# aquatic plants and nitrate



## PhishNeslo (Dec 20, 2002)

i just read in a book ("Dynamic Aquaria") that aquatic plants cant take up nitrogen as found in nitrate, only terrestrial plants can use it (through their roots, i think). apparently aquatic plants get their nitrogen from ammonium and a few other nitrogeneous compounds. does this seem strange to anyone else? i always thought plants used nitrate . . . i know my algae sure grows when it is around, but i think alage might be different than higher aquatic plants.

phil


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## SNPiccolo5 (Oct 6, 2002)

Well, if you book says that aquatic plants simply *don't* use nitrate, that is wrong, because people have run into 0 nitrate problems with plants, so the plants are obviously using the nitrate. 

But plants also use ammonia, which is why many people run into 0 nitrates, your biological filter can't produce nitrate without ammonia, so if the plants outcompete the bacteria for the ammonia, there can't be nitrate.

Aquatic plants use both ammonia and nitrate, some plants prefer ammonia over nitrate. If you test for ammonia though, it should be zero, not like nitrates where 5-10 ppm is ideal. Hope this helps!

-Tim


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## GulfCoastAquarian (Jul 30, 2002)

If I remember correctly, plants need to utilize energy to convert nitrate to nitrite to ammonia internally before they can use it. That's why aquatic plants "prefer" ammonia over nitrate.


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## PhishNeslo (Dec 20, 2002)

ahh. that makes sense. thanks gulf coast


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## m.lemay (Jul 28, 2002)

Gulfcoast is correct. Plants have to convert nitrates back to ammonia to use it. Thats also why some of the more effective fertilizers for terrestrial plants list some form of ammonia or urea as thier nitrogen source.

Theres an interesting discussion going on at the Aquabotanic site about using miracle grow as a fertilizer for planted tanks. Yes, Miracle-Grow, The stuff you use on your tomatoes.

Rumor has it that someone who has contributed much to this hobby is using this in his tanks. The debate is raging about the ammonia contained in Miracle-grow will kill the fish, and the Phosphate ratio is too high and will create an out of control algae bloom. The phosphate debate is hot and many people are now saying that phosphate is not the planted tanks boogey man as it was cracked up to be 10 years ago. The discussion even goes on to say that by limiting phosphate we are promoting certain types of algae that feed on nitrates.
Interesting stuff!

Marcel


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## SNPiccolo5 (Oct 6, 2002)

Miracle grow?!?! That can't be good even if it does have the right ammonia for plants! Jobes sticks is one thing, but miracle grow... people will be using vaccums to empty their tanks before I use miracle grow (the regular kind) on my aquatic plants!

-Tim


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## m.lemay (Jul 28, 2002)

I thought I'd raise some eyebrows with that one!!!:hehe:

I don't think I'm ready to add Miracle grow to my tank either, but the discussion is pretty hot. I, for one, don't believe that the N-P-K ratios are correct for a planted fish tank.

From what I've been reading, This is what you should shoot for in your tank:

Nitrates=5-10ppm
Phosphates=0.5-1.0ppm
Pottasium=20ppm

I think that for most of us, pottasium is the week link in our tanks because its used up by plants in large quantities and does not get replaced by feeding the fish.:angel:


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## SNPiccolo5 (Oct 6, 2002)

Pottasium....that is the one thing I look for in fertalizers. I don't think too many people (outside this forum) realize K is actually a macro-nutrient of plants!

-Tim


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## GulfCoastAquarian (Jul 30, 2002)

Does anyone know what sort of increase per gallon one might see by adding Stump Remover? Potassium Nitrate (KNO3) is generally used to supplement nitrates and I add it every few weeks. I'm just wondering how much potassium my tank is getting out of it at the same time.


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## lanstar (Nov 29, 2002)

> _Originally posted by GulfCoastAquarian_
> Does anyone know what sort of increase per gallon one might see by adding Stump Remover?


I've heard that the only "active" ingredient in Stump Remover is KNO3. However, I've been told that some manufacturers of stump remover don't worry too much about how pure their product is. I guess I can understand that, if you are using it for their intended purpose, a little impurity wouldn't matter. Some brands are said to contain traces of other stuff, like arsenic. 

I found a fireworks supply house that had some "food grade" KNO3 they got a good deal on and were selling cheaper than their "fireworks grade" KNO3. However, they're sold out... and you had to buy 25 lbs of the stuff, minimum!

In any event, I ran across a web page where a guy as put up a dosage calculator for aquarium plant fertilizer elements. If you're adding individual suppliments, you might find it useful.

The link is: http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

Take care...

Tim


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## m.lemay (Jul 28, 2002)

The web page lanstars pointing at is an awesome page for fertilizers and how much to dose. Just about everybody I know who doses thier own fertilezers use this page for guidance. The rest of the site's pretty cool also.

Marcel:bounce:


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## Steve Hampton (Jul 22, 2002)

> _Originally posted by GulfCoastAquarian_
> Does anyone know what sort of increase per gallon one might see by adding Stump Remover? Potassium Nitrate (KNO3) is generally used to supplement nitrates and I add it every few weeks. I'm just wondering how much potassium my tank is getting out of it at the same time.


For 1.0ppm increase in nitrate using KNO3, you will also be raising potassium by 0.63ppm. This is obviously way too small of an addition of K+ and is why people add KCl or K2SO4 for potassium.

For example I add both KNO3 and KCl. The rate of addition of K+ comes from 0.31ppm from the KNO3 and 0.68ppm from the KCl so that each ml I add to my tanks is adding 1ppm of K+ when combined.


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## PlantumOfTheOpera (Mar 12, 2003)

m.lemay said:


> Gulfcoast is correct. Plants have to convert nitrates back to ammonia to use it. Thats also why some of the more effective fertilizers for terrestrial plants list some form of ammonia or urea as thier nitrogen source.
> 
> Theres an interesting discussion going on at the Aquabotanic site about using miracle grow as a fertilizer for planted tanks. Yes, Miracle-Grow, The stuff you use on your tomatoes.
> 
> ...



Any chance you can point me to this discussion? I have searched but as of yet been unable to locate it at the wet thumb forum. Thanks!


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## kor4ever (Feb 26, 2003)

Here plantum, you needed to look at the archived forum as this is an old thread.

http://www.aquabotanic.com/boards/viewtopic.php?t=2276&highlight=miracle

Felix


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## PlantumOfTheOpera (Mar 12, 2003)

Thanks Felix,

As I have stated in my prvious posts, I used Miracle-gro with tremendous success in the past. Re-enetering the hobby now, I have read much on differing opinions. 

Suffice it to say, I am convinced that MG or any fert used judiciously can work. FWIW, though there is high Urea in MG, I have never had fish deaths. 

Simazine, probably another "dirty" word also works well in small quantities. As in life, no method works for all situations, and Simazine will kill certain plants. In a similar vein, instead of using copper sulfate drops if and when an ich breack-out occurred [ usu from a latently infected new aqusition] i kept 2-3 pennies in the tank. Later, I discovered that they were doing in my Vals.

As the excellent PMDD article states, they are proposing a starting point. 

If others are using MG, I would like to hear from them. This seems like a nice forum for discussions, w/o the silliness of flames.


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