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Help with EI Calcs please.

Christian Walker

Christian Walker

Member
Joined
17 Jul 2013
Messages
125
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....
 
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 ?
 
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.
 
Christian Walker said:
My rainbow fish became immediately stressed
Click to expand...
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.
 
Wattage is irrelevant just as tank width is not mentioned in the table. Wattage is roughly constant per unit tank width.
 
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 ?
 
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 ?
Click to expand...

EI isn't an exact science, hence "estimative". Go with your original calculations and observe your plants.
 
Henry said:
EI isn't an exact science, hence "estimative". Go with your original calculations and observe your plants.
Click to expand...


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.
 
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.
 
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.
Click to expand...

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

DryDose_zpsnaye6blh.png


LiquidDose_zps8vdoldnv.png

Just checking as well...as I may be wrong....
 
Its the ppm calculations for dosing by dry salts or liquid. Both produce the same ppm in the tank.
 
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? :p (KH2PO4)
 
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