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Triangle Filter


  1. Mechanical Filtration
    by "Roger S. Miller" <rgrmill/> (Thu, 13 Apr 2000)
  2. Mechanical Filtration
    by "Roger S. Miller" <rgrmill/> (Fri, 14 Apr 2000)

Mechanical Filtration

by "Roger S. Miller" <rgrmill/>
Date: Thu, 13 Apr 2000

On Thu, 13 Apr 2000, Ivo Busko wrote:

> > are problems.  A self-cleaning mechanical filter like the (patented)
> > triangle filter might also be good for aquarium use.

> Would you care to elaborate what is this triangle filter ?

I've only read descriptions of the triangle filter.  The key part of the
filter is a sloping, fine-mesh screen.  As I understand it, unfiltered
water is pumped onto the high end of the sloping screen from where it can
either fall through the screen or flow across the screen. Water that falls
through the screen is filtered by the screen and is collected from below
the screen and pumped back for reuse.  Water that flows across the screen
carries detritus off the screen; that water and the detritus are collected
at the foot of the screen and pumped away.

The triangle filter is self-cleaning because the detritus is constantly
washed off by the water flowing across the screen.  I imagine that slime
builds up on the screen and the screen would have to be scrubbed
frequently to keep it working right.

The filter is built and sold for fish farms that recirculate some of their
water supply.  I only imagine that it might be used in aquariums.  The
flow from across the screen (carrying the detritus) would be dumped to a
sediment trap and clear water would be skimmed off the top of the trap and
returned to the aquarium.  The filter would probably need to be installed
beside or above the tank so that the return flows will work by gravity
flow.  Alternatively, the return flows might be dropped to a sump and
pumped back to the tank

A centrifugal separator would work in much the same kind of setup.  In the
case of the separator the return line from the sediment trap could be
connected to the main return line through a valve.  The assembly would be
simpler than the triangle filter assembly and it could be placed below the
tank without using any sump other than the sediment trap itself.  Very
little maintenance would be needed.  On the down side, most aquarium
detritus is pretty light, so centrifugal separators can't be expected to
work real well.

In any case, the sediment trap would have to be cleaned now and then.

Roger Miller

Mechanical Filtration

by "Roger S. Miller" <rgrmill/>
Date: Fri, 14 Apr 2000

On Fri, 14 Apr 2000, Ivo Busko wrote:

> Thanks, Roger, for the explanation on the triangle filter. Sounds
> interesting, but one thing is not clear. Is the screen fully submerged ?
> If not, the filter's CO2 degassing power ought to be significant.

The industrial-scale filters are probably open-air.  Fish farms have far
more interest in getting CO2 out then they do in keeping it in.  In their
case the aeration that comes along with the filter would be a plus.  The
same thing might be said for fish-only tanks, or tanks without added CO2.

This goes beyond my original imaginings, but for most plant tanks you
probably would want to house the filter inside an enclosure.  I doubt
that would create any more outgassing than would a trickle filter.

Roger Miller

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