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.

10 of 39 reviews

Average rating of 4.9 out of 5 stars






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6 October 2016 22:03

Review with rating of 5 out of 5 stars

Ich benutze das Pulver zum Ers...

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

17 February 2014 10:12

Review with rating of 5 out of 5 stars

Kombiniert mit Ferrdrakon Top...

Kombiniert mit Ferrdrakon Top Düngesystem

27 June 2024 00:00

Review with rating of 5 out of 5 stars

Bewertung ohne Text

Bewertung ohne Text

15 June 2014 12:22

Review with rating of 5 out of 5 stars

Pflanzen reagieren sofort. End...

Pflanzen reagieren sofort. Endlich wieder gesundes Wachstum und keine zu kleinen und braunen Wüchse.

1 November 2014 10:06

Review with rating of 5 out of 5 stars

Das Produkt wird täglich (ein ...

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

19 November 2014 08:21

Review with rating of 5 out of 5 stars

Sehr gut...

Sehr gut

23 December 2014 10:53

Review with rating of 5 out of 5 stars

Pflanzen wachsen mit *** nun p...

Pflanzen wachsen mit *** nun perfekt.

1 January 2016 16:46

Review with rating of 5 out of 5 stars

1A Dünger...

1A Dünger

29 September 2016 16:30

Review with rating of 5 out of 5 stars

Für mich gibt es keinen besser...

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

18 July 2022 17:02

Review with rating of 5 out of 5 stars

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.


Average rating of 4.7 out of 5 stars

20 ml Dispensing Beaker for Screwing
Simple metering system for dosing fertiliser or water conditioner


Average rating of 4.5 out of 5 stars

1 ml Dispenser pump
Measuring the required quantities of fertiliser or water conditioner

Programmable single-channel dispenser pump SD-01M
Peristaltic pump with 1 - 99 ml per pulse and digital display


Average rating of 5 out of 5 stars

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

Sold out
PRODACtest Fe - Iron
Determination of iron (Fe) concentration. For fresh and sea water.


Average rating of 4 out of 5 stars

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


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