Anoxic filtration

[ColdKoi]

Anyone else been watching Kevin Novaks YouTube videos and how he’s setting up an under gravel plenum for anoxic filtration?

I thought under gravel filtration was dead as the dodo but he seems to have a clever idea there using it to create an anoxic environment.

Was thinking of re-scaping the 75 since I’m not really flattered about how it turned out (was just working with what I had and could get) and nothings really established in there yet. Be a good opportunity to maybe try out this idea…

 

[Joe_D]

I had an UG filter years ago and found that it was not a good idea.....at least for an Aquarium with fish
Yes, it will give you crystal clear water for a little while.

However, it just pulls crap into the substrate where it can not be removed and and evidently raises nitrate levels. This led many to take out their UG filters.

We now have better filters and better knowledge of the chemistry involved to know better

 

[ColdKoi]

Take a look into what I’m talking about. This isn’t your typical old school undergravel filtration of the 70s. It’s a plenum with very little water flow crating an anoxic environment for bacteria to reduce nitrates (that’s the whole purpose of it)

This isn’t your main filtration, it is providing the nitrate reduction bio part as well as nourishing the plants. Main mechanical and bio is still accomplished with a canister setup (or hob I guess)

 

[Joe_D]

Why would you create anoxic environment if you are going to add fish?
What am I missing here?

I any event, , it still has the same drawbacks as i mentioned , even if it is not the main filter ..

 

[ColdKoi]

Because nobody likes nitrates….? Lol

It’s nitrate reduction, as well as plant nutrition.

Look into it, you’ve obviously got no clue what I’m talking about. The guy runs setups 5+ years and the substrate remains in perfect condition and little to none nitrate, basically just minimal water changes more for topping off than anything.

This isn’t your typical 1970s 300gph undergravel filter that was a pile of junk.

 

[paparam]

I have a medical degree with extensive knowledge of microbiology, organic chemistry and science in general. What Dr. Novacks states makes absolute sense. He has run tanks for years. People have a knee jerk reaction to under gravel filter- that is not his system at all. He is advocating a balanced system with plants, fish and the resultant oxygen level gradient through the water column. He is using a raised plenum and has had great success even with his goldfish tank.
The benefits:
-makes the hobby very affordable as one not relying on equipment and chemicals that drive the cost up considerably.
-makes the caring for fish a lot less arduous with fewer water changes

The concept of a balanced ecological system is not new at all. Look around and you will see it in action wherever nature is allowed to take its on course. We are the ones who ruin things driven by a profit motive.
I would recommend following his system as explained in detail in his step by step videos. He is not the greatest or most succinct speaker but clearly knows his biology.He did not invent the system- just took what has been known for decades and adapted his tanks to make life easier on himself, his fish and plants

 

[Mr. Overfilter]

Anyone else been watching Kevin Novaks YouTube videos and how he’s setting up an under gravel plenum for anoxic filtration?

I am now. My problem with UGF was based on using it once and then trying to clean it. What a mess! Based on what I've been reading lately, I'm for trying an algae scrubber as a weapon in the nitrate war.

 

[ColdKoi]

Yea, he definitely seems like he knows what he’s talking about. Albeit not a very good personality for lecturing, it’s hard to listen to a whole video clip, he just drones on and on lol

I’ve got the plates and a few goodies ordered up, I’m going to try this on my 75 just for kicks. But I’m probably going to hold off till April or so, I want to do this when I’m going to be home and able to monitor the tank for the first few days to make sure everything is good. I’m sure nothings going to happen, but who likes to set up a tank and go away for work for a couple days only to find a floater or 2 rotting away!

 

[Caliban07]

My issue with the plenum system here is that this can be achieved naturally in long time submerged substrates. The redox levels that are required in order to facilitate nitrate removal are not constant in our tanks, not where there are plants at least.

As you go down the substrate layers the oxygen will deplete and in the niches or certain redox potentials microbes will exist that carry out all kinds of natural functions. Nitrate removal, Iron reduction, sulphate production and so on.

Plants offer oxygen to microbes at the tips of their roots in exchange for essential nutrients. Their area is called the rhizosphere. This is where redox potential will fluctuate and give life to all kinds of microbes. A diverse range that fluctuate as the roots move through the substrate and the rhizosphere changes.

You can have tanks run without nitrates without using an odd looking gap style plenum. You just need time.

 

[paparam]

Yea, he definitely seems like he knows what he’s talking about. Albeit not a very good personality for lecturing, it’s hard to listen to a whole video clip, he just drones on and on lol

My Tip on listening to his You Tube videos: First switch on subtitles. Second change speed (the clock icon) to 1.5x or more. He becomes surprisingly easier to get through the video!!

 

[ColdKoi]

My issue with the plenum system here is that this can be achieved naturally in long time submerged substrates. The redox levels that are required in order to facilitate nitrate removal are not constant in our tanks, not where there are plants at least.

As you go down the substrate layers the oxygen will deplete and in the niches or certain redox potentials microbes will exist that carry out all kinds of natural functions. Nitrate removal, Iron reduction, sulphate production and so on.

Plants offer oxygen to microbes at the tips of their roots in exchange for essential nutrients. Their area is called the rhizosphere. This is where redox potential will fluctuate and give life to all kinds of microbes. A diverse range that fluctuate as the roots move through the substrate and the rhizosphere changes.

You can have tanks run without nitrates without using an odd looking gap style plenum. You just need time.

I get that a similar scenario can be achieved with deep substrate, but you don’t have any way of drawing these nutrients and other gunk down into the substrate efficiently. Other than maybe stirring the substrate, but then you disrupt the environment you’re trying to nurture!

I don’t think this is anything that’s going to light the world on fire as a new way to do things. It’s just a different way of doing it. Personally I see this plenum idea as much more appealing than lugging 300Lb of substrate into my house and losing that real estate in the tank

 

[Dallascowboys16]

I watched the video and it is a neat idea, but honestly I think it is overengineering a problem that we don't need to even have. In a planted tank you are often battling to keep your nitrates at readable levels due to rapid consumption when plants are photosynthesizing. I find myself always having to dose nitrates to my heavily planted tanks in order to keep them at acceptable levels (5-10 ppm). I honestly think people tend to really over think their biological filtration. BB grows on any and all surfaces in a tank. I've read quite a few papers on this and the limiting factor 99% of the time in a standard aquatic environment is bio available ammonia, not surface area. That is why I think all of the so called "biological media" that is marketed by aquarium companies (ceramic rings, bioblocks, hyper-porous media, etc) is mostly snake oil.

Now where I think this could be very useful is in large non planted tanks. Creating an Anoxic environment to remove additional nitrogen through Anammox (anaerobic ammonium oxidation) would be very helpful in a system like a large, overstocked peacock cichlid tank that has no plants. Many large cichlid keepers are in a constant battle to keep nitrates low since there is no natural process taking place in their tank on a scale large enough to lower them. Creating a plenum for a tank like that would actually be addressing the problem in a way that many have not thought of before.

Thanks for sharing an interesting video!

 

[ColdKoi]

Yes I’d have to agree, if you’ve got enough plant life in the tank it’s likely not an issue. But, depending on the bioload in the tank, it’s probably going to take a substantial amount of plants to reduce the nitrates to untestable. Anything I’ve looked at where people claim zero nitrate tanks, there’s hardly even room left in the tank to put a fish lol

I still want to increase plant count in my 75 when I find something I like to put in there, and I’d like to have some type of plant that I can basically cover the back glass with. But as it stands right now with about 25% of the substrate planted it’s not enough to handle the bioload of even the juvenile fish in the tank, though the tank is not truly cycled yet, just the filter media I stole from my other tank is handling part of the filter cycle for now.

I don’t really care about making it a self sustaining, full cycle tank. That’ll take all the fun out of it! I just want it to not be a nitrate factory (like my comet tank). I work out of town for several weeks sometimes, and I don’t want to worry about having to send someone over to check/change water. According to the aqadvisor I should have a fairly low stock and lots of filter. But only time can tell

 

[Caliban07]

Yes I’d have to agree, if you’ve got enough plant life in the tank it’s likely not an issue. But, depending on the bioload in the tank, it’s probably going to take a substantial amount of plants to reduce the nitrates to untestable. Anything I’ve looked at where people claim zero nitrate tanks, there’s hardly even room left in the tank to put a fish lol

I still want to increase plant count in my 75 when I find something I like to put in there, and I’d like to have some type of plant that I can basically cover the back glass with. But as it stands right now with about 25% of the substrate planted it’s not enough to handle the bioload of even the juvenile fish in the tank, though the tank is not truly cycled yet, just the filter media I stole from my other tank is handling part of the filter cycle for now.

I don’t really care about making it a self sustaining, full cycle tank. That’ll take all the fun out of it! I just want it to not be a nitrate factory (like my comet tank). I work out of town for several weeks sometimes, and I don’t want to worry about having to send someone over to check/change water. According to the aqadvisor I should have a fairly low stock and lots of filter. But only time can tell

Use a floating plant like Duckweed, Amazon Frogbit or Salvinia. Full access to atmospheric co2 and tons of light means they will grow rapidly and help with your nitrate problem. Just scoop and compost every now and then.

 

[ColdKoi]

I was thinking of something like that a while back but there’s none available around this neck of the woods. I also wasn’t super keen on blocking light to the rest of the plants as some of them really like a good blast of light.

I wouldn’t say I’ve got a nitrate problem. I just don’t want it to become one in the future. I’d rather be proactive than reactive.

Right now the tank can hold its own for several weeks without the nitrates being excessively high by any means. But who knows what it will be like in a year or 2 when the fish mature

 

[el chibcha]

Did you end up setting up up the 75 tank on anoxic filtration?
Would like to know how it went
I just started research on this
Regards

 

[ColdKoi]

No I haven’t. If I’m going to tear up the tank it won’t be for a month or 2 till I’m home daily again to keep an eye on things