There are also bio-balls that contain foam, ceramic or carbon, which go beyond the average golf-woofle ball variety sold at
lfs's.
Bio-balls are an effective solution, if properly maintained.
The problem (and the bad rep) appears to be because of lack of maintenance.
In the defense of those that use the bio-'media', the instructions do not say they should be properly cleansed, perferably replaced, every 6 months or so.
The 'or so' depends on your bio-load and additional cleansing support.
As with any filter 'media' beyond a biological filtration in a naturally maintained sense, they need to be cleaned or replaced in a regular fashion.
I've read many an article that states there is not a darn thing wrong with bio-balls (cause well, I researched it.. cause I got them as a gift and have to stick with them until such a time as sense warrents I replace them). Many people have used them for a long long time, doing regular maintenance and have been worry/problem free.
It's just like any ANY filtration system... be mindful of how it works and what the reprecussions are from not RTFM'ing..
Is live rock the more natural way? sure!
Is it preferable to the active hobbyist? yes...
Is it fallible? Only as fallible as anything else..
If you cannot take the time to do
pwc's or test regularly or bother to write down when your bio-balls are due for a good cleansing, then I don't see how live rock in place of the bio balls will make a big difference - assuming you arn't neglecting the other aspect of your system like a skimmer, good flow, clean up crew, good feeding habits, etc, etc.
Honestly, and here's a good rant, it's like saying a
UGF isn't an effective filtration system. That's a misnomer, because well...they work just fine if you take the time (and the setup with the
ugf is sound) to properly maintain your system.
Bottom line is that no matter the oppinion, an appropriate (for flow and bioload) system works..no matter what type it is.. _IF_ you are willing to do what it takes to keep the system properly maintained.
My 2 cents...take it as you will..
EDIT - heh...and no, they don't contain nitrates, they can collect them and continue to introduce them to your system through the cycling of your water through them. They are sterile plastic when you get them, they just gather bacteria while 'working'.
Stirring them up occasionally during the months to changing can help (but might also drop nitrate-ladden-stuff back into the water..)
Guess I shoulda answered the ? first before the lecture (and I'm hardly to the point I should be lecturing)..
And to further edit, and more get back to the question.. your bio-balls are probably aiding in mechanical filtration and aeration right now.
Rubble (
lr - true
lr with good bacteria, not dead rocks or uncured
lr (while those could help, they could also put the tank back into cycle)) properly placed would do the same thing.