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What you need to know about Expanded Clay (LECA)!

LECA stands for lightweight expanded clay aggregate. To put it simply, Leca comes in baked

clay balls, hydroponic clay balls
Reusable LECA Clay Balls

clay balls that soak up a little water, after which they expand slightly. It’s a growing medium like soil, used to grow plants. Unlike soil, Leca is a collection of clay soils and doesn’t contain any nutrients. It’s odourless, eco-friendly and reusable. These little clay pebbles can impressively hold up to 4 times their weight in water, and they allow air and water to move freely throughout the growing medium leaving space for your plants to breathe.

What are the Benefits of Using Leca?

It’s an Extremely Porous Medium

Leca’s porous nature makes it an excellent drainage material for your growing medium. Clay pebbles are designed to wick up water and drain it out into the bottom of the pot while allowing air to move freely throughout medium mixture. This ensures that roots get enough air to stay healthy while remaining fully saturated with water.

Less Risk of Root Rot

Leca is a porous material that absorbs water and air into its internal structure. This helps promote healthy root development by allowing the roots to easily breathe even as they sit in a constantly moist environment. Roots tend to rot when oxygen isn’t able to circulate throughout the growing medium. Leca helps prevent this from happening by keeping the soil aerated and allowing the roots to fully exchange CO2 for O2.

Growing Plants Hydroponics Saves Water

One of the most common problems hydroponic gardeners have is that their plants are drying out. This usually happens because the water being fed to the roots is evaporating into thin air through the drainage hole. Leca can help prevent this from happening by keeping moisture trapped near the roots, where it belongs.

The Leca Balls can be Recycled

What makes Leca a good investment is its sustainable use. After growing a consumable plant like a vegetable, you can use the clay balls to grow another one in another pot using a hydroponic system.

Leca is Environmentally Friendly

When you compare Leca with potting mix, there is one aspect that Leca will always win. Leca is reusable and durable. Even without considering the environmental impact of peat moss, the fact that you can reuse leca makes it a more ecological sound medium than potting soil.

Unlike potting mix, which breaks down over time, you can use leca over and over again.

Less Mess

Unlike soil, leca requires much less water than potting mix and doesn’t become a grimy mess while you’re repotting your plants. Leca is also easier to spill, thanks to its lightweight properties.

The Risks of Pests are Reduced

One of the most common problems with soil-based potting mix is that it’s so easy for pests to become established in it. The warmth and moisture present in the soil make it perfect breeding conditions, while the organic matter provides lots of nutrients for pests to thrive on. In leca, the plant also chooses when to drink water and avoid being overwatered. This means that bugs won’t be attracted to the rotting roots and soil.

Fertilising is More Cost-Effective and Environmentally Responsible

Hydroponic fertilizer can hold water as the soil does, but it’s also soluble so that you can get better uptake by your plants. Because hydroponics use flood and drain systems, the salt concentration is maintained at very low levels, reducing the risk of plant burn.

How to prepare LECA before use

LECA wicks water very effectively. If roots come into contact with very dry LECA, it will wick water away from the roots and can cause the roots to desiccate. Always make sure they are well soaked before use.

Treating LECA before you use it is a must, this ensures your plant can begin it’s Hydroponic life with a healthy start. If LECA isn’t soaked properly it can cause a plant to grow a lot slower than it should.

Step 1: Rinse the LECA Remove the LECA from the packaging and give it a thorough rinse to get all debris and clay dust off.

Pro tip: Use a mesh laundry bag and a garden hose and do this outside.

Step 2: First Soak Soak the LECA for 24 hours using tap water. This first soak will get the first wave of the crud out of the LECA. Pro tip: You can observe the PPM of the soaking water after this first soak.

Step 3: Second Soak Dump out the soaking water and replace with fresh tap water / hose water. Soak for an additional 24 hours. After this soak you can use your LECA!

Pro tip: The second soak usually results in about 300 - 400PPM after 24 hours. Remember in high school science class where you learned about the Law of Chemical Equilibrium? Yeah, no me neither.... Basically, when you put your LECA (product) together with water (reactant) the water and chemicals within the LECA wants to be at equilibrium with the water outside of it until it’s equal inside and outside. If your water is at 100PPM and your LECA is at 800PPM, over time your water will measure higher in PPM and your LECA will measure lower in PPM. The reason for the second soak is to speed up the process. Soaking 800PPM LECA in water that is 100PPM versus 400PPM, the 100PPM will go a lot faster, and the equilibrium point will be lower.

Step 4: Dry and Store Drying and Storage is recommended if you’re not going to use the LECA right away. You can dry the LECA in the mesh laundry bags, they allow for amazing airflow! If you plan on using the LECA right away, skip this step.

Pro tip: You can also add CalMag (Calcium Magnesium supplement) to the soaking water, as well as any rooting hormone. Adding these supplements can happen as early as the first soak, as the Ca and Mg ion substitute for the less desirable soluble minerals in the LECA.


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