Testing Potassium for Perfect Plant Growth

Potassium is one of the macroelements which is quickly and effectively absorbed within a few hours and temporarily stored by plants in freshwater. In growing plants the demand for potassium is higher than other elements. As a result, potassium concentrations can drop to a minimum range, causing plant growth to stagnate, even if the aquarium water is fertilised regularly (e.g. weekly). Potassium levels in mains water are usually too low compared to those in natural biotopes, particularly in relation to calcium and magnesium concentrations.

How often should you test?

Firstly we recommend you measure the potassium content of your aquarium water daily. This way the plants’ needs can be determined and the fertiliser can be dosed appropriately. After that you can continue the routine measurements less frequently.

What is the ideal content?

For good plant growth the value needs to be approximately 5 - 10 mg/l, for aquariums with high power lighting (from about 1 W/l illuminance) between 10 and 30 mg/l. Higher potassium levels in the aquarium will lead to the growth of green thread algae.

Action, when too much or not enough

Potassium content too low (< 5 mg/l): Fertilisation with JBL PROFLORA Ferropol , JBL PROSCAPE Fe +MICROELEMENTS and especially daily fertilisation with JBL PROSCAPE K MACROELEMENTS .

Potassium content too high (> 20 mg/l): Repeat measurement after 24 hours. If value is still too high, carry out an adequate water change.

How is the test carried out?

This short video shows you how easy it is to carry out the JBL K Potassium Test .

© 07.09.2017
Matthias Wiesensee
Matthias Wiesensee
M.Sc. Wirtschaftsinformatik

Social Media, Online Marketing, Homepage, Kundenservice, Problemlöser, Fotografie, Blogger, Tauchen, Inlineskating, Aquaristik, Gartenteich, Reisen, Technik, Elektronische Musik

About me: Seit Teenagerzeiten mit Aquarien in Kontakt. Klassische Fischaquarien, reine Pflanzenaquarien bis hin zum Aquascape. Aber auch ein Gartenteich und Riffaquarien begleiten mich privat im Hobby. Als Wirtschaftsinformatiker, M.Sc. bin ich als Online Marketing Manager bei JBL für die Bereiche Social Media, Webentwicklung und der Kommunikation mit dem Anwender der JBL Produkte zuständig und kenne die JBL Produkte im Detail.


A word about cookies before we continue

The JBL Homepage also uses several types of cookies to provide you with full functionality and many services: We require technical and functional cookies to ensure that everything works when you visit this website. We also use cookies for marketing purposes. This ensures that we recognise you when you visit our extensive site again, that we can measure the success of our campaigns and that the personalisation cookies allow us to address you individually and directly, adapted to your needs - even outside our website. You can determine at any time - even at a later date - which cookies you allow and which you do not allow (more on this under "Change settings").

Are you over 16 years old? Then confirm the use of all cookies with "Noticed" and you are ready to go.

Choose your cookie settings

Technical and functional cookies, so that everything works when you visit our website.
Marketing cookies, so that we recognize you on our pages and can measure the success of our campaigns.