Re: Diy above tank cannister trickle filter.

[Damian Barton and Jenine Plunkett <jpordb at ozemail_com.au>]

Damian Barton wrote:
>
> I just wanted to let you know about my 'new' filtration
> setup that replaced my conventional diy trickle filter
> - -overflow, bio-tower and sump-setup.> ...
> The barrel is completely airtight so there is
> no Co2 loss or water evaporation ...


Damian,
If the system is air-tight prior to the output, then where will
your bacteria get the oxygen necessary for nitrification?  I
have a large air pump injecting air into my media tower.  Just
wondering if I missed something, here ...

-- Keith
From what I have read, the intense aeration provided by a trickle filter
helps keep the water aerated, but it is not absolutely required. In an
airtight trickle filter, the oxygen for nitrification must come from the
water. In a planted tank, or a very well aerated tank, then O2 levels
dissolved in the water are high enough that it should not make a
significant impact, and a sealed trickle filter should work almost, or
as well as, an aerated trickle filter. In fact, when CO2 is being added,
O2 saturation can increase from 80-90% to 110-120%, so the greatly
decreased CO2 loss causes dissolved O2 levels to increase, providing
more than enough oxygen for nitrification.
Most filters only rely on dissolved oxygen anyway. Underwater filters
work perfectly well.
Andrew McLeod
thefish at theabyssalplain_freeserve.co.uk

Hi Andrew,
that's the thought I had about my tank and filter
setup- that with Co2 and plants etc the water should
have a certain level of oxygen, although I think you've
provided a more detailed and accurate explanation.

Regards
Damian.