Have any of you tried this product in your ponds? It was recommended to
me by a friend who has Koi.

(Snip)
Calcium Montmorillonite clay (AKA: Bentonite Clay)
Terra Pond=99 is a complete nutrient source
that clarifies and detoxifies pond water,
Improves fish color and conformation,
Improves fish immune system and is used
For Goldfish and Koi.

TerraPond is an absolutely pure form of Calcium Montmorillonite clay. It
contains color-enhancing nutrients for your fish and plants and also
removes impurities that result in clarifying the water until it
sparkles.
TerraPond is a very fine, pure, edible clay and it will stay suspended
in your water while doing its work.

Many first-time users are often concerned when their water doesn't clear
in a short period of time. Please do not be alarmed. Even if you
accidentally apply a dosage that exceeds our recommended amount, you can
never harm or overdose your fish with this 100% natural product.

HOW IT WORKS:
The magnetic attraction immediately begins when negatively charged
TerraPond is introduced into your pond water and begins the
micro-encapsulation process. This electrical ion exchange process is
also referred to as "flocculation."
As a result, the electrically bonded particles are larger in size and
weight. In Koi ponds, this increased mass then becomes filterable in
most bio filter systems


We suggest that you start with a conservative dose if your pond water is
already at or close to an acceptable level of clarity. TerraPond's
colloidal suspension properties allow it to continue bonding with
impurities, carrying them safely into your filter. It also allows more
nutrients to get into your fish's systems. Since the best koi are raised
and live in mud ponds, your fish will thank you for their mud bath that
improves conformation, coloration, health, and vitality.