Backyard Aquaponics
A place to discuss aquaponics

Found a place in the next town for silvers, $1 each. None till Nov. Going to go over on monday and get a 100 blue yabbies. Got a bag of urea, anyone notice the lead that is in that stuff.

No lead in mine!! I wouldnt use it if it has lead. Mine is nitrogen biuret I think

Mine is the 40kg bags they use on farms. Maybe they don't list everything on smaller bags for the domestic market? Will have another look at the ppm per kg.

I will check mine out tomorrow

Had a google and mercury and lead is listed in some of the links to biuret urea, but harder to get a link on the amounts. One link listed them as a catalyst in urea?? Another wanted a username and password to get more information on lead in products. My guess that for domestic use they don't need to list it if its only trace amount but with growing for human consumption they have to list everything. Even in a sealed system like AP the amounts might be just trace unless you add on a regular basis.

No more dry urea in the system for me then, I will use it on the grass

Hell I got 40kg and I don't like mowing the grass now. Remember when I moved years ago I got rid of all my powdered fert by throwing it over the back yard. It killed the grass but the next guy that lived there complained about having to mow the grass every 4 days in summer.

This link .....,http://www.gilgames.com.au/ureaspec.html
States 100 % free of harmfull sunstances.

Just a reminder with urea or fresh humonia, there is a lag time from addition to the system and conversion into ammonia so one needs to be careful not to overdose when the ammonia readings don't show up by the next morning.
I was able to cycle a 600 gallon (2271 L) system with less than 400 ml of aged humonia per day (was more like every other day with less than 500 ml per dose.) For a person that drinks lots of water, this could probably work out to one big pee per day.

I'm still trying to work out what I need for mine. 55kl is a lot of water.

Maybe that does not count Impurities

Well, how much for 55KL, that is about 25 times as much water so the initial dose probably needs to be pretty high to get much of an ammonia reading. Lets see, If I were going to try and cycle up that large a system, I would probably start with a reasonably large dose of between 5 and 10 liters. (This could be tricky if you haven't been saving it.) After that, I would probably drop back to adding less than that. The amount would vary depending on how many fish I was planing to put in the system at the start. If you are going to start out with say 100 small fish, and you only have a limited amount of grow bed volume, you could drop back to the 400-500 ml or less per day. The 600 gallon system I cycled with the 400 ml of humonia per day had around 450 gallons of gravel at the time of initial cycling. If you are only going to have about 8 blue barrels worth of gravel, then after initially getting the ammonia concentration up to 1-2 ppm, you will likely never need a huge dose of hummonia again. You will just need enough to keep feeding the bacteria growing in the gravel until you get fish.

Sounds like a lot of "pee" is needed,,, being the helpfull person I am ,, you supply the beer and I guarrantee to supply the pee.

Am is .25 to .50
I'm also adding water from the smaller system when I do changes to keep its Am down.

Which system is reading between .25 and .5 ppm ammonia?