# How munch urea to dose?



## Brian3 (Jan 14, 2008)

I have urea CO(NH2)2 I can make a solution of it. Still I dont know how is too much urea. Im thinking about 3% or 4% of urea solution.

Thank you.


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## Brian3 (Jan 14, 2008)

Also I can mix 3 diferent chelated irons to a solution?


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## Hoppy (Dec 24, 2005)

It is risky to dose urea in an aquarium. Can't you get a nitrate compound, like potassium nitrate, or calcium nitrate to use instead?


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## Brian3 (Jan 14, 2008)

Yeah I just mixed KNO3 and DTPA, EDTA and Gluconate irons, also MnSO4. Still I want to dose urea for the next time, just a little in the mix to have a little amonnia source.


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## Darkblade48 (Jan 4, 2008)

You can definitely mix different chelated iron chemicals together. You can even mix them with KNO3 and the MgSO4 as you have already done.

You cannot mix it with KH2PO4, just to let you know.

Also, as Hoppy mentioned, you should not be dosing urea into your aquarium. Why do you want to add ammonia to your aquarium?


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## OverStocked (May 26, 2007)

Pfertz and RootMedic customers have been adding urea to there aquarium for a very long time with no problems. Ammonical Nitrogen is very rapidly taken up by plants and is preferred by most plants over potassium-nitrogen compounds. Using Urea allows you to up your nitrogen levels in solution that would otherwise be unobtainable, particularly due to potassium solubility. It is popularly used in solutions due to this. 

The "ammonia" in synthetic urea is actually ammonium and is significantly less toxic than ammonia. I've been dosing and testing urea based fertilizers in aquariums for nearly 10 years with no problem. 

I'm not going to give a recommendation on how much urea to use in your solution, because that would be silly for me to do. I will say you can do it and be 100% safe. 

Somewhere between 10-20g per liter is a stable safe place to work. Remember that in solution, the more you dissolve the harder it will be to dissolve potassium.


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## Brian3 (Jan 14, 2008)

Thankyou. Yeah I only want a small amount that dont produce secondary effects. It will be sucked up by plants fast anyway.

Thanks Over Stocked


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## Hoppy (Dec 24, 2005)

But, we don't dose potassium anyway. Potassium dosed into water can result in an explosion! What we dose is potassium nitrate, and long before we run into problems with dissolving enough of that in the tank water, every fish will be dead.

Yes, I know you meant the problem with dissolving it into a premix of water for dosing the tank. But, that too is no problem because we can always adjust the amount of the mix we dose to the tank so it is big enough to dissolve all of the KNO3 and KH2PO4 and K2SO4 that we want to dose at one time. 

Given that the limit on how much urea you can dose before causing problems is very low compared to KNO3, what is the advantage of even trying it? Our efforts would be far more fruitful if devoted to trying to keep the CO2 concentration high enough to let the plants grow at the rate the light drives them to.


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## rmsalaysay (Jan 5, 2016)

Hoppy said:


> But, we don't dose potassium anyway. Potassium dosed into water can result in an explosion! What we dose is potassium nitrate, and long before we run into problems with dissolving enough of that in the tank water, every fish will be dead.
> 
> Yes, I know you meant the problem with dissolving it into a premix of water for dosing the tank. But, that too is no problem because we can always adjust the amount of the mix we dose to the tank so it is big enough to dissolve all of the KNO3 and KH2PO4 and K2SO4 that we want to dose at one time.
> 
> Given that the limit on how much urea you can dose before causing problems is very low compared to KNO3, what is the advantage of even trying it? Our efforts would be far more fruitful if devoted to trying to keep the CO2 concentration high enough to let the plants grow at the rate the light drives them to.


sometimes in some country this kno3 is not allowed unless you are registered chemist. that is why we try hard to find an alternative for kno3, do oyu mind suggest which chemical is the best alternative for kno3?, and be compatible to mix as macro?.

for example if i will go to k2so4 what is the provider for nitrogen?


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## Darkblade48 (Jan 4, 2008)

rmsalaysay said:


> sometimes in some country this kno3 is not allowed unless you are registered chemist. that is why we try hard to find an alternative for kno3, do oyu mind suggest which chemical is the best alternative for kno3?, and be compatible to mix as macro?.
> 
> for example if i will go to k2so4 what is the provider for nitrogen?


Some people use other sources of nitrate (calcium nitrate is usually not regulated as tightly). However, you will have to account for the excess of calcium that is added (i.e. you can do water changes with RO instead to keep hardness from increasing too drastically).

Potassium sulfate does not provide any nitrogen to plants.


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## citrusvrucht (Mar 1, 2016)

I dose 0,5 ppm urea per 100L a day, and if you have a well planted tank it is absolutely safe, I've been doing it for years.
Some plants (like Rotala's) have better colour and bigger leafs, others don't care and show no visible improvement. If I wouldn't notice a difference with urea I wouldn't bother dosing it daily. 
If you want to play it safe, start with 0,1 ppm a day and add 0,1 ppm each week till you reach whatever limit. The limit for me is when algae start to show. 
Plants react better if they have a positive, negative and neutral nitrogen source. It works even better if the NO3 level is not to high.

If you keep the pH of your stock solution low enough by adding an acid (ascorbic, citric,...) you can even mix KH2PO4 with EDTA, HEDTA, DTPA, EDDH(M)A, HBED,... if you want.


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## Hoppy (Dec 24, 2005)

I hope happi will drop in here and comment. He is one of those who do use urea successfully.


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## happi (Dec 18, 2009)

in acid water you can use Urea without any risk, i have used 0.2 to 2 ppm dose in single dose, but there is no benefit of using higher dose more than 0.7 ppm daily in fully planted tank or most of it will convert into NO3. Urea is most beneficial out of all the Nitrogen sources i have tried so far, it can make the plant go wild if used correctly. i would start with 0.5ppm daily without any other source of Nitrogen in the water.


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## Edward (Apr 11, 2005)

happi said:


> in acid water you can use Urea without any risk, i have used 0.2 to 2 ppm dose in single dose, but there is no benefit of using higher dose more than 0.7 ppm daily in fully planted tank or most of it will convert into NO3. Urea is most beneficial out of all the Nitrogen sources i have tried so far, it can make the plant go wild if used correctly. i would start with 0.5ppm daily without any other source of Nitrogen in the water.


 How do you regulate the Urea doses to be safe for the fish?


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## happi (Dec 18, 2009)

Edward said:


> How do you regulate the Urea doses to be safe for the fish?


because i have aqua soil and i use RO water, everything remain acidic in my tank, i also have German blue ram in my tank which never had any issue with Urea dosing even up to 3 ppm in single dose, but like i said there is no benefits of adding too much of it. i try stay away from adding NH4NO3 which seems to cause Algae, even though they both are form of Ammonium but Urea works better and safer IME.


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## Edward (Apr 11, 2005)

rmsalaysay said:


> sometimes in some country this kno3 is not allowed unless you are registered chemist. that is why we try hard to find an alternative for kno3, do oyu mind suggest which chemical is the best alternative for kno3?, and be compatible to mix as macro?


 You can use Ca(NO3)2 when KNO3 is restricted or unavailable. Please see “What if I cannot get KNO3” section for more details.


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## rmsalaysay (Jan 5, 2016)

Edward said:


> You can use Ca(NO3)2 when KNO3 is restricted or unavailable. Please see “What if I cannot get KNO3” section for more details.


thank you so much, i have sent a message to my friend that we can try UREA as a source of "N" to our tank, the problem now was how we can mix a solution of this urea into water.

kh2po4 can easily source out. this is the last one left. we diy the micro also. thank you again.

Bump:


happi said:


> in acid water you can use Urea without any risk, i have used 0.2 to 2 ppm dose in single dose, but there is no benefit of using higher dose more than 0.7 ppm daily in fully planted tank or most of it will convert into NO3. Urea is most beneficial out of all the Nitrogen sources i have tried so far, it can make the plant go wild if used correctly. i would start with 0.5ppm daily without any other source of Nitrogen in the water.


could you please post here or pm me how you mix the urea into water and how much to dose like 5ml per 50 liter of water? any instruction?

this kno3 is really hard to get in Philippines geez. 

thank you,
Roy


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## rmsalaysay (Jan 5, 2016)

OverStocked said:


> Pfertz and RootMedic customers have been adding urea to there aquarium for a very long time with no problems. Ammonical Nitrogen is very rapidly taken up by plants and is preferred by most plants over potassium-nitrogen compounds. Using Urea allows you to up your nitrogen levels in solution that would otherwise be unobtainable, particularly due to potassium solubility. It is popularly used in solutions due to this.
> 
> The "ammonia" in synthetic urea is actually ammonium and is significantly less toxic than ammonia. I've been dosing and testing urea based fertilizers in aquariums for nearly 10 years with no problem.
> 
> ...


may i know how you use the urea and mix and dosing to an aquarium?

i have found that this kind of product is available here in philippines i want to try this to provide "N" in our aquarium.

any comment and suggestion is very welcome.


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## happi (Dec 18, 2009)

rmsalaysay said:


> thank you so much, i have sent a message to my friend that we can try UREA as a source of "N" to our tank, the problem now was how we can mix a solution of this urea into water.
> 
> kh2po4 can easily source out. this is the last one left. we diy the micro also. thank you again.
> 
> ...



James' Planted Tank - Dosing Calculator

use that calc to make urea solution


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## easternlethal (Feb 13, 2016)

how about the urea of a more personal nature?  no need to worry about mixing then...

seriously, for those of us who are thinking about direct dosing CO(NH2)2 is that okay and how frequent should the dosing be? 0.1 - 0.2 ppm per day or say 1-1.5 ppm a week? That would be a heckova lot more efficient than 30ppm NO3.


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