# N-P-K Measurements ?



## lil-lynx (30 May 2011)

Hello i have bads of Nitrogen , Phosphates and Potassium (NPK) I was wondering if anyone could tell me the amounts needed to dose a 5 x 1.5 x 2  (feet) tank


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## CeeJay (31 May 2011)

Hi Chris

A quick calculation tells me your tank holds 112 US gallons.
The amounts below are for a 120 gallon tank so this would be good enough.
13.5 tsp KNO3
4.5 tsp KH2PO4
36 tsp MgSO4
Mix it all up in 600ml water and dose 50ml 3 times a week.

You will also need to get yourself some Trace elements (our sponsors are a good place to start   )
You'll need 3 tsp in 400ml water and dose 50ml twice a week.

Do not mix the Trace with the Macros.


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## lil-lynx (31 May 2011)

Amazing, thanks for the informations buddy !
Could you also give me the amount for a 100 liter  tank ?


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## vauxhallmark (31 May 2011)

If the amounts above are for a 120USG (454l) tank, then for a 100l tank you would dose approx 2/9, or even more approximately 1/5 of the amounts above. 1/5 would be very easy, as all the references to 50ml you simply change to 10ml. 

Mark


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## lil-lynx (31 May 2011)

Sounds really silly but which is which. I know KNO3 Potassium Nitrate but what are the other two KH2PO4, MgSO4 

Sorry guys, science wasn't my strong subject


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## lil-lynx (31 May 2011)

Im not ignoring your answer CeeJay its just, the site i bought these of told me this. 

Standard Ei Dosing [This is a guideline only]
Macro Solution
Mix:
3tsp Potassium Nitrate
1tsp Potassium Phosphate
6tsp Magnesium Sulphate
500ml water
Micro Solution
Mix:
1tsp Chelated Trace Elements
500ml Water
Dosing
Macro 3x a week. (10ml per 50ltr of Aquarium water)
Micro 3x a week.  (10ml per 50ltr of Aquarium water)
50% weekly water change.

What do you guys think ?


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## foxfish (31 May 2011)

Cegs calculations will be very accurate http://www.fluidsensoronline.com/calcul ... ive-index/


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## lil-lynx (31 May 2011)

Bookmarked


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## CeeJay (1 Jun 2011)

Hi all


			
				foxfish said:
			
		

> egs calculations will be very accurate http://www.fluidsensoronline.com/calcul ... ive-index/


I always use that one.
Works a treat   

Lil-lynx
Lets do the sums.
10ml per 50l and your tank is 450 litres which is 9 times bigger (than 50l), so you need to dose 9 x 10ml which is 90ml at each dosing.
If you are dosing 90ml 3 times a week that will be 270ml per week. As this bottle is only 500ml it won't even last you 5 dosing days (a week and a bit)
Multiply that all up and you will end up with roughly the figures I gave you for a 28 day supply.


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## Bobtastic (1 Jun 2011)

I'm a little confused...

I have a 240litre tank and using the calculator provide on FSOnline, it tells me that when setting up a 500ml mix of Macro and trace that I have to dose 120ml of each on consecutive days (Macro/Trace/Macro/Trace/Macro/Rest/Rest/WaterChange). That seemed excessively high to me and your numbers above seem to highlight that even more so!


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## ceg4048 (1 Jun 2011)

Bob, this is why we need to understand the fundamental arithmetic of our dosing program. You really ought to study the EI Tutorial. Ask questions if the statements seem unclear. That way you'll have a firmer grasp and will find it easier to interpret any anomalies that arise.

The FluidSensor page quite clearly states that the values being provided are a one week supply:


> 500 ml will provide up to 4 doses for your size tank
> (That is up to 1 weeks supply of Macro solution and
> up to 2 weeks supply of TNC Trace solution)


If this is the case, then only 4 doses worth of macros are being mixed with the water and therefore the total volume of the mix is divided by 4. It doesn't matter what the volume of water is. You can put 4 doses of powder in 4 gallons of water. Each dose will then be 1 gallon but will contain exactly the same number of grams of powder as if you mixed the powder in only 500ml of water.

In the EI Tutorial I elected to make  up a batch that would last 12 doses, i.e. 1 month supply:


> 1 month = 4 Weeks
> 3 doses of NPK per week
> Therefore there are 12 doses of NPK per month.
> ...
> ...


If you understand the fundamentals, then you realize immediately that it's no big deal to multiply the FluidSensor values by 3 in order to get the 12 dose equivalent amount of powder. You can even simply multiply the single dose value of KNO3 (3.7g) by 12 to arrive at about 45g.

Then you can divide the volume of water by 12, i.e. 500/12 which gives you roughly 40ml doses.

it's really important that this makes sense, even if you have to struggle to have it resolved in your brain internally, otherwise we'll forever be tripping over our own shoelaces.

It's not clear to me why they chose a 1 week supply as opposed to a 1 month supply, but that's something you should ask the guys on the FluidSensor forum thread => Bryan's (not very) Secret Project.....UPDATE which they opened a few weeks ago. Due to forum guidelines they can not comment on this thread. 


Cheers,


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