Microsiemens and Anthuriums

Probably every one of us has heard the term microsiemens in the context of fertilizing anthuriums. But what does the term microsiemens actually mean? And how can microsiemens be useful for anthuriums?

Basic Information:
Microsiemens (µS) is a unit of measurement. It indicates the electrical conductivity of water, which is caused by mobile ions in the water. In concrete terms, this means how well water can conduct electricity. In direct correlation, it indicates how many dissolved salts (nutrients, minerals) are present. From this, you can indirectly derive the fertilizer concentration.

For example:
1 microsiemens (µS/cm) is a very low conductivity. The higher this value, the more dissolved substances are present in the water. Most often, the value is given or measured in microsiemens per centimeter (µS/cm).

But what does microsiemens have to do with anthuriums (or plants in general)?
Anthuriums are sensitive to salt concentrations in water. Therefore, the microsiemens value is very important for them. If the value is very low (e.g., at 100), it means that hardly any nutrients are present. This can result in deficiency symptoms such as pale leaves or slow growth.

If the value is higher, for example, at 200-600 microsiemens, it means for the plant that more nutrients are available and there is a well-balanced equilibrium between water and nutrients. This can lead to better root growth and stronger leaves.

If the value is very high, for example, at 2000 or higher, too many salts are already present, which increases the risk of root damage (so-called burns). It can also lead to a growth stop of the plant.

How do I measure the microsiemens value?
For this, you need an EC meter (electrical conductivity). You can get these from many online shops. Their prices range from very cheap to very expensive. For us, Bluelab devices have proven to be very good. However, cheaper options are certainly available.

Where do I get optimal water for my anthuriums?
You can collect rainwater or use filtered water (reverse osmosis water). We also have a corresponding entry in our 4Aroids Encyclopedia: Reverse Osmosis Water for Anthuriums
They often have very low µS values. This means they need to be enriched with fertilizer. The microsiemens values of tap water vary greatly from region to region.

Which values are good for which size and phase?
First of all: opinions differ here, and many growers have had different experiences. We recommend that you gradually approach the topic from low to high and observe how your anthuriums react to the microsiemens value used.

We have had good experiences with the following values:
Anthurium Seedlings:
500-800 microsiemens (µS)

Medium-sized Anthuriums:
800-1200 microsiemens (µS)

Adult Anthuriums
1000-1500 microsiemens (µS)

As a general rule: it is better to fertilize a little weaker, but regularly.

In parallel with the microsiemens value, it is advisable to check the pH value and adjust it if necessary. You can find more about this in our 4Aroids Encyclopedia entry pH value and Anthuriums.