Page 13 - TBAS-October-2020

TBAS October 2020 .................... -13-
oxygen.
Therefore, this filter responds very quickly to an increase in ammonia loading.
When more fish are added to the system, the ammonia load naturally goes up. To
compensate, simply increase the flow rate of the main water circulating pump to
push water through the system more rapidly.
This increased flow rate will increase the efficiency of nitrification when the
ammonia load increases.
Original design dilemmas The first types of trickle filters offered to the
fishkeeping market used a stationary perforated pipe that water flowed through
and dripped from.
While this design was simple and reliable, it suffered from uneven distribution
of the incoming water. This uneven distribution repeated itself throughout, meaning
that the full potential of the filter went underutilized.
There were also problem backups at the drip holes within the stationary
perforated pipe caused by particulate matter.
Another design for increased air flow meant open-sided trays, but this
increased evaporation and led to cooled circulating water and higher levels of
dissolved salts.
An alternative to drip tray designs was the rotating spray bar. These are
gear-driven rotating bars similar to those used in water treatment plants.
Since the exiting water jet produes a very low torque on the spray bar, the
bearing used must be as frictionless as possible. Early metallic bearings were
unreliable, as salt deposits got in the way and caused friction.
Today, however, manufacturers have discovered high-quality teflon bearings
which do not corrode and are slick to marine water salt and even more reliable in
fresh water.
To cut back on evaporation, filter makers have enclosed the rotating spray
bar’s area of operation. For enhanced oxygen, an air stone is placed below the
filter media.

Foam Fractionation
Probably the biggest breakthrough in water treatment and filtration these
past few years has been the process known as foam fractionation.
This process has been incorrectly referred to as protein skimming. I say
incorrect because actual protein skimming takes place at the surface of an aquarium,
where the water is removed at the surface by an overflow.
Foam fractionation not only removes proteins, but also removes particulate
organic carbon by entrapment in the foam. Thus, it is an auxiliary mechanical
filtration technique which includes removal of microorganisms In suspension.
The biggest “new” thrust in foam fractionation has been the addition

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