biofiltration in a planted tank

[Roger Miller <rgrmill at rt66_com>]

Rachel wrote:

> 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.

There is, and it is biologically active in a lot of ways.  Most of us try to 
avoid having a big biofilm buildup in the tank, and our surface-feeding fish 
are pretty good at preventing buildup.  Even without a big or even visible 
buildup there is still a substantial bacterial activity on all the surfaces, 
plus the activity of the plants themselves.

Just remember that you have to keep good circulation.

> 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.

Well, the plants are fine with it.  The fish may not be real keen on it.  
Despite that, the fish and shrimps in my tanks happily breed and live on to 
ripe old fish ages.

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

They don't have much purpose in a planted tank except under two conditions 
that I can think of.

They're great for the person that wants to keep more fish in the tank then 
the tank and plants are otherwise capable of handling.  Personally I've never 
found an overpopulated tank to be very attractive.  I also doubt that 
overpopulation is good for the fish in the long run.  But then, attractive 
and good in the long run are only two considerations.  I suppose there are 
more.

They're also great for gadgeteers.  A hobby is a way to occupy time with 
interesting tasks.  To some people that means playing with gadgets.  Fancy 
filters are great gadgets.

You don't have to worry about using bioballs (or any other sort of biofilter 
medium) unless you really want to.


Roger Miller