Submerged vs open air bio-media?

Submerged vs open air bio-media?

While this probably has little to do with aquariums and more to do with ponds, it is and interesting question. In researching filters for some of my new projects I have been intrigued by the talk of open air bio-media being vastly more efficient then submerged media. This is in the context of being used in trickle towers and Bakki Shower type pond filters. I guess the idea is that the bio-media being open to the air greatly increases the oxygen available to the nitrifying bacteria. Not to mention the oxygenating of the water as it trickles/falls through the filter.

So if anyone has any thoughts on this I would love to hear them.

Steve

Thanks Steve for mentioning this as now I will have to look these up. They sound like a great filter for pond or tank.

I may have a hard time to make a Bakki filter for a smaller tank. I just read up on them and I think Steve with your skills you could make a DIY version. With ceramic bio media or lava rock the trick might be getting the flow rate just right with your pump.

Going to read up on this some more and probably make up something to try.

Steve

I know the bio media in my aquaclear filters, and the fluval filters are set up to be exposed to the air for this reason, and seem to work pretty darn slick. I don't see why it wouldn't be better for a pond set up too.

Here's my two cents, which with the current exchange rate is worth one cent... It really depends on the oxgenation level of the water/tank. If oxygen levels are high, the bacteria could care less about open air or not. Their rate of nitrogen fixation is usually limited by oxygen levels in water so if there was a large depletion of O2 which I think can happen in certain circumstances (i.e. planted tank), then yes the open air concept would help. That being said, if you have sufficient surface area its not going to matter... there will just be more bacteria to do the job, albeit less efficiently.

The thing to consider is that the bacteria we like in our tanks don't do dry well (i.e. they die) and they need a constant supply of N, otherwise they die. So a totally open air system might be at risk of colony die off in power outage situations.

Anywho, just my semi-educated ramblings. I do have a BSc in biochemistry, but that seems like an eternity ago and I've meandered through very different careers.

I have read that bio filters can be with out water for short periods like power outs as long as it is only up to 6 hrs. and the media stays moist.