Ferrdrakon K Full Potassium Fertilizer

Ferrdrakon K Full Potassium Fertilizer as ready-to-use solution or as refill pack

For strongly planted and strongly lighted pools, potassium can be a limiting factor, as many plants take-up much more potassium than they need.

Some plants react very sensitively to a lack of potassium (e.g. Alternanthera [parrot leaf] - and Ammania [Cognac plant] - species). The symptoms are sudden growth standstill and crippled new leaf growth.
Here the basic fertilizing with Ferrdrakon can be supplemented using Ferrdrakon K that has a higher content of potassium, more magnesium and some calcium.
The content from iron, manganese and other trace elements must be reduced by half compared with Ferrdrakon, because the solubility of the potassium salts is too small, to obtain the desired relationship between potassium, iron and the other trace elements without having to make compromises.


30,000 mg/l potassium, 7,500 mg/l magnesium, 500 mg/l iron, 200 mg/l manganese, 100 mg/l calcium, 30 mg/l boron, 10 mg/l copper, 10 mg/l molybdenum, 10 mg/l zinc, 5 mg/l nickel, 5 mg/l cobalt, 4.6 mg/l iodide, EDTA, HEEDTA, DTPA, NTA or IDHA*, methyl paraben, ascorbic acid

* Please note package information

Daily Allowances by a dosage of 2 ml /100 l of aquarium water

600 µg/l potassium, 150 µg/l magnesium, 10 µg/l iron, 4 µg/l manganese, 0.6 µg/l boron, 0.2 µg/l copper, 0.2 µg/l molybdenum, 0.2 µg/l zinc, 0.1 µg/l nickel, 0.1 µg/l cobalt, 0.092 µg/l iodide


Ferrdrakon K should always only replace a part of the Ferrdrakon dosage. One starts at the calculated or recommended dosage of Ferrdrakon and replaces a part with the double amount of Ferrdrakon K. By using it on its own, the potassium dosage in practically every case would be too high.

For the replaced part the potassium and magnesium dosage is 20 times higher than before.

One should start only with a small part (a sensible amount would be 20 - 30 %) of the Ferrdrakon dose, replaced with Ferrdrakon K and the replaced part should be only slowly increased. The effect should be observed: When there is no more growth improvement and/or problems with algae begin, one must reduce the replaced part-dosage again.

Using a daily dosage is preferred, to avoid a sudden weekly “step-increase” in the concentration of potassium, which can in turn lead to increased algae growth.
Exceptionally, in the case of daily fertilisation with larger water changes, the fresh water can be fertilised directly with half the dose (10 ml / 100 l fresh water).

A pre-requisite for this is that a minimum of 25 % exchange of water takes place every 2 weeks. Of course a greater water exchange does no harm rather is quite a sensible move.

Ideal iron content

0.05 - 0.1 mg/l

Ideal potassium content

10 - 15 mg/l

Excessive overdosing of potassium can cause an exorbitant growth of green algae or insufficiency symptoms by blocking the absorption of magnesium.

Storage Life

Store in a dark cool place (the metal chelate complexes are sensitive to light) - minimum storage life please see database.

The solution that is delivered normally has a light yellow to dark brown colour. After the entry of air, some time later, it can cause the colour to change to dark brown or eventually green-black, but it always remains clear. The effectiveness of the fertilizer is however not affected in any way by this colour change process.

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18 September 2017 16:56

Konnte damit meinem Kalium wer...

Konnte damit meinem Kalium wert endlich auf den Gewünschten Wert von 15ml pro Liter puschen. Mit handelsüblichen Dünger sonst kaum zu schaffen

11 April 2014 11:38

Diesen Dünger benutze ich seit...

Diesen Dünger benutze ich seit Jahren und bin sehr zufrieden mit dem Pflanzenwuchs. Natürlich muss ggf. mit anderen Düngern ergänzt werden. Schlagwort NPK.

6 February 2013 14:37

Das Leitungswasser hat bei mir...

Das Leitungswasser hat bei mir einen extrem geringen Kaliumgehalt. Daher habe ich die Dünung mit Ferrdrakon um ein Drittel reduziert und durch die doppelte Menge Ferrdrakon K ersetzt. Ob das ausreicht, werden die nächsten Wochen zeigen.

1 November 2014 10:06

Das Produkt wird täglich (ein ...

Das Produkt wird täglich (ein paar Tropfen) dosiert. Für jedes Pflanzenaquarium geeignet.

19 November 2014 08:21

Sehr gut...

Sehr gut

23 December 2014 10:53

Pflanzen wachsen mit *** nun p...

Pflanzen wachsen mit *** nun perfekt.

1 January 2016 16:46

1A Dünger...

1A Dünger

29 September 2016 16:30

Für mich gibt es keinen besser...

Für mich gibt es keinen besseren Dünger. Sehr gut auch die klare Angabe der Inhaltsstoffe.

6 October 2016 22:03

Ich benutze das Pulver zum Ers...

Ich benutze das Pulver zum Ersten mal. Bis jetzt hatte ich es Flüssig. War Super. Die Pflanzen Top.

18 July 2022 17:02

Benutze den Dünger bei jedem WW.

Guter Dünger

Some photos from the aquarium of Wilm Thiere from Braunsdorf

Wilm Thiere has always tried to recreate Amano's aquariums.


20 ml Dispensing Beaker for Screwing
Plain dispensing system (capacity max. 20 ml) for measuring the necessary amount of fertilizer or adding water treatment.

1 ml Dispenser pump
For measuring fertilizer or adding water treatment

Programmable single-channel dispenser pump SD-01M
Programmable single-channel dispenser pump SD-01M (peristaltic pump) / 1 - 99 ml per dosing pulse / digital display

Metering valve with venting for canisters
With vent for 3 and 5 litre canisters

Sold out
PRODACtest Fe - Iron
Water test kit for measuring the iron concentration (Fe). Suitable for fresh and marine water. Allows up to 63 tests.

30 ml Canister pump
Dosing pump for 3 and 5 litre canisters


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