an interesting youtube post on the subject of nitrate removal http://www.youtube.com/watch?v=y-H8W7YV ... 1g&lf=plcp
dunc
nitrate removal
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Manky Sanke
- Site Admin
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Re: nitrate removal
I love it!!!! While you lot are burping after your Christmas dinners and watching the Great Escape or Mary Poppins yet again, I'll be watching those videos instead.
Some of my favourite bugs are living in those filters, along with a whole host of micro fauna (tiny creatures, mostly invisible except under a microscope or high magnification).
They work on a long established principle that certain types of bug, my favourite facultative anaerobic thingies, normally like to breathe oxygen by taking it direct from dissolved oxygen in the water but when there is very little available, they switch to obtaining oxygen by sort of "sucking" it off of chemicals such as nitrate.
Nitrate (NO3) is one atom of nitrogen stuck to three atoms of oxygen. If these bugs remove all three of these oxygen atoms from the nitrate, all that is left is the nitrogen. Nitrogen is a gas which will then be dissolved in the water but which will bubble away to the atmosphere at the first opportunity in the same way as carbon dioxide does, especially when there is aeration. So nitrate goes in to the filter but only nitrogen gas comes out.
I haven't been able to find definitive proof yet but I'm certain that they will remove phosphate (PO4) in the same way. These bugs need phosporous to make a vital chemical called ATP (I'll explain if anyone is unwise enough to ask!). If they remove the four oxygen atoms from phosphate, they not only have the oxygen they needed but they end up with some phosphorous as well.
The only problem that I can see is flow rate. For these facultative bugs to switch from normal aerobic respiration to getting their oxygen by reducing nitrate to nitrogen gas, the dissolved oxygen in the water has to drop to about 0.5 to 1.5 mg/L. Fish would die long before that level so we keep the dissolved oxygen in our ponds at 6 mg/L or higher.
The water going into this unit contains far too much oxygen to make them switch so, if the flow rate was high, the normal nitrogen cycle would take place in there and more nitrate would come out than went in! It would just become another bog standard biological filter.
But the clever trick is that by reducing the flow of water into the container, normal nitrogen cycle stuff (adding to the nitrate level) occurs near the top but this uses a lot of oxygen. As the water flows through the media and this process continues, the oxygen level falls until there isn't enough to support nitrogen cycle bugs. This is where the facultative anaerobes have to switch to getting their oxygen from nitrate. They reduce all the nitrate produced by their nitrogen cycle cousins near the top of the media and also any nitrate that was already in the incoming water.
These filters are fine for small volumes of water such as in aquariums but the slow flow rate is never going to be sufficient to process enough water to make any difference to a koi pond.
Unless..... some enterprising DIY fan on here makes a scaled up version in a blue 55 gallon water butt. The design will be simple, a spray bar at the top, some dense foam media that can be taken out and rinsed, to prevent it from becoming totally anaerobic if it starts to silt up, and the water can just trickle out of the bottom and run by gravity back to the pond. Pretty much the same as a trickle tower but with foam as the media.
Some of my favourite bugs are living in those filters, along with a whole host of micro fauna (tiny creatures, mostly invisible except under a microscope or high magnification).
They work on a long established principle that certain types of bug, my favourite facultative anaerobic thingies, normally like to breathe oxygen by taking it direct from dissolved oxygen in the water but when there is very little available, they switch to obtaining oxygen by sort of "sucking" it off of chemicals such as nitrate.
Nitrate (NO3) is one atom of nitrogen stuck to three atoms of oxygen. If these bugs remove all three of these oxygen atoms from the nitrate, all that is left is the nitrogen. Nitrogen is a gas which will then be dissolved in the water but which will bubble away to the atmosphere at the first opportunity in the same way as carbon dioxide does, especially when there is aeration. So nitrate goes in to the filter but only nitrogen gas comes out.
I haven't been able to find definitive proof yet but I'm certain that they will remove phosphate (PO4) in the same way. These bugs need phosporous to make a vital chemical called ATP (I'll explain if anyone is unwise enough to ask!). If they remove the four oxygen atoms from phosphate, they not only have the oxygen they needed but they end up with some phosphorous as well.
The only problem that I can see is flow rate. For these facultative bugs to switch from normal aerobic respiration to getting their oxygen by reducing nitrate to nitrogen gas, the dissolved oxygen in the water has to drop to about 0.5 to 1.5 mg/L. Fish would die long before that level so we keep the dissolved oxygen in our ponds at 6 mg/L or higher.
The water going into this unit contains far too much oxygen to make them switch so, if the flow rate was high, the normal nitrogen cycle would take place in there and more nitrate would come out than went in! It would just become another bog standard biological filter.
But the clever trick is that by reducing the flow of water into the container, normal nitrogen cycle stuff (adding to the nitrate level) occurs near the top but this uses a lot of oxygen. As the water flows through the media and this process continues, the oxygen level falls until there isn't enough to support nitrogen cycle bugs. This is where the facultative anaerobes have to switch to getting their oxygen from nitrate. They reduce all the nitrate produced by their nitrogen cycle cousins near the top of the media and also any nitrate that was already in the incoming water.
These filters are fine for small volumes of water such as in aquariums but the slow flow rate is never going to be sufficient to process enough water to make any difference to a koi pond.
Unless..... some enterprising DIY fan on here makes a scaled up version in a blue 55 gallon water butt. The design will be simple, a spray bar at the top, some dense foam media that can be taken out and rinsed, to prevent it from becoming totally anaerobic if it starts to silt up, and the water can just trickle out of the bottom and run by gravity back to the pond. Pretty much the same as a trickle tower but with foam as the media.
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Koi Man Dave
- Nurse Shark
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- Location: Essex
Re: nitrate removal
vey good if it works as good as they say what a cracking idea.
Recharge it twice week with a squirt of vodka that will be one for the Aquaripure filter and one for me.
Maybe not in my case as i dont drink.
If you had one of these on a pond you would have to have shares in Vodka given the amount needed to recharge it.
Probably great on a tank but maybe not so good on a pond maybe worth an experiment though if it claims what it states on the tin then what a cracking idea.
Recharge it twice week with a squirt of vodka that will be one for the Aquaripure filter and one for me.
Maybe not in my case as i dont drink.
If you had one of these on a pond you would have to have shares in Vodka given the amount needed to recharge it.
Probably great on a tank but maybe not so good on a pond maybe worth an experiment though if it claims what it states on the tin then what a cracking idea.