Completing The Nitrogen Cycle Naturally

People talk about having a completely cycled tank. In my mind that means 0 ammonia 0 nitrite and here's where it gets tricky 0 nitrates, hence completing the cycle, going full circle. But in all my research we keep our nitrates low, but not gone with plants and water changes but to achieve the and maintain the BB that converts nitrate into nitrogen seems incredibly difficult if not impossible. I'm trying to do this naturally with bacteria not things like chemi-pure blue or purigen or chemicals or additives that claim to reduced or remove nitrates. In my research I've found one guy in particular that talks about this process by which we complete the cycle with anaerobic bacteria, (forgive me if I have labeled this bacteria wrong) a youtuber named The Pond Guru who says we can convert nitrates into nitrogen by having the right amount of the right bio media, but after watching over a dozen of his videos I'm starting to think he's just a salesman for Biohome media. I have 180g freshwater tropical tank filtered by a 40 gallon sump and a 65 goldfish tank filtered by a canister. I do weekly water tests and changes in order to keep my nitrates below 20ppm. My question to you all is can we naturally complete the nitrogen cycle? Having 0s across the board? Is there a way to cultivate and maintain the BB, to in theory never have to do water changes, to run a truly cycled tank?

 

Yes it works, the anaerobic bacteria convert NO3 into nitrogen gas.... same idea using pathos plants, they are extremely efficient at up taking NO3 leaving you with with 0's across the board.


Only problem, many other compounds build up in the system without water changes... It's a nasty topic to get into, but I prefer large water changes to keep NO3 in a low range, and for preventative maintenance over reactive maintenance.

I don't go off of NO3 test levels, too much inaccuracy. I dose 10-15ppm NO3 after a 50% or greater water change, plus fish waste. Overall my tank stays ~20ppm with plant uptake matching livestock production.

 

How do you get the anaerobic bacteria to grow?

 

How do you get the anaerobic bacteria to grow?

Anaerobic filter media... Deep pores where O2 has a hard time reaching. Lava rock, Seachem Matrix.

TBH it's a neat topic to talk about, but not so much to dive into in reality. Easier ways to keep NO3 low ... water changes. Grab a python to make life easier.

 

Haha! Thanks, that's pretty much what I thought. I don't mind water changes they're pretty easy for me to do and its just part of the hobby, I enjoy it.

 

My understanding is that the bacteria involved are not special "anaerobic" bacteria, but bacteria that have different biological processes depending on the amount of oxygen available. When there's enough oxygen available they use that and leave the nitrates alone. When free oxygen is sufficiently low, these bacteria strip the oxygen from the nitrates, leaving behind just nitrogen gas. So the key is not so much promoting the growth of a particular bacteria, but in providing the conditions necessary for the bacteria to convert to this nitrate consuming process.

In addition to the Pond Guru, you might be interested in the videos by Dr. Kevin Novak. I'll warn you, they are not the most exciting things on YouTube, consisting mostly of B-roll of his aquarium while he talks over it, but he has a number of very interesting ideas about creating the anoxic zones needed to deal with nitrates.

I have to disagree with ChanyI concerning lava rock for creating anoxic zones. Lava rock is full of holes, but the holes don't connect to the exterior. As a filter media you'd be far better off with filter foam than lava rock.

If you look around in the forums here you'll find a few threads where processing of nitrates is discussed. There are a few people who've used reverse flow undergravel filters to create anoxic zones in the substrate. Others have used Matrix or Biohome or Substrat Pro. I think Fluval Biomax is also supposed to be good. The key here is having a very porous media with extremely low water flow through the interior.

As ChanyI said, this won't eliminate the need for water changes, but the frequency and the amount can be greatly reduced if you're not dealing with trying to remove nitrates with the water change.

 

Anaerobic filter media... Deep pores where O2 has a hard time reaching. Lava rock, Seachem Matrix.

FYI, lava rock is probably the worst stuff to use. It’s not porous at all. Check here why.

Aquarium Information - Alternative Fishkeeping

 

Great! Thank you for your input!

 

Ive seen guppy breeder bury a box filter or spoonge filter in a clear plastic bowl and surround it with rocks. When I tried it it seemed like the rocks around it grew anerobic bacteria, which will eat the areobic bacteria on the filter itself.

 

Ive seen guppy breeder bury a box filter or spoonge filter in a clear plastic bowl and surround it with rocks. When I tried it it seemed like the rocks around it grew anerobic bacteria, which will eat the areobic bacteria on the filter itself.

Anaerobic bacteria grow only in environments that contain no oxygen. The presence of oxygen will cause them to die. Aerobic bacteria need levels of oxygen that would be deadly to anaerobic bacteria. Whatever it was that you thought was eating your aerobic bacteria, it wasn't anaerobic bacteria.

 

are you a microbiologist or something? If not than ill take your opinion as an opinion and not facts. Its very possibly your correct and I'm wrong. I haven't put much thought into it. But I know the rocks smelled funny and the sponge wasn't clogged. My nitrates stayed low. There must be a reason behind doing this. I was using lava rocks. And I know what anaerobic smells like.

 

I just got out of microbio and have the textbook still, I'm gonna back up JayH here, it wasn't anaerobic bacteria eating your aerobes. He is talking about facultative anaerobes, meaning they use oxygen when they can, and other chemical processes when they can't. Your bacterial colonies were likely just switching respiration processes.