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Alocasia in LECA or semi-hydroponics: how to move it over and when it's not worth it

August 22, 2026

The semi-hydroponics (growing in expanded clay, “LECA”, with a small water reservoir at the bottom) has become the favourite method of many Alocasia collectors for one reason: it almost completely eliminates root rot, which is what kills the most Alocasias at home. In exchange it asks you to understand a little about nutrients and pH. We'll tell you how we do it and for which plants we recommend it.

Why it works well for the Alocasia

• The roots have air always: the clay doesn't compact or waterlog.
• Watering stops being a guessing game: you refill the reservoir when it's empty.
• You see the root through a transparent container: you spot a problem weeks earlier.
• Without organic substrate there are far fewer fungus gnats and fewer thrips larvae.

When it's NOT worth it

• Plants just arrived or stressed: switching substrate to LECA costs roots. Wait until you see a new leaf (acclimatisation).
• In winter or below 18 °C: the new water roots are slow to appear and the corm can rot in the meantime.
• If you're not going to use hydroponic fertiliser: the clay contributes nothing; without nutrients the plant stalls and yellows.
• Very small jewel Alocasias or leafless corms: better in sphagnum or substrate until they have 2-3 leaves.

Step by step

1. Prepare the clay

Rinse the LECA until the water runs clear and soak it for 24 hours: dry, it absorbs water from the root. Use a container without holes (transparent is better) or the two-pot system (inner one with holes, outer one watertight).

2. Clean the root

Take out the plant, remove all the substrate with lukewarm water and cut off any soft or brown root. It's fine to lose some fine roots; the soil ones usually die and the plant makes new water-adapted roots in 2-4 weeks.

3. Place it and set the water level

Put down a layer of clay, the plant on top with its roots spread out and fill in around it. The water level should stay below the roots for the first few days (the clay wicks moisture up by capillarity) and never touch the corm. A third of the pot's height is a good reference.

4. Nutrients and pH

Use a fertiliser specifically for hydroponics (soil ones don't carry all the micronutrients in available form) at the manufacturer's low dose with each refill, and water with a pH between 5.5 and 6.5: with very hard tap water the iron gets locked out and the new leaf comes out yellow between the veins. Every 3-4 weeks empty the reservoir, rinse the clay with clean water to flush out salts and refill.

5. The first weeks

High humidity and a warm spot (22-26 °C). It's normal to lose an old leaf. When you see new white roots, thick and with little hairs, it's adapted and you can raise the reservoir to the normal level.

Corms in LECA

For corms that already have roots and a leaf, LECA works very well: less risk of rot than forgotten sphagnum. For rootless corms we still prefer the tub method with sphagnum that we explain in how to sprout a corm, and move them to LECA afterwards.

Our plants leave home in airy substrate; if you want to move them to semi-hydro, do it in spring or summer and after the first new leaf. Any questions, info@marinasjunglegems.com.

Texto redactado con ayuda de inteligencia artificial y publicado por el equipo de Marina’s Jungle Gems.