urea as a substitute for KNO3?

[jinhui]

Hi all,

Can urea be used as a substitute for KNO3?

Or can is there a need for me to dose CaNO3 (dry form) as a substitute for KNO3?

As it is illegal to get KNO3 in Singapore.

And can i follow the EI dosing guideline using urea or CaNO3?

 

[Tom Barr]

As long as you add enough K2SO4(eg GH booster has a lot), Ca(NO3)2 works fine. Also, Dr Mallick's sells KNO3 for aquarist. Aquaticquotient.com has plenty of locals that can direct you to where to buy KNO3 locally or alternatives.

 

[jinhui]

Hi Tom,

I've given Dr. Mallick a called and he told me the same thing. but he can sell me KNO3 in liquid form which is 11% KNO3 (much more expensive).

That's why i am looking for a cheaper alternative like CaNO3 (dry form).

Thanks for the answer regarding CaNO3.

what about Urea?

I've read about people using Urea to produce more growth in plants and it's ammonia which is taken up by the plants more readily than NO3.

Can it be used as an alternate form of nitrogen fertilizer?

 

[UDGags]

I did a Google search and found these slides. Slide 4 has the hydrolysis of Urea, which is what would happen when we would put it in an aquarium. You will get NH3 so you need to be careful about fish and inverts and even overdosing your plants.

Here was some discussion about it on various boards....
http://www.aquaticplantcentral.com/forumapc/fertilizing/78509-urea-fertilizers-aquatic-plants-3.html
http://www.plantedtank.net/forums/showthread.php?t=131223

 

[Tom Barr]

You cannot add urea like KNO3, go with Ca(NO3)2.

 

[Petex]

Like Tom said, using just only urea isn´t mostly any good idea - because you can not dose it that much.
Most ppl. still dose 0,1- 0,2ppm urea as small addition and together with other nitrate sources.
In one high light tank I dose ~0,5ppm urea as addition, but I don´t keep any sensitive animals there and never meassured anything.
There may be some nitrite/ammonia spices for short time, but i dont know how much or high at last.
So certainly for any sensitive animals this may be harmfull (depending on PH and other things) and doing so not recommended.

Depending on yours tap, you may better go with a mix:
Ca(NO3)2 and Mg(NO3)2x6H20

 

[jinhui]

Oh ok. thanks Tom, UDGags and Petex.