# EI Dosing Levels



## JAX3000 (19 Nov 2020)

Sorry if this had been covered. It may be such a stupid question it wasn't even mentioned due to bleeding obviousness...
Anyway, here's my question...
In a Co2 injected, heavily planted tank, with increasing light levels as the tank matures and grows in, I am using Aquarium Plant Food ei kit, following the recepe and exact dosing levels. Is this just a starting point and I should add to this as plants grow, or is this it and in theory I'll never need to increase the dose...?
Thanks in advance.


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## Jayefc1 (20 Nov 2020)

For me its  good starting point and as you get more confidence then start to adapt your recipe to what the plants need more ie lowering the kno3 for better reds in plants


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## PARAGUAY (20 Nov 2020)

It's a good question .Because although plants all need the full range of micros and macros it differs in that it's mainly for CO2 aquariums with dosing as recommended ( Tom Barr) to ensure plants always have nutrients available so as plants tell you by increased healthy growth it can be increased , personally l would gradually do this.The ADA approach is lesser liquid fertiliser with that system. But it uses very rich nutrient loaded substrate.


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## Wookii (20 Nov 2020)

JAX3000 said:


> Sorry if this had been covered. It may be such a stupid question it wasn't even mentioned due to bleeding obviousness...
> Anyway, here's my question...
> In a Co2 injected, heavily planted tank, with increasing light levels as the tank matures and grows in, I am using Aquarium Plant Food ei kit, following the recepe and exact dosing levels. Is this just a starting point and I should add to this as plants grow, or is this it and in theory I'll never need to increase the dose...?
> Thanks in advance.



As I understand it the the APFUK kit is based on standard EI dosing levels. Those levels were designed to ensure you never have a nutrient deficiency, no matter the plant mass or light levels, and always have a nutrient excess. As such you should never need to increase the dosing beyond those levels, as you'll just end up with a greater excess.

You can move the other way though, and reduce the dosing levels, or change the ratio of salts added to the mix as Jay points out. However be aware this is a fairly advanced area, and you want to make any changes slowly so you don't risk a deficiency and resulting plant issues and possible algal outbreaks.


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## Zeus. (20 Nov 2020)

Heres a comparison of APFUK advised starter kit dose levels and Clive's dose and 'Full' EI dose






Zeus.


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## JAX3000 (21 Nov 2020)

Thank you all for your advice... maybe not such a stupid question after all.
I completely agree Wookii, I don't really want to get into tailoring my recipe at this early stage, as I'm more likely to just balls the whole thing up, with my limited experience. However, looking at the comparison chart (thanks Zeus, for SUCH a helpful little chart!) I'm surprised to see the differences, so I guess I could choose, in time, to bring my recipe more in line with Craig's or "full ei" and maybe even slightly increase dosing at a later stage, but for now, I'm on cruise control and I'll just see how that goes.

Thanks again. I find this forum so full of genuine helpful experienced people, who want to share. Much appreciated.


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## Zeus. (21 Nov 2020)

Dosing at Clive's levels or full EI for RO water and your plants shouldn't be deficient in any nutrients.
If you have hard/very hard water things get a little more complex/harder IMO


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## JAX3000 (22 Nov 2020)

Zeus. said:


> Dosing at Clive's levels or full EI for RO water and your plants shouldn't be deficient in any nutrients.
> If you have hard/very hard water things get a little more complex/harder IMO


Hi,
I have hard water... so are you saying I should therefore not use Clive's or Full EI, as that's more for RO or soft water and I should just stick to the APFUK regime?
Thanks


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## dw1305 (23 Nov 2020)

Hi all,


Zeus. said:


> If you have hard/very hard water things get a little more complex/harder IMO





JAX3000 said:


> I have hard water... so are you saying I should therefore not use Clive's or Full EI, as that's more for RO or soft water


No, it is just down to the greater likelihood of <"solubility issues"> in alkaline (high dGH & high dKH) water. Because you have more OH-, Ca++ and HCO3- ions in hard water, there is a greater likelihood of insoluble compounds forming. Examples would be <"calcium phosphate" (Ca3(PO4)2)>, iron hydroxide, iron carbonate, <"iron phosphate"> etc. 

As that indicates problems are most likely to come with <"iron availability">.

The hardness of the water doesn't make any difference for some nutrients, like nitrate (NO3-) and potassium (K+), all their compounds are soluble, so when you add potassium nitrate (KNO3) to water (of any hardness) those ions remain in solution. 

You can still get issues with the ratio of the cations, a very high Ca : Mg, or Ca : K, ratio may effect the uptake of the less common ion, in this case it is <"just a numbers game">.

cheers Darrel


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## JoshP12 (23 Nov 2020)

JAX3000 said:


> Hi,
> I have hard water... so are you saying I should therefore not use Clive's or Full EI, as that's more for RO or soft water and I should just stick to the APFUK regime?
> Thanks



A practical approach may be to dose "Full EI" and use @dw1305s duckweed index to determine the amount of Ca and Mg (and maybe potassium) that you need to add (this would be in the form of DIY salts or GH booster). Maybe omit the KH part though. 

If you come to issues, re-evaluate from there. 

It worked for me!

Josh


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## Zeus. (23 Nov 2020)

JAX3000 said:


> Hi,
> I have hard water... so are you saying I should therefore not use Clive's or Full EI, as that's more for RO or soft water and I should just stick to the APFUK regime?
> Thanks



Clive based his advise for folks using tap water so there was no need for adding Ca as there's enough already in the tap water and the KH of the water was accepted as it was, even the soft water which some folk get have plenty of Ca and minor/trace nutrients for our plants. Clive was a big fan of keeping things simple, *dose in excess* , a *stable [CO2],* *good* *Flow* and *watch your plants.*

If using RO water you have strippped the water of nearly every nutrieint so you need some Ca and the Kh needs addressing, as getting a stable [CO2] without losing livestock can be very tricky to say the least with low KH water. Alos using RO water you will need to address the Ni and Co of the water too, which is why most folk blend their RO water with tap water so they get the trace elements for free. But EI dosing is a more comprehensive (but not complete) dosing regime that contains most of the nutrients you ill need to add esp if using RO water.

If using 100% RO water I would advise EI dosing with root tabs which should cover all the nutrients your plants need.

Hard water is tricker for the reasons Darrel mentioned


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## JAX3000 (23 Nov 2020)

Hi and thanks for all your comments, I'm getting somewhere here...


dw1305 said:


> As that indicates problems are most likely to come with <"iron availability">.


So, just in case this is an issue, I may as well add extra cheated iron from APFUK...?



JoshP12 said:


> A practical approach may be to dose "Full EI" and use @dw1305s duckweed index to determine the amount of Ca and Mg (and maybe potassium) that you need to add (this would be in the form of DIY salts or GH booster). Maybe omit the KH part though



This is edging into a-bit-complicated-for-me territory, but as I understand it the duckweed index is the use of floating plants to expose any deficiencies, having excluded co2 and light, as they are abundant at the surface...? I'm not sure I would know what the hell to do if I did see an issue, as I wouldn't know what I was deficient in! The word duck weed sends a shiver down my spine but I assume other, more attractive, less invasive floating plants would serve the same purpose? I'm putting this in the maybe something soon category for now - thank you.




Zeus. said:


> If using 100% RO water I would advise EI dosing with root tabs which should cover all the nutrients your plants need.
> 
> Hard water is tricker for the reasons Darrel mentioned


 I'm 100% tap water, (although I am filtering out Nitrate and Phosphate, as I believe they are excessive in my water, I also run an unplanted cichlid tank plus it gives me a more stable starting point to work from, also my planted tank is quite heavily stocked and nitrates could otherwise run away... My nitrate was about 40ppm at water change day last week as it is...) In any case, I'm tap all the way.

So, in conclusion (for now) maybe I should aim for a combination of the APFUK and Clive methods listed in the chart Zeus posted here. That is to say APFUK nitrate level and Clive everything else... plus cheated iron supliment.
Does this sound like a logical safe starting point to work from?


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## dw1305 (23 Nov 2020)

Hi all,


JAX3000 said:


> may as well add extra cheated iron from APFUK...?


It depends how hard your water is. If your water has a high pH and carbonate hardness you may need <"FeEDDHA"> or FeDTPA as your iron chelate.


JAX3000 said:


> The word duck weed sends a shiver down my spine but I assume other, more attractive, less invasive floating plants would serve the same purpose?


Originally I used Duckeed (_Lemna minor) _as my floating plant (hence the "Duckweed Index"), but I agree it does have a number of issues. These days I recommend <"Amazon Frogbit"> (_Limnobium laevigatum_) <"as an improved "Duckweed">.  I started with floating plants because I was looking at <"phytoremediation of waste water">.


JAX3000 said:


> although I am filtering out Nitrate and Phosphate, as I believe they are excessive in my water


Most of SE Britain does have high <"levels of nitrate and phosphate"> from sewage treatment and agricultural run-off, but I would still just have more plants mass. Plants are much more effective at nutrient depletion than most purveyors of anion exchange resins, forums and web sites would have you believe.

cheers Darrel


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## Flukeworld (8 Feb 2021)

If I understand the answers on the poster's question - the plant mass does no matter and the consumption would never overcome the recommended dosing levels. I strongly believe its not the case, but I am a "newbie" in the new modern high tech aquarists.
Sounds as if I have 2 plants and 200 it would cost the same dose per litter. I would never agree if there are no pictures included


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## Sammy Islam (8 Feb 2021)

Flukeworld said:


> If I understand the answers on the poster's question - the plant mass does no matter and the consumption would never overcome the recommended dosing levels. I strongly believe its not the case, but I am a "newbie" in the new modern high tech aquarists.
> Sounds as if I have 2 plants and 200 it would cost the same dose per litter. I would never agree if there are no pictures included


Dosing to EI levels assumes you have a heavily planted tank which i guess is 70%+ of the substrate covered). 

Yes technically the dose would be the same regardless of if you had 2 or 200 plants. But you wouldn't need to dose EI if you have a few plants as most commercial fertilisers will be plenty.


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## Flukeworld (8 Feb 2021)

Sounds good. I have no experience with EI method commercial products, so there comes my confusion. Thank you for the logical answer.


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## ceg4048 (9 Feb 2021)

Sammy Islam said:


> Dosing to EI levels assumes you have a heavily planted tank which i guess is 70%+ of the substrate covered).


Hello,
        EI does not care how many plants are in the tank. This is another myth of whose origin is unknown. The concentration goal is to account for the lighting levels, to ensure nutrition is non-limiting, and a side benefit is to produce a nutrient partial pressure which assists in uptake across the leaf surface.

A high plant mass is suggested in general, not just for EI dosed tanks because plants accelerate the biological infrastructure of the tank, therefore more plant mass means better chemical stability.

Cheers,


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## Flukeworld (9 Feb 2021)

Hello Clive,
Can you elaborate more on this "nutrient partial pressure" - seems as maybe I am missing something in my theory knowledge, or its my English skills gap I am having hard time filling up.


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## ceg4048 (10 Feb 2021)

Hi Fluke,
              Concentration of any solute (say sugar, for example) in a solvent (say water)  actually has the effect of exerting pressure on the walls of the container in the same way that the solvent itself exerts pressure against the walls (or against any object in the water).

When you inflate a balloon with your breath there is pressure inside the balloon, yes? Well some of that pressure is due to the CO2 in your breath, some of the pressure is caused by the Nitrogen and other gasses in your breath. 

So for example, if you breath exerted 1 bar of pressure in the balloon then 75% of that 1 bar (0.75 bar) is caused by Nitrogen because 75% by mass of the air you are exhaling consists of Nitrogen and of course that is directly a result of the concentration of Nitrogen in your breath. So the 0.75 bar is the partial pressure of Nitrogen and the remaining gasses will account for the remaining 0.25 bar according to their concentration in the balloon. Each gas will exert it's own partial pressure based directly on it's concentration.

When we dissolve CO2 in water it requires pressurized CO2 to push the CO2 into the solution, yes? Well that CO2 keeps its pressure and so now, some of the pressure that the water exerts against a the walls of the tank and against the leaves that are submersed in the tank is due to the dissolved CO2 that is in the water. It may only be 30ppm but that equates to some of the pressure in the water.

So now it's the same with nutrients. If you dissolve nutrients in the water those dissolved particles exert a small amount of pressure against anything that is in the water. It won't be nearly as much as the rest of the pressure caused by the water molecules but it will be some small amount and the more nutrients that get dissolved exerts more pressure inside and will account for a greater percentage of the pressure being exerted against our leaf. This higher partial pressure pushes into the leaf, which has a lower concentration of nutrients and therefore which has a lower partial pressure of those nutrients.

I hope this makes partial sense at least...🦊

Cheers,


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## Flukeworld (10 Feb 2021)

Thank you, Clive. Makes sense.
On first read I got this image in my head for how we push plants to consume more


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## bsagun (23 Feb 2021)

Zeus. said:


> Heres a comparison of APFUK advised starter kit dose levels and Clive's dose and 'Full' EI dose
> 
> View attachment 156631
> 
> Zeus.



Hi Zeus, this is a useful table, thanks.  
I've been trying to calculate the concentration of nutrients i am currently adding (specifically Mg at the moment) due to issues described here.  I am using APFUK starter kit with a reduced dose for a low tech tank.  

As part of this i was effectively duplicating your table by working out the ppm of APFUK recommended dose, however, im coming up with different results.  The result from the calculator is half what your table suggests.  Am i using the calculator incorrectly, or are different assumptions being made between the two?

For example, APFUK dose is 3 times per week of micro/macro (ie 40ml 3 times a week in my 200l tank).  From the calculator pic below, this gives 3.63ppm in a week (1.21*3).  However, your table is almost exactly twice that, has your table calc assumed dosing 6 times per week perhaps?    

Just trying to understand which one is right, or if im not using the calculator correctly.  

Thanks


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## Andy Pierce (23 Feb 2021)

The calculator is correct, but it's also possible that the APFUK recommendations may have changed over time.  If you go with the current 'starter kit' recommendation for a 500 ml stock solution of:
KNO3 (4 tsp)​KH2PO4 (1 tsp)​MgSO4-7H2O (6 tsp)​you wind up with *weekly* concentrations of:
K 13.4 ppm​NO3 17.7 ppm​PO4 5.5 ppm​Mg 3.6 ppm​By the very nature of EI dosing, you shouldn't have to be radically concerned by the exact values and almost any version of EI dosing will be "good enough", but that being said I can't resist messing with it so I actually use (the APFUK recommendations in parentheses):
KNO3 (4 tsp) -> 3.5 tsp​KH2PO4 (1 tsp) -> 0.5 tsp​MgSO4-7H2O (6 tsp) -> 8 tsp​K2SO4 (0 tsp) -> 5 tsp​which does:
K 24.6 ppm​NO3 15.5 ppm​PO4 2.8 ppm​Mg 4.8 ppm​plus whatever comes along for the ride with the SCAMBS local water supply (which they claim is 30 ppm NO3; no figures given for any of K, PO4 or Mg).


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## bsagun (24 Feb 2021)

Thanks for the reply Andy.  Agree try not to get too hung up on specifics, really just want to compare the ppm between what i've been dosing and other regimes.  I think some of it might be using the teaspoon measure and it's assumed weight, which unsurprisingly can vary.  I've just found the brilliant IFC Calculator where all the units are in grams, so might have to get a digital scale to make sure im comparing like for like with the calculator.


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