The Truth About Bio-Balls

[Reefscape]

I shall certainly stand by the statement that wet/dry filters should not be used on a marine system. We need to have the anaerobic area, and having small, golf ball sized live rock rubble chunks in the sump WILL provide this for us.

Just my opinion of course

Niko

 

[Gangstafish]

No matter how much live rock you have you still need a good protein skimmer. The Berlin system that everyone is talking about consists of live rock and a good protein skimmer. No one has mentioned a protein skimmer.

 

[mrtuskfish]

Mechanical filtration should be used before anything that can be effected by gunk build-up. Bio-balls, any type of media bag (carbon, chemi-pure, phosphate remover, etc, etc,) UV sterilizers, even some skimmers that clog easily.

 

[New Reefer]

... We need to have the anaerobic area, and having small, golf ball sized live rock rubble chunks in the sump WILL provide this for us.

... The minimum size of live rock capable of sustaining denitrifying anoxic bacteria would depend on the porosity of the rock, but is very rarely smaller than a large fist size.

OK, we seem to disagree on the smallest size rubble to use what's important is that we both agree that there is a minimum size limit...

Although even small pieces of rock would have *some* anoxic areas, it stands to reason that larger rocks (of the same density/porosity) would have larger anoxic interiors, thus having larger "substrate" for the growth of more nitrate reducing bacteria. Of course, on the bottom of a very slow moving area of the tank/sump the O2 level in the water surrounding the rubble would become anoxic as well, and the whole golfball size rock would become anoxic, but then one would not have much aerobic filtration in that piece of rubble.

Many years ago I experimented with adding an anoxic region filled with plastic hair curlers (cheap equivalent to bio balls...) below a wet/dry trickle filter, and this worked quite well in reducing nitrate. I later replaced the curlers with ceramic filter "noodles" called BioMax (distributed by Hagen) and this worked even better, keeping the nitrate level below 20ppm, even though each "noodle" was only slightly larger than a thumb nail. I later removed the trickle filter, increased the amount of large pieces of live rock, and added a deep live sand bed, and within a short period the nitrate level dropped to less than 1ppm.

Given the above, I still maintain that fist-size rock (or larger...) gives a better "balance" of aerobic and anoxic bacteria, thus allowing for OPTIMAL filtration - oh, and it does not matter if you have it in the tank or sump.

Just to clarify a final point: I'm not saying that small LR rubble is bad, only that it is not a very efficient nitrate reducing filter. Small pieces of LR rubble in the tank or sump provide the ideal breeding ground for many small critters who will assist overall filtration by eating detritus, and as an added bonus become food for your corals and fish, so by all means do add some rubble to your sump :grinyes:

 

[jojo22]

Just to clarify a final point: I'm not saying that small LR rubble is bad, only that it is not a very efficient nitrate reducing filter. Small pieces of LR rubble in the tank or sump provide the ideal breeding ground for many small critters who will assist overall filtration by eating detritus, and as an added bonus become food for your corals and fish, so by all means do add some rubble to your sump :grinyes:

But no matter how much nitrate reduction the LR rubble does it is still MORE than any bio-ball on the market thus making it a better choice.

 

[Nolapete]

I don't think any bio-balls were designed for denitrification, but only for nitrification as an aerobic bacteria host. Expecting it to do something than what it was designed for is ridiculous.

No matter what the media you use, there must be anaerobic conditions present for denitrification to take place. Denitrification is not a quick process. Developing an active anaerobic bacteria colony isn't going to happen overnight and will die off to some degree when aerobic conditions are introduced. It's kind of like deforestation. Their place to live is reduced.

For a scientific reference to anaerobic biodegradation see http://toxics.usgs.gov/definitions/anaerobic_biodegradation.html

To say bio-balls are bad is not entirely accurate. Poor maintenance of bio-balls is the real culprit. I suspect that is the same problem with crushed coral, but that's another topic altogether. If bio-balls are rinsed periodically with tank water when doing scheduled water changes, a pristine aerobic bacteria colony can be maintained without any of the "detrimental" effects. No pun intended.

I'd also enter that trickle-filters aren't all that bad either, but that they, like most equipment in the hobby, need to be improved and even evolve into something better.

 

[New Reefer]

But no matter how much nitrate reduction the LR rubble does it is still MORE than any bio-ball on the market thus making it a better choice.

I think you're missing the point...

Both the rock and the bio balls are merely substrates on which the bacteria live - you could just as well use plastic hair curlers (as I did years ago...) or even pieces of bricks - in a high flow oxygen rich environment (trickle filter) they will all be populated by aerobic bacteria, and none of them will reduce nitrogen. In anoxic (that is: oxygen poor, but NOT anaerobic) conditions ALL the substrates will be populated by nitrate reducing bacteria, so your LR rubble would not necessary be a better choice as such - you must still ensure that conditions are suitable for nitrate reduction to take place. That's why I suggested that larger pieces of LR would be "better" than smaller pieces, as they would have larger anoxic areas in their interiors, and thus be capable of housing more anoxic bacteria.

 

[ooja3k]

you can put live rock rubble in even the most aerobic areas of your tank, yet still have the anaerobic bacteria doing there job deep within the rock... there are no deep pores within bio-balls or hair curlers like there are within LRR...

granted, there are more of these anaerobic areas within a larger piece of LR then a smaller piece. but even this small anaerobic area within the pores of the small LRR, is bigger then the anaerobic area of a bio ball or hair curlers as they are made out of plastic...

does that make sense?

 

[New Reefer]

you can put live rock rubble in even the most aerobic areas of your tank, yet still have the anaerobic bacteria doing there job deep within the rock... there are no deep pores within bio-balls or hair curlers like there are within LRR...

Have you ever removed a piece of LR from the water and noticed the water draining out of the interior of the rock? Good quality live rock is VERY porous, and if a small piece of LR rubble is placed in strong flowing water (such as in most sumps) the interior just won't become anoxic enough for the nitrate reducing bacteria to live (multiply) in (in meaningful quantity), so the small piece of rubble will have just as little anoxic bacteria living inside it's "deep" pores as the bio balls or hair curlers will have living on their outer surface.

granted, there are more of these anaerobic areas within a larger piece of LR then a smaller piece. but even this small anaerobic area within the pores of the small LRR, is bigger then the anaerobic area of a bio ball or hair curlers as they are made out of plastic...

does that make sense?

No, not really...

Please understand the principle I'm trying to get across - it's irrelevant what the substrate is made of (rock or plastic...), the only important criteria needed for nitrate reduction are the size of the surface area and an optimally anoxic condition in the water and/or substrate (and of course a supply of food - nitrate). By the way, your referring to "anaerobic" bacteria is not really correct - our good nitrate "eating" bacteria needs some oxygen in the water. Proper anaerobic bacteria use sulpher instead of oxygen to "eat" the nitrate, and this results in the dreaded hydrogen sulphate black areas one ofter find deep inside really large pieces of LR (or sometimes in really deep sand beds).

 

[jojo22]

Please understand what we are saying. You seem to want to continue arguing something you clearly do not understand. even the seemingly solid parts of LR have pores in them. Please take a piece of rubble and crack it open, even after the water has stopped draining once you crack it open there will still be a good amount of moisture (water) left in the rock. There are MANY experienced reefers in this thread trying to explain something to you. If you are not open to others knowledge then what is the point of coming to a forum other than to argue?