If it happened that night, or by the next morning, then it was almost
certainly the nicotine that killed the fish. One almost never hears of a
home aquarium going down after the biofilter is removed or offline for an
evening or even a day.
> P.S. Sorry, no one has explained the function of a Fluidized bed filter.
> Please, can anyone do this? You can use private mail.
Water is pumped into the bottom of a sand bed. The sand is colonized
with bacteria. The amount of water pumped into the system is sufficient
to keep the sand "fluidized" and moving freely. This prevents dead spots
from forming in the filter. All of the (enormous) surface area of the
sand is available for bacterial growth. The active area is greater than
the same volume of any other media. DLS might seem to have as much or more
area, but it rapidly plugs with a bacterial mat. The bacteria are also
kept in a thin film stage (because of the mechanical action in the sand)
which keeps then in a highly productive stage where they are getting good
water flow and nutrient exchange to all the bacterial. The action of the
filter also keeps the thickness of the boundary layer around the sand
thin. (Water flow tends to go to zero around any surface. Maximizing
productivity of bacteria, algae, plants, corals often involves keeping
that boundary layer as thin as possible.)
So they are kick ass nitrifying filters. But they are also total overkill
for home aquaria, prone to catastrophic failure, and pretty much
diametrically opposed to my model of how aquaria should be. I tend to
like "natural" types of systems much more.
Craig