Leca on hydroponics
What's Happening
Lightweight Expanded Clay Aggregate (LECA) is an inert, non-decomposing growing medium made from fired clay balls 8-16mm in diameter. Unlike organic soil, LECA provides instant drainage, zero compaction, and permanent structural stability. The capillary spaces between clay balls create a dual-zone system: the lower portion maintains a water reservoir while the upper portion remains aerated. Roots grow into the water zone (water roots) or remain in the air zone (air roots), creating a semi-hydroponic environment where the plant controls its own water uptake via capillary action.
How to Fix It
- 1
Pre-rinse LECA thoroughly: Soak in water for 24 hours, agitate, and drain to remove manufacturing dust
- 2
Select appropriate pot: Use pots with no drainage holes (cache pots) or self-watering inserts; clear pots allow root monitoring
- 3
Fill pot to 2/3 with LECA, position plant roots, then backfill with additional LECA around root ball
- 4
Add nutrient solution: Fill reservoir to 1/4-1/3 pot height with pH 5.8-6.2 hydroponic nutrients at 1.2-1.6 EC
- 5
Maintain water level: Refill when reservoir drops to 1/4 original level; complete change every 2-4 weeks to prevent salt buildup
How to Prevent It
Use only high-quality horticultural-grade LECA with uniform 8-16mm sizing. Pre-soak and rinse new LECA for 24 hours to remove clay dust that can clog roots. Maintain water level at maximum 1/4 to 1/3 pot height to ensure adequate aeration zone. pH buffer LECA initially with pH-adjusted water as the clay surface can affect nutrient solution chemistry in the first 2-4 weeks.