Getting rid of nitrates
- Thread starter MFK_23
- Start date
Just continuing this topic, I just heard about a product(bio media) by Seachem called De*nitrate, which supposedly removes nitrates when water is passed through the media at a rate of 50gph or less. Apparently aerobic bacteria on the outside of the media consumes the O2 in the water allowing anaerobic bacteria in the center of the media to remove nitrates.
I am not sure how effective this is compared to a coil de-nitrator, but its a lot simpler to set-up a de-nitrator device using this stuff.
There is guy I saw on another forum who used about 1 foot of 150mm dia PVC pipe filled with this stuff, plumbed an entry in one end and exit on the other, calibrated the flow through the device and there you have it! Even if this isnt as effective at removing all nitrates as a coil de-nitrator in a single pass, it flows a lot more water and so the water will pass through it more often.
Has anyone experimented with this stuff? I'm thinking I'll give it a go. Of course regular water changes will still be observed but if I can keep nitrates down then the fish should be happier in between changes and if I can reduce WC's to every 2 weeks then they wont need to be disturbed and stressed as often = happier fish and less work for me!
I am not sure how effective this is compared to a coil de-nitrator, but its a lot simpler to set-up a de-nitrator device using this stuff.
There is guy I saw on another forum who used about 1 foot of 150mm dia PVC pipe filled with this stuff, plumbed an entry in one end and exit on the other, calibrated the flow through the device and there you have it! Even if this isnt as effective at removing all nitrates as a coil de-nitrator in a single pass, it flows a lot more water and so the water will pass through it more often.
Has anyone experimented with this stuff? I'm thinking I'll give it a go. Of course regular water changes will still be observed but if I can keep nitrates down then the fish should be happier in between changes and if I can reduce WC's to every 2 weeks then they wont need to be disturbed and stressed as often = happier fish and less work for me!
Miles said:
Miles is partly right, plants can use both nitrates and ammonia. The most common fertilizer is ammonium nitrate(NH4NO3) which releases ammonia (NH3). The "-NO3" group makes the whole molecule more soluble in water. Other fertilizers are
ammonium sulfate, diammonium phosphate and monoammonium phosphate. Note that all have ammonia which gets released so the fertilizers are actually ammonia based, not nitrate based.
If there is no fish in a tank to produce ammonia, the plants will have no choice but to use nitrates form the water. However there will be no nitrates at all, since no bacteria will get ammonia(no fish) to produce it. So one possible solution to get rid of the nitrates is to get the fish out, leave the plants in and wait
BTW, the solubility of the "-NO3" is also used when one needs to increase the potassium concentration: potassium nitrate (KNO3) is added.
With all that, it is more likely that plants reduce the nitrates by using the ammonia in a tank, thus not allowing it to be turned by the biofilter into nitrates (Miles' idea)
In a tank populated with fish the Liebig's Law never points to nitrogen based compounds. They are always in greater concentration than the rest of the nutritients a plant needs. That is always true unless a 90% water change is made every 30 mins
Regards
Howdy Half,
and welcome to MFK. Where in Germany are you from?
Compare your post to mine, and you'll find out that we are not as far apart as you might think.
Certainly, and as I said before, plants can use nitrogen in any oxidation state. However, if their primary nitrogen source was ammonia or nitrite, keeping fish and plants would be mutually exclusive: To satisfy the plants nitrogen requirements, the levels of nitrite or ammonia would have to be so high that they'd be toxic to fish. Fortunately, plants like nitrate best.
The reason that the primary component of fertilizers is ammonia is simple, it's an economical aspect: The Haber-Bosch-Verfahren, invented 1910 allows the fixation of atmospheric nitrogen to ammonia for real cheap. And since nitrogen is the primary limiting factor in agriculture, plants take whatever they get, in this case ammonia. Converting the fertilizer to nitrates before administering it to the fields is uneconomical, since ammonia is usable by plants. Since nitrogen is limited (Liebig's Law), they take it up. As I stated before, nitrogen is not limiting according to Liebig's law in our aquariums.
Bottom line: If plants were to rely on ammonia or nitrite, we wouldn't be able keep fish in our planted tanks.
Okay, I quit beating this horse
HarleyK
and welcome to MFK. Where in Germany are you from?
Compare your post to mine, and you'll find out that we are not as far apart as you might think.
Certainly, and as I said before, plants can use nitrogen in any oxidation state. However, if their primary nitrogen source was ammonia or nitrite, keeping fish and plants would be mutually exclusive: To satisfy the plants nitrogen requirements, the levels of nitrite or ammonia would have to be so high that they'd be toxic to fish. Fortunately, plants like nitrate best. The reason that the primary component of fertilizers is ammonia is simple, it's an economical aspect: The Haber-Bosch-Verfahren, invented 1910 allows the fixation of atmospheric nitrogen to ammonia for real cheap. And since nitrogen is the primary limiting factor in agriculture, plants take whatever they get, in this case ammonia. Converting the fertilizer to nitrates before administering it to the fields is uneconomical, since ammonia is usable by plants. Since nitrogen is limited (Liebig's Law), they take it up. As I stated before, nitrogen is not limiting according to Liebig's law in our aquariums.
Bottom line: If plants were to rely on ammonia or nitrite, we wouldn't be able keep fish in our planted tanks.
Okay, I quit beating this horse
HarleyK
Thx for the welcome, HarleyK. I am from NRW, near Dusseldorf. You seem to be often in Europe
Even deeper bottom line if allowed, in a small scale self contained system there is no way to get rid of nitrates without introducing something regularly (water, sulfur, anaerobic cultures). One thing I read here, with chemistry one is bound to screw up sooner or later and the result will be dead fish.
Regards
Even deeper bottom line if allowed, in a small scale self contained system there is no way to get rid of nitrates without introducing something regularly (water, sulfur, anaerobic cultures). One thing I read here, with chemistry one is bound to screw up sooner or later and the result will be dead fish.
Regards
