Fert Calculator Accuracy

[LeMoine]

So I used this calculator: http://calc.petalphile.com/ to determine daily EI dosing for my tank and I was wondering how accurate these are. What makes me question their accuracy is the requirement for an excessive (compared to my N and K dosing) amount of Micros and Phosphorous.
Here are its daily dosing recommendations:
N: 5ml
K: 9ml
P: 28 ml
Micro: 47ml

Keep in mind I am using Pfertz for N,K, and Micro, along with Seachem Phosphorous. The tank is approximately 34 gallons after substrate.

[Darkblade48]

Unfortunately, giving volumes are meaningless without knowing what concentration you intend to mix up your fertilizers at.

If you are looking at dry weight, EI dosing is probably much different compared to the Pfertz recommended dosage, since EI aims to have an excess of nutrients in the water column (that is reset by weekly 50% water changes) so that the plants are not nutrient deficient at any time.

[Zorfox]

Originally Posted by Darkblade48

Unfortunately, giving volumes are meaningless without knowing what concentration you intend to mix up your fertilizers at.

That calculator has an option for DIY or premix. If you choose premix his ferts are listed. The results for dosing are by volume. I checked it out earlier and agreed that it seemed excessively high but had no idea why.

[Darkblade48]

Originally Posted by Zorfox

That calculator has an option for DIY or premix. If you choose premix his ferts are listed. The results for dosing are by volume. I checked it out earlier and agreed that it seemed excessively high but had no idea why.

Got it. In any case, the volumes seem high because EI aims to have excess nutrients in the water column rather than "just enough."

In addition, the volumes will be very high because commercially available fertilizers are usually not very concentrated.

[LeMoine]

Cool, I was just concerned that I was dosing too much. Looks like I will be going the dry fert route next time!