One of the first decisions you will have to make before
planting your new crop is the choice of a growing medium (or substrate). As you
may have read in our hydroponics growing medium page, growing media may be used
to sprout seeds (or cuttings) before transplanting, and it is mostly used to
give hydroponic plants an anchor for its roots after transplanting to into a
hydroponics system. Not only does the
grow media acts to support the plant, but it also provides a way to oxygenate
and hydrate the root zone. Clay pebbles are quite possibly the best grow medium
for hydroponics because it fits all the criteria you want in an effective grow
media.
Lightweight Expanded Clay Aggregate (LECA) – often referred to Hydroton or clay pebbles
– consist of balls of clay that has
been super-heated (in a rotary kiln) from anywhere between 1100 to over 2000°
F. This process causes popping, which creates the pebbles’ characteristic
pores. These pores, in addition to the spaces between pebbles, make Hydroton a
light and airy growing medium that provides water, air, and drainage. They are
pH-neutral, non-degradable, and do not add any additional nutrients or substances
into the nutrient solution within a hydroponic system reservoir. Clay pebbles
are also reusable, which makes the initial cost easier to stomach. Because of
their advantageous properties, clay pebbles are very popular with both
hydroponics. In fact, clay pebbles are also the most popular aquaponics grow
media as well.
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.
While grow stones are smoother than some media, they are not
so smooth as to discourage colonization by microbes. As you may know from
biological surface area (BSA) resources, BSA provides habitat for the microbes
which make nutrients from organic sources like fish feed available to plants.
Less BSA means fewer microbes, which means a less responsive and less stable
system. Though possessing less BSA than some media, this grow medium still
offers high BSA.