Which growing mediums?
The growing media you choose to use comes down to personal preference. Good results can be achieved with many different mediums, but the key features you should look for are:
- Low-medium Water
- Holding Capacity (WHC)
- High Air Filled Porosity (AFP)
Clay pebbles are a good choice for dripper systems as they don’t require anything to be added or mixed in. They have good water retention and plenty of air space between them, creating a high air filled porosity.
Clay pebbles allow for a much higher feed frequency than other mediums, with a low risk of over watering. This frequent feeding cycle allows the oxygen in the root zone to be replenished more often than if it would be using a heavier soil based medium. This abundance of oxygen, water and nutrients leads to greater nutrient uptake and bigger yields.
Coco / Clay pebble mix
If you choose a coco / clay pebble mix, the percentage of coco should be ideally 40-50% of the total volume of the growing media. Pre-mixed media such as Gold Labels HydroCoco 60/40 are ideal for this, as the clay pebbles are pre-washed and evenly distributed throughout the mix.
The addition of coco to clay pebbles increase the water holding capacity of the medium, allowing more time between feeds which means fewer feed cycles per day.
When using compost or any media with medium-high water holding capacity, we highly recommend using an Imperium feed duration controller to shorten the feed duration from the standard 15 minutes on a segmental timer. This will help prevent over watering and water-logging by shortening the feed duration from anywhwhere between 1 second to 15 minutes.
Understanding the feed cycle
To get the best results from your dripper system you must ensure you get the feed cycle right. The feed cycle is made up of 2 elements;
Feed Frequency – This is how often you feed the plant, which largely depends on what type of growing media you’re using and how well established your plants are.
Feed Duration – This is the total time of each feed cycle and will depend on the number of pot in your system and the growing media used.
As with all hydroponic systems, the nutrient strength and feed cycle should reflect your environment. For example; if you’re using clay pebbles and the environment is hot and the humidity is low, these hot and dry conditions will cause the plant to use more water and less nutrient, causing the nutrient strength to rise in the reservoir. In these circumstances we recommend setting the nutrient strength lower than usual to account for rising strength. In these conditions the pots should be flooded more often, up to once per hour.
The same room during cooler conditions, with a higher humidity, will mean higher nutrient strengths can be used and the number of feed cycles can be reduced to once every 2-3 hours. Always consider the effect that the environment will have on your plants and adjust your feeding strategy accordingly.