Re: Bioballs, wheels, a lot of hooey about a lot of gooey?

["S. Hieber" <shieber at yahoo_com>]

A good case has been offered for bioballs as the preferred media in a
biofilter -- at least in a "trickle filter" (still rather a silly name
if you look at how they work -- 600 gph is a trickle?) where water
passes through the media as an oxygen rich film.

Bioball makers usually quote surface area per gallon, which might be
good if it's a high ratio (lot's of surface) or bad, clogs too easily. 
What actually matters, they rarely quote, which is how well it performs
at it's intended prupose.

Rotating media biological filters are used on moderately large systems
(bigger than aquaia, smaller than urban sewage plants) where the major
problems, maintaining rotation and "clean" media, can be addressed
affordably -- someone has to pay attention and correct stopped "wheels"
and clean them periodically.  Both of these things greatly affect the
effectiveness of the filters.  But for size verus biological activity,
they can't easily be beat.  For large sewage plants, they tend to be
disfavored due to economies of scale that favor other methods --
aerosol over large tanks.  

Biowheels, Marineland's small retail/hobbyinst, application of the
rotating membrane biofilters technology, purports to overcome the
problems of the larger versions:  with the Biowheels, the rate of
rotation is relatively insignificant at high water flow rates, based on
Marineland's numbers -- and for however much they do "clog" up, they
only do so up to a point and then can run for years without loading up
with more material -- I suppose they slough material.

*But do they maintain much surface area?*  Or to put it another way, do
they work?  

I've seen successful aquariums using "trickle" bioballs, Biowheels,
external canister filters, internal canister filters --- a person seems
to have great latitude when it comes to biofiltering a planted tank. 
[I recall Karen Randall once saying in answer to the question, "what
kind of filter should I use?" "what have you got?" -- my apologies to
Karen if my recollection is wrong.]

Does anyone have any hard data on how the various versions of
biofilters perform, how much biofiletering they actually accomplish?

If Biowheels perform, even if much less effectively than a sump and
bioballs, they are a heck of a lot simpler and that might be worth
someting to some folks.  Much of what I read about Trickles is how
owner finally overcame the problem of lossing the siphon, quieting the
noise, balancing the flow, saving the motor from burnout if there was a
temporary power outage.  OTOH, all of these are conquerable problems. 
Still, trickles seem to be rather complicated and finicky devices.

Sumps have advantages, and some folks have them on (well, under) their
tanks for no other purpose than to put the heaters and CO2 reactor
there and out of the aquarium.

I'm not claiming to have mastered filtering on my own tanks.  And I am
not advocating any one method.  I've bought, used, made or modified,
some versions of just about most filters.  And they all have some good
and bad points.  I'm just trying to make sense out the various info
available on filter media.  Why do plasctic balls that can be
manufactured by the thousands for what must be as high as pennies each
sell for dozens of dollars per gallon?  Or to put it more correctly,
why is the demand for them that high when shotgun wadding,
easter-basket mesh, scouring pads, shredded coffee can lids, and even
Biowheels have been applied successfully.  For comparison, considerm, a
Dupla transformer (for its heating cables) is very expensive but it's a
very good transformer and good transformers cost a lot to make (not
Dupla dollars, but still they are expensive).  But those plastic balls
are, well, there just plastic balls!  They really are!

Ehfisubstrat and other sintered products (often) not cheaper than
bioballs, and might not be all the useful even in a cansister filter.  

Methinks all the expensive media might be unnecessary.

Scott H.

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