# Are AquariumPlantFoods recommended EI dosages sufficient?



## PedroB (23 Dec 2017)

Good afternoon all,

Ever since I returned to the hobby I've been dosing the recommended 10ml per 50L every other day of the EI starter kit by APF. (http://www.aquariumplantfood.co.uk/fertilisers/dry-chemicals/starter-kits/ei-starter-kit.html)

Lately I tried planting some hygrophila pinnatifida, and after a couple of weeks they started displaying pinholes and stunted growth,

I've since reduced the light and increased CO2 injection and flow (went from 750lph filter to 2000lph and 4x39w light to 2x39w, 128litre tank) and the issues still continue.

I've got a decent HC carpet and most of the rest of the plants are doing well, so I started looking for other culprits.


According to the EI philosophy, we should dose weekly:
Nitrate (NO3) 20ppm per week
Potassium (K) 30ppm per week
Phosphate (PO4) 3ppm per week
Magnesium (Mg) 10ppm per week
Iron (Fe) 0.5ppm per week

But, if for simplicity we consider a teaspoon to weigh 6g, the recommended APF mix gives us per dose:

Nitrate: 5.9ppm (17.7 per week)
Potassium: 4.4ppm (13.2 per week)
Phosphorous: 0.54ppm (1.62 per week)
Magnesium: 1.45ppm (4.35 per week)
Iron: 0.15ppm (0.45 per week)

(Using this calculator http://www.aquariumcalculators.com/parts-per-million/stock-solution-ppm-calculator/)

I know I should not be fretting about numbers, and I've simply started dosing double what APF recommend, I'd just like some understanding as to why they recommend those values or for someone to point out where I got it wrong.

Cheers, looking forward to your contributions.


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## Zeus. (23 Dec 2017)

Yes they are enough and no they are not

good enough for most but not for all, depends on what your growing level of [CO2] and PAR output of light.



PedroB said:


> Lately I tried planting some hygrophila pinnatifida, and after a couple of weeks they started displaying pinholes and stunted growth



Two weeks is just about the time it takes for them to adjust to the CO2/new tank, plus it also takes time for the plant to adjust to the light intensity, during which time it is stressed also so in the first two weeks some plants melt/pin holes etc if stressed too much but most make a recovery. I have some P Helferi which was in a tank with High CO2 so transferred some to another High CO2 tank, in the original tank the Helferi continue to do well but in the other tank it wasn't doing well at all leaves coming off and roots not showing any signs of growth. Four weeks later and nearly gave up on it started to grow new roots and leaves started to pick up that was this week so Im hopeful now. So it takes time 

Yes you can double dose what APF advise without any issues except your salts dont last as long.

Think it just needs more time to adjust


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## PedroB (23 Dec 2017)

Thanks for your reply Zeus.

I've had the same issue with P Helferi which is now perking up. 

It's just confusing to me that a company would recommend half the amount that EI actually calls for, especially since they are the ones that sell the product, and in my mind would be interested in selling more product.

I've now used this calculator, which is giving me much more realistic calculations.


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## Tim Harrison (23 Dec 2017)

Pinholes in the old leaves of _H. pinnatifida_ have variously been attributed to...

potassium deficiency
Chloride deficiency - chloride facilitates the uptake of potassium...apparently
Low CO2 and/or poor flow and distribution
Micronutrient toxicity (Clive would definitely disagree with this, but some have reported success by reducing micronutrients)

Either way it can be temperamental, I've had some success with it but it didn't exactly thrive.


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## PedroB (23 Dec 2017)

Thanks for your reply Tim. 

The issue with the H. Pinnatifida was only the catalyst for my search, not the main issue. 

The main issue for me is why would APF recommend such a meager regime under the EI philosophy, which aims for "infinite" amounts of nutrients.


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## Tim Harrison (23 Dec 2017)

Sure, got that. Your other plants seem to be doing well so I guess generally speaking the dose wasn't that far out; _H. Pinnatifida_ can be demanding and prove the exception to the rule. 
But I hope upping the dose sorts it out. If it doesn't at least you have other avenues to explore


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## Zeus. (23 Dec 2017)

PedroB said:


> It's just confusing to me that a company would recommend half the amount that EI actually calls for, especially since they are the ones that sell the product, and in my mind would be interested in selling more product.



Well EI is only an estimate, think the company works on the basis of what is enough for most, yes there isnt an issue with using  a lot more, except then the company would be blamed on using too much salts for their EI Mix to improve sales, so they cant win. It also does state on APF EI dosing instructions that it is a guideline only


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## PedroB (23 Dec 2017)

Don't take me wrong, I've always been a happy customer of theirs, I just wish there was some mention in the instructions. 

I guess they think that if you're advanced enough in the hobby you'll figure it out by yourself.


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## ceg4048 (4 Jan 2018)

PedroB said:


> I know I should not be fretting about numbers, and I've simply started dosing double what APF recommend, I'd just like some understanding as to why they recommend those values or for someone to point out where I got it wrong.


Exactly. Fretting about numbers when dosing nutrition is the worst mistake you can make.

The reason we use a number like 20 ppm is because it's an easier number than 17.7 ppm, which is is not only a ridiculously awkward number, but will also never improve chances of success compared to numbers such as 17.6 ppm or 21.3 ppm.

All these numbers such as 6 gram per teaspoon are estimates. Do you use a level teaspoon, a full heaping teaspoon, or somewhere in between.?
What was the purity of the powder supplied?
What was the humidity at the time of dosing or in the container? Some salts are hygroscopic and will retain more water thus reducing their concentration.
How much water is actually in the tank? Less water raises the concentration. 
How many people know the answers to these questions or have consistent control on a day-to-day basis?

Even being off by 20%-30% will not really make a difference. That's how much margin of error there is in this dosing program.
If you are dosing these values and if you still have a nutrient related problem then you need to look elsewhere for your problem, such as flow or distribution. That's how robust the dosing program is.

One also needs to ensure that the problems being observed is actually a nutrient issue. Far too many people confuse nutrient related issues with CO2, excessive lighting, or maintenance related issues.

Cheers,


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