO4] + [½ teaspoon MgSO4]
Friday – Rest
Saturday - Rest

From the above values based on a 20gal tank Im doubling as mine is 40gal appr.  Giving

Sun 3/8 tsp KNO3 + 3/16 tsp KH2PO4 + 1tsp MGSO4
Mon 1/8 tsp Trace
Tue  3/8 tsp KNO3 + 3/16 tsp KH2PO4 + 1tsp MGSO4
Wed 1/8 tsp Trace
Thy 3/8 tsp KNO3 + 3/16 tsp KH2PO4 + 1tsp MGSO4
Fr/Sa REST

weeky totals therefore

KNO3     = 1+1/8th tsp,  KH2PO4 = 9/16th tsp,  MGSO4  = 3 tsp,  TRACE   = 1/4 tsp

Multiply x 4 for a 1 mths supply to be mixed in 600ml water  

KNO3     = 1+1/8th tsp  x 4 = 4 1/2 tsp
KH2PO4 = 9/16th tsp x 4 = 3 1/4 tsp
MGSO4  = 3 tsp x 4 = 12 tsp
TRACE   = 1/4 tsp x 4 = 1tsp


OK So

1) Are my calculations correct ?
2) Where does the K2CO3 come into things or do I not need it ?  
3) Do I need to adjust this based on my lighting levels of 2wpg ?
4) Am I right that the CSM+B in the article is the same as TNC trace ?


Sorry for such a long post....


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## ian_m (26 Feb 2015)

Dose as per here. No need to calculate too much, assume 200litres so 40ml per dose....done.
http://www.aquariumplantfood.co.uk/fertilisers/dry-chemicals/starter-kits/ei-starter-kit.html

Or if you must dose dry salts...use this, can work in tsp which is nice. Or just use 5-6gr = 1 tsp.
http://calc.petalphile.com/

K2CO3 is used to make the water harder (more buffer) for those using RO or very soft tap water.

Yes is high light so behave accordingly...


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## Christian Walker (26 Feb 2015)

Thanks Ian m  I won't be putting dry salts into the tank... too much faff.  But good to know what asp weighs so i can put the right amount into the water.

So I can use my K2CO3 to remineralise my shrimp tank when i get it, or do i need something a bit more balanced for that ?


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## ian_m (26 Feb 2015)

Bit more balanced maybe.
http://www.theplantedtank.co.uk/RO.htm

I assume you are using RO ?


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## Another Phil (26 Feb 2015)

Hi Christian,


Christian Walker said:


> for estimative purposes is 40 UK gallons and my lighting is 78W of T5 so Im calling that 2wpg


Someone will correct me if I'm wrong but I believe the watts/gall are USA gallons, not imperial, so your 40imp gall is 48 USA gall, so 1.6W/gall.

useful table here;
http://i.imgur.com/RbWzU.jpg
cheers phil


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## Christian Walker (26 Feb 2015)

Ian m.  No Im not using RO.  

I just followed the mixing instructions in that link you gave me with the 500ml of water, mixed it well until dissolved, and added the 40ml to the tank.  My rainbow fish became immediately stressed  so I have just had to do a large water change.  

Phil, from that chart, I have LOW light ?? My tank hight is 20" with lights 3" above.


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## ian_m (26 Feb 2015)

Christian Walker said:


> My rainbow fish became immediately stressed


Something must be wrong somewhere. I once dosed 1litre of EI solution, due to pump failure,  into 180litre tank, giving nitrate at 250ppm and PO4 at 80ppm and no change in fish behaviour for days until I noticed container was empty. Most annoyingly, other than cost, is made b**ger all difference to the plants....

I bet you tap water may be higher nitrate and phosphate that EI is giving so can't be them. MgSO4 is harmless and Mg may present in tap water anyway.

Try adding the EI solution when the fish are not looking ? Down the side of the tank ? Some people who worry, fill a large jug with tank water, add EI and poor back.


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## naughtymoose (26 Feb 2015)

Where is that table from Phil? No metion of wattage?


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## ian_m (27 Feb 2015)

Wattage is irrelevant just as tank width is not mentioned in the table. Wattage is roughly constant per unit tank width.


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## Another Phil (27 Feb 2015)

Hi naughtymoose,


naughtymoose said:


> Where is that table from Phil? No metion of wattage?


Sorry, I copied a link which changed to an embedded image - I'd find that impossible if it was intentional 
there is a version here;
http://www.plantedtank.net/forums/showthread.php?t=105774

(the first link that Hoppy provides has a huge amount of info as well.)
initially I copied it from imagur? maybe.

cheers phil


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## naughtymoose (27 Feb 2015)

Thanks Phil. I get it now!


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## Christian Walker (2 Mar 2015)

The proportions on that link to aquarium plant food is very different to the mix suggested in the EI article.  So I am now completely confused and considering selling these salts.  Whats the point of a method if all the calculations are way different ?  Can anyone enlighten me ?  
Were my original calculations correct based on the original article someone ?


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## Henry (2 Mar 2015)

Christian Walker said:


> The proportions on that link to aquarium plant food is very different to the mix suggested in the EI article.  So I am now completely confused and considering selling these salts.  Whats the point of a method if all the calculations are way different ?  Can anyone enlighten me ?
> Were my original calculations correct based on the original article someone ?



EI isn't an exact science, hence "estimative". Go with your original calculations and observe your plants.


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## Christian Walker (2 Mar 2015)

Henry said:


> EI isn't an exact science, hence "estimative". Go with your original calculations and observe your plants.




Thanks Henry, yeah I completely understand the concept of estimation.  It just seemed that when one calculation was so completely different to the other, that estimation became a nonsense.  How I see "estimation" to apply is "about 4, meaning hey if its 3.8, 3.9, 4 is good enough"  but in this case, the figure for one of the salts for example, was double what the other calculation suggested.  Thats not estimation IMO.

I have mixed it according to the link.  Will see what happens.  I introduced it slowly today and the fish were not bothered, which is a good thing at least.


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## ian_m (2 Mar 2015)

You must have made an error somewhere. Using http://calc.petalphile.com/ for instance.

Using aquariumplantfood dosing, in 180litre tank, 4tsp of KNO3 into 500ml water, dosing 40ml gives a tank ppm of 5.7ppm.

Dosing your 3/16tsp -> 1.8gr KNO3 gives 6.1ppm.

Good enough for IE.


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## Christian Walker (2 Mar 2015)

ian_m said:


> You must have made an error somewhere. Using http://calc.petalphile.com/ for instance.
> Using aquariumplantfood dosing, in 180litre tank, 4tsp of KNO3 into 500ml water, dosing 40ml gives a tank ppm of 5.7ppm.
> Dosing your 3/16tsp -> 1.8gr KNO3 gives 6.1ppm.
> Good enough for IE.



Looking back at my maths I don't believe I have made a mathematical error Ian M.  Take a look.  

The MGSO4 = 3 tsp x 4 = 12 tsp for my tank based on the EI article.  
Compared to 6tsp based on the APF calculation.
Thats not estimation is it.  Its way out.

I have calculated the MgSO4 as follows

EI article says 1/2 tsp 3 days a week for a 20gal tank.  
Thats 1 1/2tsp a week or 6tsp every 4 weeks.  
My tank is 40gal so double that = 12 tsp.

The same applies for the KH2PO4.... the amount is much lower in the APF calculation in that as well.  

I am more inclined to trust the article as I know who wrote it, and whilst his word is not God, its close enough for me.  I just wanna get confirmation that my maths is correct as shown in my OP.


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## ian_m (2 Mar 2015)

Same with MgSO4, approximate the same ppm in the tank.




 



 
Just checking as well...as I may be wrong....


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## Christian Walker (2 Mar 2015)

Have no idea what all that means.  LOL


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## ian_m (2 Mar 2015)

Its the ppm calculations for dosing by dry salts or liquid. Both produce the same ppm in the tank.


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## Rahms (2 Mar 2015)

the EI thread gives it in terms of 20 gal, just double it and be done!  I'm fairly certain its what most people on the forums will be using, so there's no need to doubt it.

edit: that said, it looks like you've doubled 1/16 to get 3/16?  (KH2PO4)


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## dw1305 (2 Mar 2015)

Hi all,





Christian Walker said:


> The MGSO4 = 3 tsp x 4 = 12 tsp for my tank based on the EI article. Compared to 6tsp based on the APF calculation.


 It may be because one calculation is using MgSO4 ("anhydrous"), and the other is using MgSO4.7H2O ("heptahydrate"). 

Whatever it says on the container it will be the "heptahydrate" form when you use it, because it will pick up atmospheric water. It makes quite a big difference to the % of magnesium in the salt.

cheers Darrel


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## Chris Jackson (2 Mar 2015)

I find this calculator very straightforward with no faff or maths ....https://www.thenutrientcompany.com/aquarium/calculators/ei_calculator/


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## Christian Walker (3 Mar 2015)

Rahms said:


> the EI thread gives it in terms of 20 gal, just double it and be done!  I'm fairly certain its what most people on the forums will be using, so there's no need to doubt it.
> 
> edit: that said, it looks like you've doubled 1/16 to get 3/16?  (KH2PO4)



Thanks Rahms, you are quite right, I have done a slight transposition on the Potassium Phosphate. Thanks... see thats what I was after... someone to check my maths.  Im more than happy to trust Clive's EI article.  Its my maths thats dodgy ! lol


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## Christian Walker (3 Mar 2015)

dw1305 said:


> Hi all, It may be because one calculation is using MgSO4 ("anhydrous"), and the other is using MgSO4.7H2O ("heptahydrate").
> 
> Whatever it says on the container it will be the "heptahydrate" form when you use it, because it will pick up atmospheric water. It makes quite a big difference to the % of magnesium in the salt.
> 
> cheers Darrel




OK, I will take your word on that Darrel, the salts I have are from Fluid Sensor.  Its labelled as MgSO4.  What is the difference between anhydrous and heptahydrate please ?  I presume that Clive's EI article would take that into account and refers to the latter ?


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## dw1305 (3 Mar 2015)

Hi all, 





Christian Walker said:


> What is the difference between anhydrous and heptahydrate please ?


It is the "water of crystallization", if a salt doesn't contain any water it is "anhydrous". In the case of magnesium sulphate anhydrous it is "hygroscopic", with the stable form of the salt absorbing "7H2O" to become "Epsom Salts". If you heat "Epsom Salts" you can drive off the water to give MgSO4 anhydrous but, unless you keep it in a desiccator, it will pick up atmospheric water until it becomes fully hydrated again.

When you work out the percentage magnesium (Mg) you need to know the relative molecular mass (RMM) of the salt, by adding together the relative atomic mass (RAM) of the elements.

RAM
Mg = 24
S = 32
O = 16
H = 1

MgSO4 (anhydrous) = 24+32+(4*16) RMM = 120 and the  %Mg = 24/120, so it contains ~ 20% Mg.

Add in the "water of crystallization" and you add 14 hydrogen (H) atoms  and 7 (O) oxygen atoms :
24+32+(4*16) + (14*1)+(7*16) ~ 24+32+64 = 120 + 14+112= 126 ~ 120 + 126 = 246 (this is the RMM "Relative Molecular Mass" of MgSO4.7H2O)

So "Epsom Salts" have 24/246 ~ 10% Mg.

cheers Darrel


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## ltsai (3 Mar 2015)

Don't forget mg is a micro. May not be needed unless you are using RO water.


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## Christian Walker (3 Mar 2015)

Hi Darrel, thanks for that explanation... I managed to follow that.  

It still does not explain why the proportions of MgSO4 by the aquarium online formula suggested by Ian M, in whatever state, is only half that of the figure in ceg's EI article.  Unless ceg is assuming the use of anhydrous, and aquarium online are assuming the use of heptahydrate.

Im going to follow the aquarium online formula I think, especially since I am not using RO water.  But it would be useful for clarification within the article. (It could be there but I missed it I suppose, but I don't recall anything that specific). 

Either way, this stuff is interesting for sure.


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## dw1305 (3 Mar 2015)

Hi all,





Christian Walker said:


> It still does not explain why the proportions of MgSO4 by the aquarium online formula suggested by Ian M, in whatever state, is only half that of the figure in ceg's EI article. Unless ceg is assuming the use of anhydrous, and aquarium online are assuming the use of heptahydrate.


Could be, but I don't think it really matters, it is like "Itsai" posts,  if you have some, you probably have enough. Again if you have "too much" it really doesn't matter, it isn't toxic, it doesn't cost much and if you are adding EI you aren't too concerned by raised hardness or conductivity. 





ltsai said:


> Don't forget Mg is a micro. May not be needed unless you are using RO water.


 True it is a micro-element, but most UK water supplies don't actually contain much Mg, this is just to do with geology.

The situation is different in the USA where a lot of the limestone aquifers have undergone <"dolomitisation">, where some proportion of the calcium in CaCO3 has been replaced by magnesium, and they often assume that the plants Mg requirement will be supplied by the water supply.

cheers Darrel


.


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## Christian Walker (3 Mar 2015)

Darrel your comment about not being worried about raised hardness is interesting.  How might one keep a planted aquarium in such a way that hardness does not get significantly increased ?  I would like to keep some Apistogrammas and they tend to be happier in water that is not too hard.


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## Zak Rafik (14 Apr 2015)

Chris Jackson said:


> I find this calculator very straightforward with no faff or maths ....https://www.thenutrientcompany.com/aquarium/calculators/ei_calculator/


Hi Chris, 
I find the website awesome too. 
But there is one thing which I don't understand. In the website, it mentions 2 rest days.


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## Chris Jackson (14 Apr 2015)

Good Morning Zak,

Why are 2 rest days a problem?


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## Zak Rafik (14 Apr 2015)

Hi
Good afternoon from Singapore.
Doesn't that mean one less dose of trace?
aquariumplantfood.co.uk says to dose 3 times per week for both Macro & Micro and 1 rest day.
I checked out both aquariumplantfood.co.uk and TNC's trace salts and the mixture is the same.
Maybe the difference is in the amount per dose. Maybe?
Cheers.

BTW If I can 2 rest days, all the more better.


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## Chris Jackson (14 Apr 2015)

Good afternoon! Right I see, I wouldn't worry too much just follow whatever suits you. It's all a guessimate after all...


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## dw1305 (14 Apr 2015)

Hi all,





Christian Walker said:


> How might one keep a planted aquarium in such a way that hardness does not get significantly increased ? I would like to keep some Apistogrammas and they tend to be happier in water that is not too hard.


 I keep planted tanks with _Apistogramma._ I haven't tried any of the real black water species, but I've had plenty of fry from _Apistogramma cacatuoides _and _A. agassizii_. I only have "easy" plants, and all my tanks are jungles. 

I have hard tap water, so I use rain-water for the tanks. All the tanks are low tech. and I feed the plants via the "Duckweed Index". There is more <"in your thread from 2013">. 

cheers Darrel


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## Christian Walker (14 Apr 2015)

Thanks Darrel... how do you ensure the rainwater is clear of any nasties ?  Im not sure I trust my roof to be clean.  Any pics of one of your apisto tanks please ?


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## dw1305 (15 Apr 2015)

Hi all, 





Christian Walker said:


> how do you ensure the rainwater is clear of any nasties ?


 I've used rain-water without any problems since the 1970's, but I've also got a KISS method of testing the rain-water for agricultural pollutants etc, it is the <"Daphnia bioassay"> it just means you have _Daphnia_ in the water butt, and as long as there are swimming _Daphnia_ in the water you draw off its OK to use.

I've got some _agassizii_ at the moment, this is a spare sub adult male. I don't see my breeding male very often, but he is a stunner.



 

I've got some _Apistogramma_ pictures in these threads: <"_Apistogramma cacatuoides_">. 

The "best" dwarf cichlids I've kept were _Dicrossus maculatus, _but that ended <"_in tears_">.

cheers Darrel


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