DIY Urea + Ammonia Mix Dosing Chart

[Miami Reef]

It appears many users are noticing benefits by dosing Urea + Ammonia to their reef tanks. Both increase useable nitrogen and nitrate in reef tanks for corals to consume.

I believe this is the original article that informed users of the potential benefits of urea dosing. This chart emulates the same stock solution and recipe as it.

The DON/DIN Rabbit Hole - Urea Dosing And A New ...​

The recipe:

20g of ammonia bicarbonate + 5 g of urea mixed in one liter (L) of water.

You can purchase ammonium bicarbonate here:

Amazon.com

I will link a few sources of urea that one can purchase for reef tanks:

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Amazon.com : Urea [CH4N2O] 99+% ACS Grade Prills 6 Oz in a Space-Saver Bottle : Beauty & Personal Care

Amazon.com : Urea [CH4N2O] 99+% ACS Grade Prills 6 Oz in a Space-Saver Bottle : Beauty & Personal Care

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The chart shows the amount of urea and ammonia added in ppm per dose, along with the corresponding nitrate equivalents

 

[RoanokeReef]

This is what I currently use, up to 35ml in a 69 and still can't get a reading above 0 on Hanna Test or Trident. Do I keep going up? Corals look great.

 

[Miami Reef]

This is what I currently use, up to 35ml in a 69 and still can't get a reading above 0 on Hanna Test or Trident. Do I keep going up? Corals look great.

If nitrate is at 0 ppm, you can definitely increase the dose. Some tanks just have an above-average nitrogen demand.

 

[Randy Holmes-Farley]

This is what I currently use, up to 35ml in a 69 and still can't get a reading above 0 on Hanna Test or Trident. Do I keep going up? Corals look great.

If corals look great, stopping is fine, or you can raise it as an experiment and if things begin to look less great, you can back off to this level. :)

 

[BriDroid]

If corals look great, stopping is fine, or you can raise it as an experiment and if things begin to look less great, you can back off to this level. :)

That would be my suggestion as well. When I dosed ammonium bicarbonate heavily trying to get readable NO3, my corals became less colorful. With this ammonium/urea combo, I can dose a much smaller amount, corals look great, and I can keep readable NO3 in the system.

 

[rishma]

I have no excuses now that you did the math for us

 

[Red_Beard]

Thanks for this @Miami Reef :)

 

[Miami Reef]

This is for the math nerds.

 

[Randy Holmes-Farley]

This is a freshwater article, but as more folks experiment with urea, it will be interesting to see if any get problem cyano:

Urea Is Both a Carbon and Nitrogen Source for Microcystis aeruginosa: Tracking 13C Incorporation at Bloom pH Conditions - PMC

The use of urea as a nitrogenous fertilizer has increased over the past two decades, with urea itself being readily detected at high concentrations in many lakes. Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen ...

pmc.ncbi.nlm.nih.gov

"Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen (N) - source for cyanobacteria that possess the enzyme urease. "

 

[Red_Beard]

This is a freshwater article, but as more folks experiment with urea, it will be interesting to see if any get problem cyano:

Urea Is Both a Carbon and Nitrogen Source for Microcystis aeruginosa: Tracking 13C Incorporation at Bloom pH Conditions - PMC

The use of urea as a nitrogenous fertilizer has increased over the past two decades, with urea itself being readily detected at high concentrations in many lakes. Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen ...

pmc.ncbi.nlm.nih.gov

"Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen (N) - source for cyanobacteria that possess the enzyme urease. "

Yes. I would suggest this possibility. Although this was, in this case, fairly manageable and cleared after a month or two.

 

[Austinsdepenbrock]

Bump

 

[BriDroid]

Yes. I would suggest this possibility. Although this was, in this case, fairly manageable and cleared after a month or two.

I had a little pop up when I first added the urea. I used my normal Microbacter 7 and Clean dosage and it went away on its own.

 

[rishma]

Since I have a tiny tank and dose small amounts I am wondering about the decomposition of the urea in my solution. It will sit a long time. Since it’s mixed with ammonia, which is a product when the urea decomposes, would that slow the decomposition?

 

[Miami Reef]

Since I have a tiny tank and dose small amounts I am wondering about the decomposition of the urea in my solution. It will sit a long time. Since it’s mixed with ammonia, which is a product when the urea decomposes, would that slow the decomposition?

At pH 6 or higher, the half life is more than a month. The hydrolysis products appear to be ammonia and CO2. Thus, combining urea with ammonium bicarbonate appears to not be a problem unless one wants to store it a long time..

https://journal.uctm.edu/node/j2019-2/9_18-196_p319-325.pdf

^

 

[BriDroid]

Since I have a tiny tank and dose small amounts I am wondering about the decomposition of the urea in my solution. It will sit a long time. Since it’s mixed with ammonia, which is a product when the urea decomposes, would that slow the decomposition?

I recently changed my dosing pump and needed to dose larger quantities into my nano. I divided the recipe by 10, and made 250ml. Dosing 10ml a day, mine will now last 25 days. It seems to be working fine so far, NO3 is holding on the new dose.

 

[rishma]

Since I have a tiny tank and dose small amounts I am wondering about the decomposition of the urea in my solution. It will sit a long time. Since it’s mixed with ammonia, which is a product when the urea decomposes, would that slow the decomposition?

At pH 6 or higher, the half life is more than a month. The hydrolysis products appear to be ammonia and CO2. Thus, combining urea with ammonium bicarbonate appears to not be a problem unless one wants to store it a long time..

https://journal.uctm.edu/node/j2019-2/9_18-196_p319-325.pdf

^

Thanks. I read the paper and I didn’t quite answer my question. Since the decomposition of urea produces ammonia carbonates and the solution I added urea to already has ammonia carbonates, I wonder if it slows the decomposition.

Perhaps not in a material way since the solubility of ammonium bicarbonate is really high and the concentration of the stock solution is quite low.

 

[Randy Holmes-Farley]

I

Since I have a tiny tank and dose small amounts I am wondering about the decomposition of the urea in my solution. It will sit a long time. Since it’s mixed with ammonia, which is a product when the urea decomposes, would that slow the decomposition?

I would not assume ammonia will slow it, but pH has a big effect. Best to have the pH close to neutral.

 

[TangingOut]

I just tried making this solution and found the urea very difficult to dissolve at room temp. Had to heat up the water and even then had a lot of particulates float to the top. Any all all advice welcomed

 

[BriDroid]

I just tried making this solution and found the urea very difficult to dissolve at room temp. Had to heat up the water and even then had a lot of particulates float to the top. Any all all advice welcomed

Weird! Mine dissolves pretty easily. I use a magnetic stirrer and dissolve the ammonium bicarbonate first then add the urea. It is usually dissolved in 5 to 10 minutes at room temperature.

 

[TangingOut]

I bought this one and the granulars were pink and semi moist. I now notice other products are white/crystal from product pictures

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