Mixing Mg with NPK or with Traces?

**tchavei** · 04-12-2012, 10:55 AM

Hi

I've been studying the EI method for a few days now (and I finally get the philosophy behind it, I think). I made up a fertilization plan for my 60 liter Aquarium. The plan is to dose NPK and traces three times a week (alternate days between NPK and traces). I've introduced a slight imbalance between the N and K ratio as my aquarium is fully stocked right now (118% according to aquarium advisor). 75% of N in regards seemed quite right as my fauna produces around 10ppm of nitrates weekly. The aquarium itself has a mix of HC cuba, lilaeopsis novae-zelandiae, Echinodorus tenellus and Eleocharis Acicularis. No stem plants (the aquarium is still in the initial stage of its life although fully cycled. I used Elos Bottom Mineral and Terra Zero as a fertile substrate which is covered with a layer of dennerle black substrate (1-2mm grain). I also use pressurized CO2 injection (its at 35 ppm right now - through dropchecker method) and my lights are DIY Leds (Cree XP-G 1500 x 10 - basically the same as two TNC grobeams 600)

The final values I came up with are:

NO3 6.1 ppm per dose (obtained from KNO3)
K 8.0 ppm per dose (obtained from KNO3, KCl and KH2PO4)
P 1.0 ppm per dose (obtained from KH2PO4)

(cumulative values per week with no consumption: N=18.4ppm, K=24.3ppm, P=2.8ppm)

Traces (using Plantex or TNC traces)

Fe 0.241 ppm per dose
(the other components come in the same relationship so no need to list them here).

Now, I also want to add a little Magnesium as my tap water is rather soft I think (Kh=5, GH=6). I was thinking around 0.33ppm per dose (cumulative weekly build up of 1ppm).

I do have doubts if I should add Magnesium to my Macro or to my Micro mix. Is there any significant difference? Does Magnesium react with some of the other components?

By the way, here are two pics of my aquarium so you have an idea what I'm talking about

Thanks for any comments/help

One week old:

two weeks old

I really need to start fertilization before the plants yellow out on me.

Regards

Tony