Recommended sizes of power filters.

I stopped by the local Petco tonight. They're expanding their aquatics
department and had display samples of many types of power filters with charts
of the stats and manufacturers recommendations for each type of filter. I
took some notes as this issue came up a couple of days ago.

Here's the data:

Manufacturer gallons per hour tank size (gallons)

Penguin
100 20
150 30
200 50
350 75

Whisper
90 10
105 20
145 30
210 40
330 60

Cascade
80 10
100 20
150 30
200 50
300 100

AquaClear
100 20
150 30
200 50
300 70
500 110


So, with the exception of the filters for ten gallon tanks, the general idea
is that turning over the tank volume 4 or 5 times an hour is the usual
recommendation.

This sounds about right to me. Would biological filtration be that much
better with a higher turnover? I suspect not. A higher turnover might make a
difference to mechanical filtration, but I doubt anyone has that much gunk to
filter out.

Conclusion: Anyone who recommends larger powerfilters than what the
manufacturer recommends is needlessly upselling. So in this case, the filter
makers are the good guys. Of course, they do have their little scam going.
They suggest changing out media every month. I know that water quality drops
with new media, even though there's fresh carbon. That's how they get you.
Kinda like inkjet printers.

-E