Hydroton is an interesting manmade product offering a lot of advantages to hydroponic growers.
Hydroton is a form of LECA, which stands for Lightweight Expanded Clay Aggregate. LECA is a porous, lightweight, manmade clay material that resembles lava rock in its structure. But instead of lava rock's irregular size, it is formed into regularly sized round balls. Different ball diameters are available to correspond with different crop needs, but typical sizes are 3/8" and 5/8" diameters.
This material is a relative newcomer on the hydroponics scene, but it has received good reviews and is in regular use with both hobbyist and commercial growers.
growing medium offers growers a number of advantages. It is
chemically inert so it won't affect the pH. It is easy to handle given the
round shape and light weight, yet provides sufficient mass to anchor the
heaviest production trellises. It can be dusty at first but it is very
easy to wash down, and it is not dusty after that point. It has some
reusability, since the round size is amenable to cleaning and the surface pore
spaces can be cleansed and/or sterilized with various treatments. I don't know
how many cleaning cycles it can go through but it's better than rockwool in
It does have a few disadvantages. First, it is one of the more expensive growing media. That might work out OK since it can be reused at least a few times, so that cost amortizes out over several growing seasons. Yet startup acquisition will be a hit to the pocketbook. Secondly, it can be challenging to start small seeds in the clay balls, since the large spaces allow small seeds to fall down to the bottom of the planting bed. Third, it is not as easily available as other growing media, although online retailers are plentiful. More and more gardening and hydroponic retailers will bring it in as a special order but they may not yet stock it regularly.
LECA growing media products have
recently gained more and more favor amongst hydroponic and aquaponic growers as
a cost effective option with good performance. Yet they are still relatively
unknown outside those circles. If you have a local hardware store or home
improvement store that does a lot of business with commercial growers,
landscapers or nurseries, you may start your search there. But don't be
surprised if they've never heard of it. They may or may not be able to special
order those products for you. Even commerical nursery and greenhouse equipment
dealers may or may not carry it.
A second option is to visit with specialty hydroponics suppliers in your area. Anyone in the business of providing hydroponics supplies and hydroponics equipment should know about hydroton.
A third option is to check with online hydroponic retailers. These by far are the most likely to not only carry this type of growing media, but in a variety of sizes. These retailers are often very competitive with each other for pricing. Here is an example of one online retailer's hydroton product line.