Getting rid of nitrates

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HarleyK said:
. Note: agricultural fertilizers are nitrate based. For a good reason.

They also contain Urea, which is Ammonia.. right?


Also.. If you take a tank full of Nitrates which has no other incoming Ammonia/Nitrites.. and put a floating bunch of plants in there, how long will it live without the combination of Ammonia/Nitrite/Nitrates all present in the water? In my planted refugium, I have huge bundles of hornwart die off if theres not enough fish waste being constantly put off into the system, even if my nitrates are close to 100ppm..

This bugs me now, I am going to have to do some tests..

Just a thought..
 
Sry Miles i meant Nitrates, in the last sentence. Thanks for the replies.

Do u think that a smaller sand filter will still contain bacteria that remove nitrate? Do u think it is mainly the size of the sand filter used in the large aquariums that results in the cultivation of the nitrate bacteria, or the conditions inside the filter caused by the sand. I also heard that nitrate consuming bacteria is anerobic, meaning that they grow in areas that are lacking air.
 
Only anaerobic can remove nitrates, your fbf has aerobic bacteria as oxygen rich water flows in and gets filtered. However bacteria house is different i guess as it claims 0 nitrate readings in the filtered water even under non-anaerobic conditions.
 
MFK_23 said:
Sry Miles i meant Nitrates, in the last sentence. Thanks for the replies.

Do u think that a smaller sand filter will still contain bacteria that remove nitrate? Do u think it is mainly the size of the sand filter used in the large aquariums that results in the cultivation of the nitrate bacteria, or the conditions inside the filter caused by the sand. I also heard that nitrate consuming bacteria is anerobic, meaning that they grow in areas that are lacking air.


To be honest with you, I am unsure. The previous info provided about nitrate consuming bacteria was good. I am unsure if any of these methods are practical for home use however.. That is why I would suggest a planted veggie filter.
 
Howdy,


Miles said:
Nitrates are used VERY little by plants, but infact it is Ammonia/Nitrite that is consumed by plants in the prior stages of the nitrogen cycle.

:grinno:


Miles said:
[Fertilizers] also contain Urea, which is Ammonia.. right?

:grinno:


Okay, let's do some chemistry and toxicology:
Urea is OC(NH2)2, ammonia NH3 (sorry, I don't know how to use subscript here). Two different things. Ammonia and nitrites are highly toxic, urea isn't really. You will not find too many fish in a tank with either ammonia or nitrites significantly above their detection limit (in hobby-targeted analytics like these drop tests we all use). Plants don't eat them, either. It's bacteria that convert them into nitrates, which are taken up by plants. In bad situations, other bacteria convert them into ammonia. These bacteria are not our friends. In a functioning biofilter, these bad bacteria are far outnumbered by those who create nitrates.

Miles said:
If you take a tank full of Nitrates which has no other incoming Ammonia/Nitrites.. and put a floating bunch of plants in there, how long will it live without the combination of Ammonia/Nitrite/Nitrates all present in the water?

They will do just fine without ammonia and nitrites. However, Liebig's Law of the Minimum applies: It means the rarest nutrient an organism requires will be the limiting factor to its growth. No plant can live on nitrates alone. In agriculture, however, nitrates are the limiting factor (which are converted from urea by aerobic bacteria). In most lakes, that's phosphates. That's why the laundry detergents used in the 70s/80s caused trememdeous algae bloom. They stopped using phosphates since. At least in Europe, I don't know about the US. Okay. In our tanks, it's generally nitrates that are in excess. Comes from all the good fish food, especially for carnivores. If you have plenty of plants in your tank, Miles, and you still have 100 ppm nitrates, then I suggest two things: 1) you should use aquatic plant fertilizer. Name brands contain no nitrate (if in doubt test them before you use them). They add the growth-limiting nutrients to your tank, so that they no longer keep your plants on a short leash (by Liebig's Law). And as they grow better and healthier, they will use up much more nitrates. 2) Check your tap water for nitrates, it might be the culprit.

MFK_23, the fertilizing aspect is something I forgot to suggest to you in my last reply. If you have plenty of plants and still high levels of nitrates, add some fertilizer on a regular basis. Again, test it for nitrates and phosphates before you use it. It might be hard to find the limiting nutrient by conventional water test for the hobby. Often it's trace elements like manganese or such that are too low. Dupla has good daily fertilizers in liquid form, that contain all of that.

However, be aware of productes by Tetra. For example, they add phosphates to their peat extract :swear: . That will add another nutrient to your tank, which you already have plenty of. These products cause algae bloom. Also, Their Easy Balance is against anything that nature stands for. I like their tap water conditioner, though. I don't really know if it is allowed here to name brand names. If not, moderator, please only censor the last paragraph and not the entire thread.

All the best,

HarleyK
 
HarleyK said:
Howdy,

Okay, let's do some chemistry and toxicology:
Urea is OC(NH2)2, ammonia NH3 (sorry, I don't know how to use subscript here). Two different things. Ammonia and nitrites are highly toxic, urea isn't really. You will not find too many fish in a tank with either ammonia or nitrites significantly above their detection limit (in hobby-targeted analytics like these drop tests we all use). Plants don't eat them, either. It's bacteria that convert them into nitrates, which are taken up by plants. In bad situations, other bacteria convert them into ammonia. These bacteria are not our friends. In a functioning biofilter, these bad bacteria are far outnumbered by those who create nitrates.

Good info, now I know.

They will do just fine without ammonia and nitrites. However, Liebig's Law of the Minimum applies: It means the rarest nutrient an organism requires will be the limiting factor to its growth. No plant can live on nitrates alone. In agriculture, however, nitrates are the limiting factor (which are converted from urea by aerobic bacteria).

Are you basing all of your chemical knowledge on what's fact in the 'agriculture' world? Perhaps growing plants under water is different? I am not doubting you, I am just curious. I have talked to a few people about this situation who have kept planted tanks for a number of years, and they both agreed the 'less nitrate' effect you see is often plants eating ammonia/nitrite in different stages. I also see this in some books.

If you have plenty of plants in your tank, Miles, and you still have 100 ppm nitrates, then I suggest two things: 1) you should use aquatic plant fertilizer. Name brands contain no nitrate (if in doubt test them before you use them). They add the growth-limiting nutrients to your tank, so that they no longer keep your plants on a short leash (by Liebig's Law). And as they grow better and healthier, they will use up much more nitrates. 2) Check your tap water for nitrates, it might be the culprit.

I have 100ppm nitrates because the 'planted tank' I have is actually a planted refugium veggie filter. It's a 470g system, and I will often keep thousands of fish in the tanks, or a bunch of hungry stingrays. I don't use fertilizers, because I do daily water changes, and our tap water has plenty of nutrients in it to keep the plants healthy. (Swords and Grasses).. I have never had an Ammonia spike on the planted system, even when I add a ton of fish to it. The Nitrates seem to never get really low, but I don't do 'massive' water changes by any means, just 50-70g/day, as I don't want to drop the temp too much. With the high nitrates in my tanks, why would I have huge bundles of Hornwart die off? Lack of Nutrient balance I am assuming? I was told it was the lack of the ammonia being present in the water, because plants need a make-up of all 3 components to thrive.

Interesting there are very little river systems in the wild that have Nitrates in the water, yet plants still grow abundantly. I am probably making a stupid statement however, as there is alot I have to learn about scenarios in the wild.

Many of the reefkeepers I have talked to agree that the vegetation 'Calurpa' in a SW tank needs a steady flow of Ammona/Ni/Na to stay healthy, or it will die off. I have witnessed this happen first hand in my tank. I held off feeding my tank for a week, and my entire bunch of plants died off, even though Nitrates in the SW tank were at a steady 20-40ppm.

Regardless, great info. I am going to have to take this discussion to a forum with a bunch of planted tank buffs ;) I am no water chemistry genuis by any means.

Miles
 
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