Help. Can’t get Nitrite <200ppb

[cutter2001]

Hey guys. Noob here. I have a new Red Sea G2 Nano XL tank that started a fishless cycle on 01/23/26. Ammonia peaked at >2.5ppm with Nitrite initially registering at 11.2ppb on 01/25/26. Fast forward to today. Ammonia is .06 with Nitrite >200ppb after two 60% water changes. Last ph was 8.1. I continue to add Mycobacter-7. Latest Nitrite test after water changes tonight with Hanna blue box lab >200ppb. What am I doing wrong?

 

[JTP424]

Are you seeing any Nitrates appearing?
Is Microbacter the only thing you used to "consume" the ammonia?
Or did you use something like Turbostart/Tims etc.

 

[JTP424]

Additionally a water change will slow down your cycle.

 

[cutter2001]

Are you seeing any Nitrates appearing?
Is Microbacter the only thing you used to "consume" the ammonia?
Or did you use something like Turbostart/Tims etc.

Started off with 4oz. of Dr. Tim’s All in One to start.

Nitrates: 28.1

 

[Lasse]

https://www.reef2reef.com/threads/d...n-how-when-should-my-levels-worry-me.1145465/
and

https://www.reef2reef.com/threads/n...-equal-whos-who-and-what-do-they-need.989780/
Sincerely Lasse

 

[Fish Fan]

Hey guys. Noob here. I have a new Red Sea G2 Nano XL tank that started a fishless cycle on 01/23/26. Ammonia peaked at >2.5ppm with Nitrite initially registering at 11.2ppb on 01/25/26. Fast forward to today. Ammonia is .06 with Nitrite >200ppb after two 60% water changes. Last ph was 8.1. I continue to add Mycobacter-7. Latest Nitrite test after water changes tonight with Hanna blue box lab >200ppb. What am I doing wrong?

You're not doing anything wrong, and there's zero to be concerned with here, in my opinion. 200 ppb (0.20 ppm) nitrite is a very low concentration, and nitrite isn't important in marine aquaria, you don't really have to test for it at all.

Looks to me like the ammonia started off high and is now coming down, and nitrite is beginning to accumulate, which is to be expected. Have you checked for nitrate yet?

As mentioned, I would discontinue water changes at this point, it's counter effective when initially cycling a tank. I would suggest just giving your cycle some more time to do its thing

Good luck!

 

[cutter2001]

Hey guys. Noob here. I have a new Red Sea G2 Nano XL tank that started a fishless cycle on 01/23/26. Ammonia peaked at >2.5ppm with Nitrite initially registering at 11.2ppb on 01/25/26. Fast forward to today. Ammonia is .06 with Nitrite >200ppb after two 60% water changes. Last ph was 8.1. I continue to add Mycobacter-7. Latest Nitrite test after water changes tonight with Hanna blue box lab >200ppb. What am I doing wrong?

You're not doing anything wrong, and there's zero to be concerned with here, in my opinion. 200 ppm nitrite is almost nothing, and nitrite isn't important in marine aquaria, you don't really have to test for it.

Looks to me like you're ammonia started off high, and is now coming down, and you're nitrites are beginning to accumulate, which is to be expected.

As mentioned, I would discontinue water changes at this point, it's counter effective when initially cycling a tank. I would suggest just giving your cycle some more time

Good luck!

Should I add more bacteria to off set what I may have lost in the water changes? When can I add livestock to the aquarium if nitrite is nothing to worry about?

 

[cutter2001]

https://www.reef2reef.com/threads/d...n-how-when-should-my-levels-worry-me.1145465/
and

https://www.reef2reef.com/threads/n...-equal-whos-who-and-what-do-they-need.989780/
Sincerely Lasse

Thank you. Excellent posts. I’m still confused as to whether nitrite in a salt water aquarium environment is toxic to fish and corals. Seems some sauces, others don’t even test for it.

 

[Randy Holmes-Farley Verified Community Expert]

Thank you. Excellent posts. I’m still confused as to whether nitrite in a salt water aquarium environment is toxic to fish and corals. Seems some sauces, others don’t even test for it.

Don’t be confused. IT NEVER is toxic in a reef tank. Real studies show it takes hundreds of ppm to kill marine fish. You measured a thousand times less than that.

 

[Fish Fan]

Should I add more bacteria to off set what I may have lost in the water changes? When can I add livestock to the aquarium if nitrite is nothing to worry about?

You can start to slowly stock with some hardly livestock once the ammonia goes down to nearly zero.

I don't personally think you need to add any more bacteria, I would just let what you have grow. They mostly populate on the rocks, sand, and other surfaces, so doing water changes doesn't remove a significant portion of the beneficial bacteria.

 

[Lasse]

Acute toxicity - IMO - none but for me - NO2 above 0.1 - 0.2 ppm indicate a disturbed bacteria system.

In opposite to Fish fan - I think that you have add wrong bacteria species and if you want to have down the NO2 - you ma have to add bacteria of the right type. The ones in red!

But its not toxic as it is now.

Here is another article

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

I have no doubt an inadequate or disturbed bacteria system can increase nitrite. It likely increases a lot of other things as well. But folks should not confuse that with it being a concern unless something reaches its toxic concentration. :)

 

[56longroof]

Should I add more bacteria to off set what I may have lost in the water changes? When can I add livestock to the aquarium if nitrite is nothing to worry about?

Bacteria mostly colonizes on the rocks and substrate. I doubt you lost any significant amount with water changes.

 

[Lasse]

I have no doubt an inadequate or disturbed bacteria system can increase nitrite. It likely increases a lot of other things as well. But folks should not confuse that with it being a concern unless something reaches its toxic concentration. :)

My italic and bold. Its not toxic as we know it - its true - but my largest concern when starting a new aquarium is not - not toxic - put in fish - they will survive. My concern is to start an aquarium that create as low as possible problems during its life time. IMO - a healthy. stable and diverse bacteria population is the the cornerstone for a successful aquarium in the long run and the first and easiest bacteria system to establish is IME the nitrification process. Today we know how to do that - and which additives work well to establish both stages of nitrification.

That it doesn't kill is one thing - but I am convinced that a well-functioning and established nitrification process as early as possible is the cornerstone of a well-functioning aquarium in the long run.

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

My italic and bold. Its not toxic as we know it - its true - but my largest concern when starting a new aquarium is not - not toxic - put in fish - they will survive. My concern is to start an aquarium that create as low as possible problems during its life time. IMO - a healthy. stable and diverse bacteria population is the the cornerstone for a successful aquarium in the long run and the first and easiest bacteria system to establish is IME the nitrification process. Today we know how to do that - and which additives work well to establish both stages of nitrification.

That it doesn't kill is one thing - but I am convinced that a well-functioning and established nitrification process as early as possible is the cornerstone of a well-functioning aquarium in the long run.

Sincerely Lasse

OK, I can see that point, though I do not think I have ever seen an established reef tank that could not process ammonia unless something new happened to it.

I also think that if nitrite were not vastly more toxic in freshwater systems, almost no one would be measuring it or worrying about it.

There are plenty of toxins in reef tanks that are real problems in real tanks. Folks should redirect their nitrite concerns to them. Some inorganics such as tin and aluminum and zinc, as well as lots of organic toxins from cyano, dinos, and lots of other organisms that want to kill competitors or predators.

 

[Lasse]

OK, I can see that point, though I do not think I have ever seen an established reef tank that could not process ammonia unless something new happened to it.

Maybe not - but in this case - and most case with high NO2 concentrations - is it new tanks and IMO - as I said before - a tank there the nitrification process is established early - before to much organic load - may be easier to handle in the future


Sincerely Lasse

 

[cutter2001]

Acute toxicity - IMO - none but for me - NO2 above 0.1 - 0.2 ppm indicate a disturbed bacteria system.

In opposite to Fish fan - I think that you have add wrong bacteria species and if you want to have down the NO2 - you ma have to add bacteria of the right type. The ones in red!

But its not toxic as it is now.

Here is another article

Sincerely Lasse

I am adding Fritz’s Turbo today.

 

[dedragon]

i would start a thread to ask any reefers in your area if they have a little rock or bio media to spare. established media is the best if you dont want to pay for expensive live rock from overseas

 

[cutter2001]

i would start a thread to ask any reefers in your area if they have a little rock or bio media to spare. established media is the best if you dont want to pay for expensive live rock from overseas

I have added two media cylinders from my lfs’s coral frag tank. First was put in a week so. Second around four days ago. Nitrite still 9ppm per fish store test. My Hanna doesn’t go past .2ppm. Ammonia is still <1. Nitrate is in the high teens. Ph= 8.2. Just allowing it to cycle and adding Mycobacter-7 daily. I have stopped testing for Nitrite. Only Ammonia and nitrate.

 

[Randy Holmes-Farley Verified Community Expert]

Just to be clear, some of your nitrite tests say ppb and some say ppm. Are both correct where written?