At a recent Koi club meeting we had a speaker who was a vendor for a
brand of calcium montmorillonite, i.e.: "Koi Clay" (but not that
particular brand. The claimed virtues are impressive and include
detoxification and neutralizing bacteria in the pond water.

It was said that as the clay will neutralize both bad bacteria and
good bacteria, not to add it at the same time as you add LymnoZyme,
a popular "good" bacteria that many Koi keepers use. The advice is
to add the LymnoZyme a few days apart from adding the clay.
Okay, this makes sense. But I did not hear a satisfactory
answer to why calcium montmorillonite wouldn't damage the
bacteria in a biofilter.

Any thoughts on this?

Steve J. Noll | Ventura California (zone 10)
| Glass Block Pond http://www.kissingfrogs.tv