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Re: Confused about biofiltration

Scott H. wrote:

> The
> discussion had been about what biomedia might be equivalents, or better
> or worse than bioballs.  Which all begs the question that Rachel asked.

Rachel Sandage said:
> I have been reading the discussion about bioballs with some interest,
> because I think that after 2 years of fishkeeping I understand the
> whole 
> subject less than I did when I started. I understand the nitrogen
> cycle - 
> NH3->NO2->NO3, right? What I don't understand is why bioballs are
> useful in 
> a planted tank. For one thing, doesn't the surface area of all the
> plants 
> act as a place for bacteria to grow? There is whole lot of plant-leaf
> surface area in the tank.

The surface area of the leaves is relatively poor bacterial
growth location, in part because the water flow is not
nearly as good there as in a dedicated filter.  Again
reference Spotte's work - which some apparently seem to feel
has no relevance.

Rachel Sandage also said:

> For another thing it seems to me that the
> plants 
> would be able to handle - would in fact enjoy - any ammonia spike
> which 
> might happen as a result of adding more fish, overfeeding, or killing
> off 
> the biofilter using medications. At least that seems to be the case
> in my 
> own tank.

But is the tank of every APDer comparable to Rachel's?  I
have no way of knowing.  But I do know that my tanks are not
the typical tanks profiled on this list - mine are planted
fish tanks, not plant tanks with fish maintenance crews.  I
have no desire to subject my fish to any detectable ammonia
when I need not.  The plants are there for beauty and as a
secure and attractive environment for the fish.  In those
few tanks of mine requiring nitrogen supplement, I certainly
do not add ammonia (which the plants would doubtless utilize
more efficiently than the nitrate I do add) because I don't
want to damage the fish and inverts.

In the same digest, Tom Barr mentioned Discus, but the same
would apply to any fish which by their nature are messy
eaters yet demanding of water quality.

Rachel Sandage finally said:

> So what am I missing? Why use bioballs (or their equivalent) in
> planted 
> tanks?

Because not all tanks belong to all subscribers here are
"plant purist" tanks, but are operated as beautiful and
healthy environments for fish.  If there is no food for the
bacterial colonies, they will not exist, and I don't believe
anyone here will hold that bioballs (or their equivalents)
alone are intrinsically harmful.  If they maintain
functional colonies, then there is a need or function for
them, and they are serving a beneficial purpose in
minimizing fish exposure to toxic metabolites.

Does that answer the question?