DIY Urea + Ammonia Mix Dosing Chart

[MeganV]

OK, I can see the benefit of having nitrate, but it may well be the urea is doing nothing directly for the corals in your tank.

Correct my summary if its wrong, but less ammonium alone, or less ammonium plus urea both seem to have similar desirable effects, except the nitrate values.

This is the exact conclusion I I am landing on, I think. When I was dosing ammonium alone, I was adding 6x the amount as with the urea. In my mind, the more nitrogen your system is effectively using, the better. The one caveat is I wonder if having a little urea converting to nitrate acts as an emergency "backup" nitrogen pool for interruptions in ammonium availability (say like how glycogen in our muscles fuels us when blood glucose isn't available.)

It does seem like corals struggle in switching back and forth between which type of nitrogen is available.... again, I can relate to this as a human being like when you switch from a keto diet to standard diet with carbs. I sort of see the ammonium as the equivalent of easy to digest carbs for human beings.

All of my observations are purely anecdotal, but I am fascinated by it.

 

[Rhetoric]

Okay, jumping in here with a few questions.

"The story"
Ive been following the Ammonia dosing trend for awhile. I manually does Neo to keep Nitrates barely detectable. Ive decided to finally put it on a dosing pump as "I" am an unreliable manually doser!

Another detail regarding P04 The first 2 1/2 yrs of this tank I added reef roids to make P04 barley detectable. In the last 6 months its rocketed up to .5 (I believe the rock is leaching it back out as I stopped reef roids months ago when it started trending up) I've been using Phosphate E to bring it back down to .1 or less Im not sure this detail matters regarding Ammonia/Neo. Just wanted to paint a fuller Picture.

Months of:
Nitrates @ 0
Phosphate @ .5
Visually I see corals regression.

Current
Nitr @ 0
Pho @ .1

Final detail is I like things to be simple.

Im at a cross road of putting the NEO on the new doser or trying Ammonia bi

Questions:
How long does premixed Ammonia bi last in a storage/dosing container?
Can I mix up enough to dose for 3months or longer?

Would it just be simpler to Neo on the doser?

Finally-
Ive watched countless Ammonia threads and even asked the question. Is Ammonia dosing making a difference? Nobody in this thread says "wow, my corals look so much better"

Anyone weigh in on whether this method is worth it?

 

[Randy Holmes-Farley]

If the container is mostly closed, ammonium bicarbonate solution will be stable quite a while. I refill mine after a couple of weeks.

I dose it because my tank runs a deficit on N.

 

[WhatCouldGoWrong71]

Wish you were here my friend.

- Finally got my nitrate to move up. Thanks for the help :(

@Miami Reef - everything you and I talked about doing is paying off, miss you man. I actually have nutrients that are almost normal. I’m currently holding at 220mil daily (ammonia & urea) into roughly 550g SPS system. It’s a very very high energy system. I’m going to test 3 times a week for a bit, currently doing 1. I’ll set that point of sale Mastertronic to test daily. I’ll see if I can tease a trend out of that white and orange piece of ****. I may need to back it down some if I hit 15-20.

 

[Randy Holmes-Farley]

Good to hear things are working out. :)

 

[ReeferMo]

@Miami Reef - everything you and I talked about doing is paying off, miss you man. I actually have nutrients that are almost normal. I’m currently holding at 220mil daily (ammonia & urea) into roughly 550g SPS system. It’s a very very high energy system. I’m going to test 3 times a week for a bit, currently doing 1. I’ll set that point of sale Mastertronic to test daily. I’ll see if I can tease a trend out of that white and orange piece of ****. I may need to back it down some if I hit 15-20.

he is no longer with us
born on December 21, 1998, in Miami Beach, Florida, passed away on October 24, 2025, at the age of 26.

 

[Dan_P]

he is no longer with us
born on December 21, 1998, in Miami Beach, Florida, passed away on October 24, 2025, at the age of 26.

I discovered this when I was about to PM him a couple days ago to ask where the heck he was hiding but decided to look at the history of his posts. That’s when I saw the announcement that he passed away. What a shame.

 

[bcarl77]

Has anyone experienced a drop in measurable nitrates when starting dosing? Also any loss of color over a long period of dosing. I am dosing only 25ml daily in a 250g nitrates are <10ppm.

 

[obanarama]

Is the consensus now to skip the urea part of this dosing and just dose ammonium? I ask because the first time I dosed Ammonium+Urea it brought my 75g tank's nitrates right up from 2.5 to about 8 so I stopped after 3 small doses of 5mls. That was quickly followed up with a bit of a cyano outbreak, tho I can't say for certain that the ammonium+urea was the reason.

I got the cyano under control and nitrates dropped to about 2~ over the course of a couple of weeks. Then a few of corals seemed to be struggling so I started dosing ammonium+urea again and with each 8ml daily dose the tanks nitrate would rise almost exactly .5. Cool and steady! Nitrates are now up to 6.5, which seems great (phos is .08) - but I now have green film algae on the rocks and glass every day, after a month of it previously being nearly spotless. Can't tell yet if the corals are happier or not yet as its only been two weeks since I started dosing ammonium+urea again.

So should I just keep up the algae scraping and carrying on? Or should I stop the urea part of the dosing?

 

[rishma]

Is the consensus now to skip the urea part of this dosing and just dose ammonium? I ask because the first time I dosed Ammonium+Urea it brought my 75g tank's nitrates right up from 2.5 to about 8 so I stopped after 3 small doses of 5mls. That was quickly followed up with a bit of a cyano outbreak, tho I can't say for certain that the ammonium+urea was the reason.

I got the cyano under control and nitrates dropped to about 2~ over the course of a couple of weeks. Then a few of corals seemed to be struggling so I started dosing ammonium+urea again and with each 8ml daily dose the tanks nitrate would rise almost exactly .5. Cool and steady! Nitrates are now up to 6.5, which seems great (phos is .08) - but I now have green film algae on the rocks and glass every day, after a month of it previously being nearly spotless. Can't tell yet if the corals are happier or not yet as its only been two weeks since I started dosing ammonium+urea again.

So should I just keep up the algae scraping and carrying on? Or should I stop the urea part of the dosing?

I am sure there is no consensus. The only thing we all agree on is reefs need water.

I’ve been dosing for a few months. I also notice the quick nitrate contribution compared to straight ammonium bicarbonate. I have had no negative results. Corals respond similar to ammonium bicarbonate.

 

[obanarama]

I am sure there is no consensus. The only thing we all agree on is reefs need water.

I’ve been dosing for a few months. I also notice the quick nitrate contribution compared to straight ammonium bicarbonate. I have had no negative results. Corals respond similar to ammonium bicarbonate.

Ha! Good point, I'll strike consensus from my reefing vocabulary. And thank you for the feedback.

 

[bcarl77]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

 

[rishma]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

How’s your phosphate? Trace elements?

 

[EnterName]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

I don't think it is the ammonia (or urea), but there might be side effects caused by adding nitrogen to the system:

Carbon, nitrogen, and phosphate are nearly always consumed in some more or less fixed ratio (the ratio depends on algae, coral, bacteria, etc.). Dosing ammonia or nitrate to a nitrogen-limited tank can therefore increase carbon and phosphate uptake and cause other limitations (which might cause color loss).

Additionally the uptake of nutrients relies on the biosynthesis of certain enzymes that use trace elements like iron. If you are not providing enough of these trace elements for the increased nutrient uptake this might cause deficiencies and color loss, as well.

Of course this is purely hypothetical because I don't know anything about your tank and water parameters, but I'm sure the community will be able to help you if you open a separate thread :)

 

[bcarl77]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

How’s your phosphate? Trace elements?

I run reef moonshine method. Traces are generally in line. Phosphate has been slightly elevated 0.2ppm but got them back down to ~0.1ppm.

 

[rishma]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

How’s your phosphate? Trace elements?

I run reef moonshine method. Traces are generally in line. Phosphate has been slightly elevated 0.2ppm but got them back down to ~0.1ppm.

Interesting. I cannot guess why colors would pale. I observed the opposite with more ammonia seeming to increase zooxanthellae or pigment and the colors darkening.

 

[bcarl77]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

How’s your phosphate? Trace elements?

I run reef moonshine method. Traces are generally in line. Phosphate has been slightly elevated 0.2ppm but got them back down to ~0.1ppm.

Interesting. I cannot guess why colors would pale. I observed the opposite with more ammonia seeming to increase zooxanthellae or pigment and the colors darkening.

I don’t disagree with that logic. When I initially started dosing I had some form of dinos and nitrates where around 20. I actually observed the nitrate drop when I started dinos disappeared and so the general colors.

 

[rishma]

Has only seen impacts of long term dosing in terms of coral coloration? I have been dosing for a while holding nitrates around 10ppm and observed significant color loss.

How’s your phosphate? Trace elements?

I run reef moonshine method. Traces are generally in line. Phosphate has been slightly elevated 0.2ppm but got them back down to ~0.1ppm.

Interesting. I cannot guess why colors would pale. I observed the opposite with more ammonia seeming to increase zooxanthellae or pigment and the colors darkening.

I don’t disagree with that logic. When I initially started dosing I had some form of dinos and nitrates where around 20. I actually observed the nitrate drop when I started dinos disappeared and so the general colors.

I think most people that dose have chronically low nitrate as a way to ensure the corals get enough nitrogen. You started when you already had a good amount of nitrate. What made you start dosing?

 

[bcarl77]

I was pretty confident what I was dealing with was dinos and thought I read somewhere that it could be a possible solution. Then after the dinos cleared it was under 10ppm so I kept dosing.

 

[bcarl77]

One note on my experience here. I stopped dosing around new years. My nitrates when from ~5ppm down to 0 over the course of 2 weeks. Some corals got ticked and saw some tissue recession so I restarted dosing. I did not notice and changes in color. I am going to now try to get my nitrates over 10 with the urea+ammonia and see if I have any discernible changes.