Denitrification, Will this work?

[hortoholic]

Hey guts, its been a while since I last posted but I was wandering if it would be possible to build a denitrifier in a more simple way?

Basically, take a plastic bottle (20oz or so). (By the way, would there be any fish safe plastic bottles?) Then, Drill a few holes (on the top and bottom) and fill it with gravel and submerge.

The idea is that water will saturate the gravel and some of the beneficial bacteria will be on the top and as you go deeper the oxygen gets scarce and thus the 3rd type bacteria can survive. It will be slow. But can it work? Or can you improve on it?

I appreciate your replies.

hortoholic

 

[adeebm]

I think the space between the gravel might be too much for a deoxygenated area. However, if live rock can work in SW, then why not in FW? As long as it gets seeded with the right bacteria. Maybe you could build a chamber with live rock.

--Adeeb

 

[BigJim]

People do this for saltwater tanks. It's called a deep sand bed. I haven't seen anyone attempt it for fresh water, but it might work. It's risky at best.

 

[hortoholic]

BigJim, I have gravel so that is what I am trying to replicate. But what risks will I incur? I have good aeration and oxygenation/circulation. Would I need holes on the bottom or just a deep bed of gravel? as for a "chamber", would glass be suitable?

 

[BigJim]

I haven't tried anything like this personally. Deep sand bed denitrification seems to fail spectacularly when it goes bad. Between the hydrogen sulfide gas and the nitrates, I've heard of it nuking tanks.

Aeration and circulation won't help the nitrate eating bacteria. They're anaerobic bacteria, meaning they thrive in oxygen-depleted environments. I'm not sure you could pull it off with gravel. If you're going to run this remotely, get some sand. It's cheap. Glass should be fine.

I think if I were going to try it, I'd set the reactor up separate from my tank before attaching it. Seed it with ammonia, much like a fishless cycle and build the bacteria before putting the tank at risk.

Fast-growing stem plants are wonderful nitrate eaters.