OK, since I am here and onto "controversial" subjects ...

JohnSmith

JohnSmith

Registered Member
Oct 4, 2008
134
0
0
74
UREA => ammonia => nitrites => nitrates ... end of story (or so my 'education' on the nitrogen cycle goes)

So, I have (last couple of months) began substitution of Urea for Potassium Nitrate. I think, I have better growth of plants (not to mention I bought an 80 pound sack of this from the local ag chem distributor--think BIG TIME farming here) From time-to-time, I do notice a small spike in ammonia (usually 0.05 or below), which is quickly 'absorbed' by the tank ...

Has anyone else used urea in a planted/algae-ridden tank with good success and no, seeming, distress of fish/tank-inhabitants?

I seem to notice that plants GREATLY prefer the Urea to Potassium Nitrate, and they 'speak' this by their accelerated growth ...

Regards,
JS
 
I suspect that Urea is less popular because of the NH3 spiking issue. Not only does KNO3 avoid this, it supplements K, another important component in the plant feeding system.

Also - KNO3 is not exactly "expensive" either.
 
going on what squawkbert said... with the risk of NH3 spiking it would quite possibly require increased care and diligence in dosing. Speaking personally that is something that doesn't appeal to me if there is a suitable alternative (KNO3).
 
Sounds like a good alternative. It has potentially two downsides: 1) The NH3 spike but in a heavily planted aquarium it's doubtful this would be an issue 2)Availability of smaller quantities. Sure, it's dirt cheap, so's KNO3, but a lot of people don't want to keep a 50 lb bag sitting around considering most people *might* use 1 lb. a year

However, that last one is really not a major concern since it would only take one person to start buying the big bags and repackaging it like Rex or AquariumFertilizer.com do.

You see no harm posed to fish? I've never used Urea, so I'm curious.
 
Urea is certainly less toxic than straight ammonia (which is why we mammals convert our ammonia to urea in the first place), so I can't see it being an issue unless you are adding enough to see a big ammonia spike.

Fun fact: Urea was the first organic compound to be successfully synthesized, thus disproving the hypothesis that organic compounds could only be created by living organisms.
 
Has anyone else used urea in a planted/algae-ridden tank with good success and no, seeming, distress of fish/tank-inhabitants?

I seem to notice that plants GREATLY prefer the Urea to Potassium Nitrate, and they 'speak' this by their accelerated growth ...
Click to expand...

So in your experience you have not noticed any distress?

Bacteria, with the help of the enzyme urease, can readily degrade urea according to the following schemes:
• H2NCON2H (urea) + 2H2O => 2NH4 + HCO3
• NH4+ => NH3 (g) H+
• HCO3 + H+ => CO2 (g) + H2O
Ammonia (NH3) can further oxidize to nitrate (NO3).

The biodegradation of urea to the end products of CO2 and NH3 requires, in theory, the consumption of 0.27 mg of oxygen per mg of urea. If the NH3 further decomposes to nitrate (NO3) the theoretical oxygen demand (TBOD) increases to 1.87 mg O2/mg of urea.
 
You must log in or register to reply here.
AquariaCentral.com
Top Bottom