[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Diy above tank cannister trickle filter.

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 ...

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