Leca clay/Hydroton is a popular medium because it has more benefits and a few downsides. LECA or Hydroton is a standard medium used in Aquaponics, Hydroponics, and Aeroponics. We’ll discuss in detail about this medium in this post. From Introduction to pros/cons and do’s/donts.
What is Leca Clay?
Hydrotron is a favorite choice of small producers using media bed or Dutch bucket techniques because of features like lightweight, easy to transplant & harvest, and easy on the hands.
Clay pebbles can be used in both hydroponic and aquaponic systems.
How is it made?
Leca/Hydroton is a processed ceramic lightweight aggregate produced by expanding selected clays in a rotary kiln fired to a temperature of approximately 1200°C. This process expands the material 4 to 5 times its original volume creating ceramic pellets with 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
Hydroculture: Their neutral pH and excellent capillary action qualities make them a great hydroponic/Aquaponics medium. Typically used in flood & drain or ebb & flow growing systems. Preferred by horticulturalists for hydroculture, this product offers many advantages when compared to soil. The medium is clean, odor-free, reusable, and provides excellent aeration.
Leca is also a useful additive to Coco Medium and Soil when growing in Pot Culture and also anywhere where extra drainage is needed. Also Used in drainage layers in flower pots, roof gardens, for trees in an urban setting and sports grounds.
Substratum cultivation in professional horticulture and the cultivation of decorative plants: This highly porous growing medium is used to fill plant baskets and container gardens and provides good physical support for roots.
LECA prevents rotting, excess acidity, and soil pests. Great for aeroponic, NFT, and GHE water farm/Dutchpot systems.
How to Use Clay Pebbles: Do’s & Don’t
The Flood & drain and ebb & flow are the usually recommended methods for using these clay pebbles. Here are some do’s and dont’s to keep in mind while working with them. When using for hydroculture (Aquaponics/ Hydroponics/ Aeroponics):
- If you’re using new hydroton, rinse it once with clean lukewarm water before using; it can be dusty and cause clogging problems in mesh filters or drippers.
- Sometimes it floats! Nothing to worry here! When you buy a new one, some of the clay pebbles will float. It is normal till they soak up some water. These need to be held under water and made to fill up. Soak the pebbles for at least six hours or, even better, up to 24 hours. You can put something heavy on top to hold them down. The air should escape. Yes, the medium will be heavier but your plants won’t have to work hard to get to the water they so desperately crave.
- Remove the dirt as far as possible from the plant
- Spread a 3-4 cm thick layer of pebbles in the hydroculture pot
- Place the plant in the pot and top up with until there is a water margin of 2cm. While topping up move the plant gently up and down so that the clay is all around the roots.
- 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.
- Use clay pebbles as Seed starter: You can crush the medium to increase saturation or you can keep them whole, use small net pots, and cover the seed with a couple of pebbles. Misters set to bursts lasting four to 10 seconds every two or three hours will bring on germination. Just make sure you have soaked the pebbles beforehand. If you don’t have misters, manual feeding will work fine, too, as long as you don’t let the pebbles dry out.
- Don’t reuse the pebbles without rinsing, soaking, or sterilizing with isopropyl alcohol or peroxide. Taking the time to do it right will save headaches later.
- Never let the pebbles dry out. Ever. Period.
- Don’t use a regular pot unless you have a dedicated water source. Using regular pots can sometimes lead to algae and draining issues.
- Don’t use the pebbles as a substitute for soil outdoors. You can certainly use them in conjunction with soil but not as a replacement in your outside garden.
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!