First let me state this is not a joke and I'm not trying to be funny. This is purely scientific. On the History channel they were showing how they use human waste as fertilizer for golf courses. It said urine contains Nitrogen, Phosphate, and Potassium. Upon further reading I came across that gardener's dilute their urine to 10 to 20 parts water: 1 part urine for plants. Obviously fish produce NPK from their waste as well but they don't produce enough which is why we dose with ferts. Instead of dosing with ferts, why couldn't we dose with urine? I posted this on TPT but it got shut down by a moderator that couldn't take it seriously. I got PM's from people requesting for the thread to be reopened so I've brought the idea here.

Hey there. I'm no expert but one of the main reasons might be that urine has some ammonia content which is very bad for a tank because it will trigger and algae bloom (Also it isn't good for the fish). A quick google search led me to this page:

The Skeptical Aquarist

To quote from the page: "Urine has a specific gravity of about 1.017-1.020, owing to its dissolved solids, about 60% of which are organic substances. Besides ammonia, those organics include urea, uric acid, and creatine, which are all bacterially decomposed to form carbon dioxide--— and more ammonia."

So it seems like there is a good chance that all the ammonia created/added from the urine will hurt the fish and also give rise to an algae bloom.

I might be wrong or there might be other reasons. This is what seemed to make the most sense to me. Btw, I'm surprised that your thread got locked at TPT! That seems rather silly.

Well since you are diluting the urine the ammonia should be in very low concentrations. In a cycled tank the ammonia should be instantly converted to nitrates which is good since plants need them. Plus if it really worries you you could detoxify it with Prime. You also said it converts to carbon dioxide which would really help in low-tech tanks.

This idea has come up before on other forums, and I still can't see an advantage to using urine instead of KNO3. There are certainly disadvantages, including the fact that only in a healthy person could urine not contain potentially harmful compounds. Even then, I believe it contains a lot of sodium. (I haven't googled to see if that is true yet.)

It's free and convenient. Why pay $20 when you can get it free in seconds.

Have you smelled your urine lately??? Do you want your aquarium smelling like a out house? You can get a pound of KNO3 for three bucks which will last you well more than a year. Save yourself the self pity of canning up your urine and then feeding it to your tank.

Shop online at AquariumFertilizer.com

What about for ponds? It may be a little more suited for the outdoors. And with such an easy dosing method who wouldn't try it . Nature's Calling!!!

It is already common practice for ponds. At least in my experience as a youth in rural Missouri that was the case. You wouldn't believe the great tasting fish and bullfrogs we used to catch in those ponds!

There was an old thread many years ago on the APD about using cat litter as a sediment, and then seeing if you get the cat to do it's duty in the tank to fertilize the plants via the water column.

Some serious, some not.

Golf course, well, I not too supportive of that.
But the need to do something with all the wastewater is a big issue and to do it cheaply.

Folks have long used manures, and compost for sediment ferts.
Water column ferts are bit more troublesome when it comes to more organic methods.

However, if you are really into the organic methods, why not simply have plenty of fish and feed them only organic foods? Then do not add CO2 gas, go non CO2?

Fish excrete urine via the gills.

Regards,
Tom Barr

A big problem is that human urine actually contains very little ammonia (hence it should burn when you pee) compared to a concentrated source like KNO3. And KNO3 is a known value. Unless you test your urine each time you are dosing blindly. And human urine contains a lot of waste that you frnakly don't want in your tank. Take a multi vitamin? Well a lot of that goes into urine. Take birth control? In the urine. Human hormones? In the urine etc.... Just too many variables. Garden plants get rained on and you are dealing striclty with plants. In the tank you are dealing with fish that will be dealing with your waste products.

Buying relatively pure hydroponic grade ferts seems so much easier and safer to me.