# UREA to NO3



## Lonew0lf (20 May 2017)

All,

I'm currently using an all in one EI solution called Thrive.  Per Thrive's instructions, 6ml/week delivers the follow:

N - 21
P - 3.99
K - 15

I've been slowing introducing UREA CO(NH2)2 to the mix.  I'm dosing 1/8th teaspoon into 50ml of water giving me ~.30ppm for each 1ml.  I started the week at .5ml and slowly working up to 1ml.  I've taken this approach to see how the plants and fish/shrimp respond.

This steady as she goes approach has worked well so far.  As a side note, I also have MGS04 in the UREA solution.  This is pressured CO2 45p tank w/ Par @ 115 surface / 55 substrate.

What I'm unsure about is how much .30ppm translates into N and finally NO3.  I've checked a few forums and reached out the the maker of Thrive but don't have a conclusive answer.  Any assistance would be appreciated.




 

Thanks in advance
LW0lf


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## Lonew0lf (21 May 2017)

I was able to get some additional data from the makers of Thrive (approximations):

.75 urea = 1.5ppm N = 7ppm NO3

I also calculated UREA dosing using Nuno's Crystal Mountain calculation sheets using his gram breakdown:

https://www.ukaps.org/forum/threads/crystal-mountain.42683/page-7

Of course I get conflicting information... the green shaded area is is Nuno's and the pink is Thrive's.  Can anyone point me in the right direction


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## dw1305 (21 May 2017)

Hi all,
It won't be exact, because the urea will be converted to <"two ammonia molecules"> (NH3) via organisms with the urease enzyme, but you can use their respective nitrogen (N) contents.

Urea has an RMM of 60 and has two nitrogen (N) atoms, and N has an RAM of 14. Twenty-eight divided by sixty makes urea 47% N.
Nitrate (NO3) has an RMM of 62, one N atom and is 22.7% N.

So one gram of urea is equivalent to approximately half gram of nitrogen or two grams of nitrate.

cheers Darrel


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## Lonew0lf (22 May 2017)

Darrel,

Thanks for the input... assuming I did this correctly... .

15ppm UREA =

N: .075
NO3: .3
If that's correct I'm really not dosing that much CO(NH2)2 at all; ~ an extra 3ppm per week.


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## dw1305 (22 May 2017)

Hi all,





Lonew0lf said:


> 15ppm UREA =
> 
> N: .075
> NO3: .3


No, 15ppm urea would give you ~7ppm N (15*0.47) or ~ 32ppm NO3 (7/0.22).

cheers Darrel


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## Lonew0lf (22 May 2017)

Apologies, typed my previous note quickly... my daily dose is .15ppm not 15ppm...

But your above calcs help.

Thank you.


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## dw1305 (22 May 2017)

Hi all,





Lonew0lf said:


> Apologies, typed my previous note quickly... my daily dose is .15ppm not 15ppm...


Yes that would make sense.

cheers Darrel


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## roadmaster (22 May 2017)

Articles on ammonia/urea excretion across the gill's of fishes were an interesting read for me.(are several out there)
I might would be tempted to just add more fishes rather than come up with precise amount of urea I could safely add on top of that created by fauna.?


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## Lonew0lf (22 May 2017)

Roadmaster –

You make a great point about fish health and it’s something I’ve considered and the primary reason I’m dipping my toe slowly into the UREA dosing approach.

After adjusting the lights down for the level of CO2 (unknown variable), I’ve got good growth and no algae.  With a stable tank, I’m comfortable introducing UREA to see whether I can optimize fertilization and get any additional benefits without increasing CO2 or running lights at higher Par levels.

I’m targeting the inputs that are easier to quantify: light (Par level) and fertilizer (EI).  I’ve ditched the bubble counter & drop checker, relying only on fish response; unfortunately it’s a poor way to measure CO2 levels (but so was a drop checker or bubble counter); but at least I have a sense for what the fish can tolerate.

Adding more fish is an option but I can’t easily measure what amount of NH4 is being introduced to the tank from additional feeding, etc.

We have the tools and to the extent I can test some inputs, why not try.


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## roadmaster (23 May 2017)

I understand.
I use a popular plant fertilizer spike /stick for terrestrial plant's under the base of a couple large echinodorus , and the plant spikes contain urea along with nitrogen and po4.(Miracle Grow plant food spikes)
I only add one under each plant, and replace them about once a month or every other month.
I push em deep as I can and have seen no adverse effect on fishes,shrimp's, but tank volume is a significant player.
I might only use half a plant spike in smaller volume of water.
Also have fairly large plant mass.
Directions for the plant spikes indicate maybe two or three of these plant spikes under each plant according to size but I do not wish to push my luck with fauna.
I suspect the release of the fertz/urea to be accelerated in submerged condition's as opposed to dirt in flower pot.


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## DanielC03 (23 May 2017)

What advantages do you see in replacing NO3 with Urea?


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## Lonew0lf (23 May 2017)

DanielCO3,

It's a supplement to the KNO3 from my the all-in-one ferts. 

The idea of providing plants with another source of Nitrogen is interesting to see if it has an impact. 

Others have hinted at dosing during the photo period to ensure the plants can benefit rather than the UREA being consumed by the biological filter.


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