Quote Originally Posted by BluFin
I am wondering what benefit there is, if any in using baked clay balls over gravel or other media. Basically as I understand it, the media supports the plants, gives a surface for sludge to adhere to, and drains to allow oxygen exchange.
Hi BluFin, Your understanding is pretty much spot on.

Folks like the clay balls..as I understand for a few reasons...

One, they are very light in weight. The supports for the system don't have to be 'heavy duty'.

Two, it's very easy to remove the plants when done growing, or to re-locate...or I even heard of folks pulling the plants out to spray off bugs and then sticking them back in.

Third, normally, there are no issues with their effect on the water's PH.

On the negative side...
-They co$t a lot....
-When you have taller plants, the clay balls just don't support as well as river rocks.

If I remember, the company that made Hydroton....stopped production, because they couldn't find a good continuing source, of the type of clay that they wanted.
What type of clay...sorry...I don't know.