re: Slow Flow UGF

>However, I can think of 2 drawbacks of using a slow flow UGF (as described
>1.      all substrate MAY become aerobic.
>2.      soil/loam/vermiculite/whatever substrate cannot be used
>because it has a tendency to cloud the water.

I have what could be considered a slow substrate flow system in both of my
tanks and would have to disagree.  In both cases, flow is basically negligable,
and can be measured in drops per minute.  This isn't enough flow to upset much
of anything or to cause the substrate to be completely aerobic.  It does
promote substrate mixing, with can assist in dispersing sulfate accumulations.

I have a sand/vermiculite substrate in each of my tanks and find the
vermiculite to very good about leaving the water unclouded, even when I pull up
a plant.  Yes, I do get a small eruption of vermiculite flakes, but they settle
back out within a few minutes.  If given the time, they will either settle into
my sand, or they will eventually settle out in my settling tank.

David W. Webb
Enterprise Computing Provisioning
Texas Instruments Inc. Dallas, TX USA
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