Interactions between growing media and liquid feed

What are the components in my growing media?

It is important to know that the same components can have different properties if they come from different sources, so it is key to monitor your growing media and talk to your supplier regularly.

Coir fibre

• Coir is naturally lower in pH and is more like peat in its physical properties so behaves in a similar way.
• It can be high in certain nutrients, particularly potassium (K) so it may be possible to have a feed with reduced K content.
• Coir can have high EC overall, so mixes high in coir may not be suitable for sensitive crops.

Wood fibre

• Growing media mixes high in wood fibre may retain less water, so unless more water is needed consider increasing your feed/water ratio in your dosing system.
• Where hard water is used for irrigation, growing media mixes high in wood fibre tend to increase in pH more than others. Monitor for deficiency symptoms and consider a feed with a higher proportion of nitrogen as ammonia (NH4) as it can help to keep growing media pH lower.

Wood fibre as a component of growing media

Perlite

• This is an inert material and when used in a mix does not change the chemical properties of the growing media.
• Growing media mixes high in perlite may retain less water, but unlike wood fibre there is less need consider increasing the feed/water ratio in your dosing system as it will not lock up nutrients.