urea and it's bad aspects-please debate

[djs-sa]

urea

[Jonathan Dyer]

Yes, over the past 5 years its price has increased 300%.

[Outbackozzie]

hehe

1. Very Powerful in small AP systems.
2. Has traces of heavy metals.

Apart from that its all good? I am actually planning on running my quarantine system solely on urea and seasol once the current tennants are evicted, then maybe send some plant tissue off to be analyzed for toxicity.

[GaryD]

Used properly, it's a good ammonia source that is very effective for use in fishless cycling.

[Murray]

Likewise DaveO,
I have not ever had a problem cycling a system by just adding the fish straight up.
Starting out with some water from another system really helps.
A large volume of water helps. Most that I have read about fish less cycling a system comes from the aquarium industry where (evidently) cycling is a bit of an issue. I feel that this may be the case because of the much smaller volumes of water in circulation and their filters are very small by comparison to gravel grow beds.
I have just tried fish less cycling on a new system I have just built.
During the three weeks I was adding one teaspoon of UREA a day (1250 ltr tank and 2 x 400 ltr grow beds) and one cap full of Seasol.
The Ammonia readings were very small if at all at any time during this process.

I should move this to another thread about UREA.
I added the 150 jade perch which are around 10 weeks old. Stopped the UREA one day before adding the fish.
All is rocking along well, except that most of the plants which did exceptionally well in the first 3 weeks are now exhibiting classic leaf burn from too much UREA.
Now, I am not a scientist, so I cannot be 100% sure about the cause of the burnt leaves, but I have seen the same effect in a regular garden when there was too much fertiliser added.
The Ammonia before and since I have added the fish is difficult to detect, if there is any there at all.
I do not wish to go against others who like to fish less cycle, but I would never try using UREA again.
I am not comfortable with whatever else may be in the UREA. It just goes against the principals of doing away with as much artificial material as possible in ones food supply.
Why are my plants suffering leaf burn ?
The 1 teaspoon a day is well below the amount of UREA I have seen recommended, for fish less cycling, but that amount applied to a regular garden of the same size as my 2 x grow beds would almost certainly suffer leaf burn and even death of plants.
Perhaps it would not have mattered in my new system if there were no plants.

[GaryD]

Hi,

You can find the Materials Safety Data Sheet for Yates Urea......here.

I can't find any mention of heavy metals or other contaminants in urea....but I'll keep looking. I recommend the use of urea based on my perception that it is a clean nitrogen source.

Gary

[Dufflight]

I think that data sheet is more for safety and handling. Just says its 100% urea, not what makes up urea. Be nice to find a pure form that does not have any metals but it could be a byproduct of its production.

[Jonty]

Urea is made commercially from two raw materials, ammonia, and carbon dioxide. It is also used as a non-protein nitrogen source in ruminant feed and it is converted into protein in the gut. O heavy metals at all.
Regards
Jonty

[Dufflight]

Its in the fine print

[Jason Palenske]

Its in the fine print

Well I don't know what your water rules are, but with maybe the exception of the lead, that may be on par with what is in normal city tap water.