[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re Osmocote evaluation


To make clay balls for your substrate, you start with dry, powdered clay,
such as might be sold in bulk to make pottery items. You could check the
yellow pages (or the Italian equivalent) to find "pottery supplies" in your
local area - pottery making is a common enough hobby that you should be able
to locate a local supplier.

What you want is a "terra cotta" clay - the red-brown color is usually
caused by Iron in the clay body. You don't want anything that contains
plascticizers or other materials - 100% natural clay is what you need.

If you can't find it, check with a Hydroponics shop for a product called
"PyroClay" or a suitable alternative. I believe that someone mentioned a
similar product on the APD a few weeks ago, also dry powdered clay.

The natural clay, when ground up, is like flour - very fine. Place a cup or
two in a bowl and slowly add water, mixing until you  get a stiff "mud"
which holds together - you want it on the dry side rather than "sloppy".
Take a quantity about the size of a "marble" and roll it together in your
hands. Using either a pencil or your finger, make a hole or depression in
the clay ball, pour in some OSMOCOTE (not too much) and then close over the
hole. Roll the ball a bit between your palms to ensure that the OSMOCOTE is
entirely inside the clay ball.

Set the finished balls aside to dry - you can bake them in a moderate oven
to hasten the process - you merely want to drive off the water. Once they
are dry, you can gently insert them into the substrate of your tank - they
will hold together long enough to get them in but gradually soften as they
absorb water and the nutrients will leach out of the OSMOCOTE. Clays have a
very high CEC and a lot of the nutrient ions will bebome "attached" to the
clay particles and held there until they can be absorbed by plant roots.

Just DON"T go overboard with the OSMOCOTE.

There is a APD list member (sorry, I can't remember his name) who sells a
small device which speeds up the process - his company's name is "Plant
Guild"  (http://www.familychest.com/plantguild/index.html). The device lets
you make clay "pellets" as opposed to "balls" and you would use powered
fertilizer. But it works very well and I use mine all the time - it also
allows you to insert the pellets safely into the substrate with minimal

Steve Pushak has some great information about clay on his web site -

James Purchase

Please note new e-mail address: jppurchase at rogers_com