The way I understand it, whatever media you're using for your mechanical
filtration will be performing your biofiltering anyways. Unless of course
deliberately kill the bacterial colonies when you clean the filters on a
fairly regular basis.




"Dave Millman" wrote in message
...
I've been experimenting with different methods of CO2 injection. About
120 days ago, I began using a cannister filter. I took all the standard
precautions to preserve the biofiltration: preseeded it with mulm and
old filter material, ran the old and new filters concurrently, etc.

But I wasn't satisfied with the mechanical filtration. Then I remembered
the occasional advice on this list that biofiltration is just not
necessary in a plant tank. So over a week, I removed all the old media.
The tank has had no external biofiltration for 90 days at this point.
Yes, I know that any mulm sucked into the mechanical filter performs
biofiltration, but I am doing nothing to preserve the bacteria colonies
in the filter. Instead I am loading it for mechanical filtration and
completely changing media whenever necessary.

I suppose I should have tested ammonia and nitrite levels, but I haven't
tested those in a year and the reagents are probably bad anyway. But the
plants are thriving, and fish seem happy (that could be due to the fact
that half their diet is now live Grindle worms, but that's another
story.)

My question:

Given that biofiltration is now exclusively performed by plants and
in-tank bacteria, what should I be careful of? I try not to disturb the
gravel unnecessarily, and scrape only the front glass. The tank is
heavily planted, with a nice carpet of dwarf hairgrass filling in. I
haven't vacuumed in 14 months.

Thanks!