More pros and fewer cons make Leca clay pebbles/Hydroton a popular grow medium. Also known as LECA clay pebbles, Hydroton is regarded as a standard growing medium for Aquaponics, Hydroponics, and Aeroponics. We’ll learn about this medium in detail, from Introduction to pros/cons and do’s/don’ts in this post.
What is Leca Clay?
LECA is short of “light expanded clay aggregate” is a processed ceramic lightweight aggregate composed of small pebbles of the size of peanuts. Also known as Hydrotron, LECA is widely used in hydroponics using media bed or Dutch bucket techniques because of its lightweight and other favorable features. Clay pebbles are very popular among aquaponic farmer too.
How is it made?
Leca/Hydroton is made by heating certain clays to a high temperature of almost 1200°C in a rotary kiln. This process expands the volume of material by 4-5 times creating ceramic pellets having a cellular inner structure. It is Green, Anti-shrinkage, Internal curing, Lightweight, Sound, and Thermal Insulation and Fireproofing.
- Crushing Strength =3,1 n/mm²
- Density= 403 kg/m³
- Size: 8-12 mm
Uses of Expanded Leca Clay Pebbles
- They are widely used as a growing medium in the hydroponic/Aquaponics system because of neutral pH and excellent capillary action qualities. Ideal for ebb & flow systems, this medium provides many benefits in comparison with soil. This clean and odor-free medium is reusable and provides excellent aeration.
- Leca is also mixed with Coco Medium and Soil to grow plants in Pot Culture. This is used anywhere where extra drainage is required. Also used in drainage layers in flower pots, roof gardens, for trees in an urban setting and sports grounds.
- This highly porous growing medium is also used for Substratum cultivation in professional horticulture and the cultivation of decorative plants. The plant baskets and container gardens are filled with hydroton to provide support for plants’ roots.
- Use clay pebbles as Seed starter: You can cover the seed with a couple of crushed pebbles in small net pots. The crushing increases saturation. Set the misters to water for 4-10 seconds after every 2-3 hours to set out the germination. Keeping the pebbles moist is important, just don’t let them dry out.
Hydroton prevents root rotting, acidity, and pests.
How to Use Clay Pebbles: Do’s & Don’t
The clay pebbles are the most favorable medium for flood & drain systems. We have listed some do’s and dont’s to consider while working with them. When using for hydroculture (Aquaponics/ Hydroponics/ Aeroponics):
- Rinse new hydroton once with clean lukewarm water before using as there can be dust that may cause clogging issues in drippers or mesh filters.
- Sometimes clay pebbles float! Nothing to worry here! especially newly bought ones. It is normal and you can soak the pebbles for at least 6 – 24 hours. You can hold them down by putting something heavy on top.
- Remove the dirt as much as possible from the roots of the plant.
- Spread a 3-4 cm thick layer of hydroton in the plants’ container.
- Put the plants in the container and fill it with pebbles until a water margin of 2cm is left. Move the plant gently up and down to spread clay all around the roots while While topping up.
- Try to keep an inch (or as much as possible) of dry balls on the top to protect the system from fungus and algae growth.
- During the first week only apply water. Subsequently, add hydro-fertilizer.
- Rinse, soak, or sterilize with isopropyl alcohol or peroxide before reusing the pebbles.
- Never let your pebbles dry out.
- You can use pebbles in conjunction with soil but not as a substitute for soil outdoors.
Pros of Hydroton
Cons of Hydroton
Since these can be somewhat pricey, it seemed fair to let everyone know of any possible Pros.
Alternatives & Comparison
Hydrocorn vs Hydroton
Comparatively, Hydrocorn is smaller, irregular in shape, and tends to settle into a more compact substrate. Hydroton is pH neutral. Whereas, Hydrocorn comes with an initial pH of anywhere in the range of 8 – 10. You need to soak with an acid solution for 4-5 days to lower the pH.
Hydroton vs Rockwool
Rockwool has more water retention capability and is considered great for seed starting. Unlike Hydroton, Rockwool is not pH neutral. They come with a high pH and need to be soaked in water before using. They are also not considered eco-friendly. Rockwool is also not recommended to use in aquaponics as it can cause irritation to fish or they can consume the fiberglass.
Hydroton vs Perlite
Perlite is relatively inexpensive and lighter in weight as compared to Hydroton. Perlite is not recommended for an ebb and flow system as it will wash away too easily during flooding. both are made to hold water and have a certain amount of water wicking ability. Although perlite has more cracks and crevices, Hydroton stays moist longer because of its higher absorption ability.
Buying Tips: Where & How to Buy
You should be able to get the clay pebbles at a gardening center, garden shop, places where you can buy large shrubs, bushes, and even tree’s.
Check Before buying: It can be any kind of rock really, just do a vinegar test. if you put a handful of the rock in a glass of vinegar and they bubble, then it has too much limestone and you shouldn’t buy it.
GROW!T Clay Pebbles are available on Amazon in 10, 25, 40-liter bags. They are less likely to break and cause system issues. They are pre-washed.
Leca Clay Grow Media has uniform pebbles in a 2 lbs bag with mostly five-star reviews.
Have any question? Feel free to ask in the comments. You can share your own experiences using these little red pebbles, that may add value to information and knowledge of others. & if you have any friends who want to know more, please share this article with them. Thanks for reading!