20 Gallon Tank Nitrites not going down? helpppp

je0409

I'm currently cycling my first ever tank, so I am very new to this and didn't even know about the nitrogen cycle before I started this. I'm doing a fishless cycle and my tank has been cycling for a few weeks now. My problem is that I have high levels of nitrates (about 120ppm) but also very high levels of nitrites (my test goes up to 10ppm but the color seems much deeper than anything on the test so I assume it's even higher). The nitrates are steady at 120ppm but the nitrites aren't decreasing at all, and it's been this way for almost a week. I did about a 15% water change a few days ago but that didn't do anything. I know my test isn't faulty because I've tried different ones and got the same readings each time. I really wanna add fish as soon as possible but I just don't understand why my nitrites aren't going down!! Also I've been adding a half dose of ammonia every other day bc I'm afraid of the bacteria starving and accidentally breaking the cycle. Any help would be greatly appreciated!!
 

Dunk2

I'd guess you're adding too much ammonia too quickly. What is your ammonia level and pH?

High nitrite can inhibit beneficial bacteria growth and stall your cycle. I'd suggest you do a large water change to get the nitrite and nitrate levels down.

What ammonia source are you using and what is your water temperature?
 
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Ouse

15% water changes aren’t enough to bring the nitrite down. Do a 50% water change and see what that does. If it doesn’t lower it enough then do another a bit later.

I recommend adding your source of ammonia less frequently. If you’re using flake as the source then ensure it’s finely crushed and only in small portions. You might want to vacuum any excess. If you’re adding drops of ammonia you can dose as instructed by the bottle but just every two or three days from now on to ensure that you aren’t overwhelming the bacteria.

120ppm for nitrate is too high for fish and will kill them, so doing a large water change will reduce this. Aim for around 20ppm or lower as this is a safe and manageable level. Once you bring the nitrite to 0ppm and the nitrate to around 20ppm the cycle will be done.

Is there nitrite in your tap water?
 
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je0409

I'd guess you're adding too much ammonia too quickly. What is your ammonia level and pH?

High nitrite can inhibit beneficial bacteria growth and stall your cycle. I'd suggest you do a large water change to get the nitrite and nitrate levels down.

What ammonia source are you using and what is your water temperature?
My ammonia level was at 0 this morning with high levels of nitrite and nitrate so I added a half dose of Fritz Fishless Fuel. A full dose is supposed to get your tank to 2ppm. pH is between 7 and 7.5. Water temp is about 78F.
 
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Dunk2

My ammonia level was at 0 this morning with high levels of nitrite and nitrate so I added a half dose of Fritz Fishless Fuel. A full dose is supposed to get your tank to 2ppm. pH is between 7 and 7.5. Water temp is about 78F.

I’d do a large water change, bump the water temperature up to 82 to help the cycling process and re-dose ammonia to 2 ppm.

Don’t re-dose ammonia until it reaches 0.
 
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je0409

I’d do a large water change, bump the water temperature up to 82 to help the cycling process and re-dose ammonia to 2 ppm.

Don’t re-dose ammonia until it reaches 0.
Will do!! Thank you both so much!
 
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mattgirl

High nitrites and nitrates alone are not going to stall the cycle but having them this high will take much longer for them to go down. Getting both down with water changes will help finish up the cycle sooner. Be sure you temp match and add your water conditioner to the fresh water before pouring it in the tank. We can't see the bacteria but it is a living thing thus the reason for temp matching the water even though there are no fish in this tank.
 
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je0409

Okay I need more help! I did a 50% water change yesterday and redosed ammonia and got it to 2ppm. I tested the water just now and my nitrites and nitrates are still very high. Pretty much no change, except that my pH is a little low now because I have soft tap water (I added a little baking soda to get it back to 7). I don't see how it's possible that there was no change when I took out so much water. I'm pretty sure my tap water doesn't have nitrites because when I was first cycling the tank there was no presence of nitrites for a long time in the tank. I feel like I should add that about a week ago I added some Fluval Biomax ceramic rings to my filter so IDK maybe the nitrites didn't go down bc they're clinging to that? I don't know how it works honestly. Please help me I feel like I'm going crazy lol
 
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Dunk2

What exactly were your parameters before and after the water change?

If you need to buffer and stabilize your pH, I’d suggest using crushed coral and not baking soda.

The biomax rings are where your beneficial bacteria will grow to consume ammonia and nitrites. So they are a good thing!
 
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mattgirl

It is very possible that both nitrites and nitrates are so high even 50% water change didn't lower them a measurable amount. As long as your ammonia is still going down within 24 hours your cycle is still moving forward so there is no need to be overly concerned with what you are seeing.

Adding the media wouldn't have hurt the cycling process. Nitrite eating bacteria will grow on them. Once enough of it has grown the nitrites will drop down to zero. You really are still early in the cycling process if your aquarium detail are up to date. It says you started this cycle 2/20/21 If that is the case this tank has been running for less than a month. You really are about where you need to be at this point in the cycle.

I agree with Dunk2 Instead of adding baking soda I will recommend you put some crushed coral in your filter. It too have soft water and the crushed coral holds my pH up to a constant 7.2. Just put a handful of it in a media bag and put that bag in your filter. If all you can get is coral sand used about 1/2 cup of it. If you can get coral chunks add about a cup.
I don't know how it works honestly.
When we say we are cycling a tank it simply means we are growing ammonia and nitrite eating bacteria. Once we have enough of each of them we will start getting a zero reading in our test tubes.

Right now you have both ammonia and nitrite eating bacteria but just not enough of it yet. It takes time to grow enough to handle the full bio-load of a tank. In this case the ammonia you are adding is the bio-load. Once you add your fish their waste will be the bio-load.

As long as we add ammonia or we have fish in the tank producing ammonia there will still be ammonia thus nitrites in our tank. In a fully cycled tank we will have grown enough bacteria to almost instantly process the ammonia the fish are producing straight through to nitrites and almost instantly to nitrates.

Fish produce ammonia so we need to grow bacteria that will use that ammonia for food. Just like most everything in our world even bacteria poops. What ammonia eating bacteria poops out is nitrites. Nitrites are food for the second bacteria. It is our nitrite eating bacteria. What it poops out is Nitrates. Most of us never grow the third type of bacteria that will eat the nitrates so we keep them lowered by doing water changes.

To sum it up: Add crushed coral to hold at a constant pH level. If your ammonia goes back to zero within 24 hours add it again but never more often than every 24 hours. If the ammonia stops going down within 24 hours do another 50% water change to get the cycle moving forward again. The water changes are not going to harm the cycling process as long as you temp match and use your water conditioner.
 
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je0409

What exactly were your parameters before and after the water change?

If you need to buffer and stabilize your pH, I’d suggest using crushed coral and not baking soda.

The biomax rings are where your beneficial bacteria will grow to consume ammonia and nitrites. So they are a good thing!
BEFORE:
temp- 78F
pH- 7.5
ammonia- 0.5ppm
nitrite- above 10ppm
nitrate- 160ppm
KH- 240ppm
GH- 60ppm
AFTER:
temp- 80F
pH- 6.0 (back to 7 now)
ammonia- 2ppm (I redosed the fishless fuel)
nitrite- above 10ppm
nitrate- between 80 and 160 ppm
KH- 80ppm
GH- 30ppm
 
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mattgirl

I don't know how it works honestly.
In case you missed it because it was merged into my previous post I tried to answer this question for you. I hope it helps you understand what is happening.
 
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Dunk2

BEFORE:
temp- 78F
pH- 7.5
ammonia- 0.5ppm
nitrite- above 10ppm
nitrate- 160ppm
KH- 240ppm
GH- 60ppm
AFTER:
temp- 80F
pH- 6.0 (back to 7 now)
ammonia- 2ppm (I redosed the fishless fuel)
nitrite- above 10ppm
nitrate- between 80 and 160 ppm
KH- 80ppm
GH- 30ppm

Based on these parameters, I agree with mattgirl. Nitrites and nitrates were so high and likely “off the chart” that your water change appears to have done little to bring them down.

As I said in my original post, this is often what happens when you add too much ammonia too quick.
 
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Ouse

After doing a water change I’d wait before dosing on more ammonia.
 
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mattgirl

After doing a water change I’d wait before dosing on more ammonia.
Can you explain why you would wait before adding ammonia? How long do you think one should wait? We are all here to learn so I am trying to understand the reasoning behind this.
 
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Ouse

Can you explain why you would wait before adding ammonia? How long do you think one should wait? We are all here to learn so I am trying to understand the reasoning behind this.
They did a water change to lower nitrite and nitrate and by adding more ammonia after it’s going to cause both to spike faster. They also mentioned it being so high that even a 50% water change wasn’t enough to lower it by much.

I’d wait for a longer interval than usual to pass before adding more ammonia to the tank, maybe ranging from a day or possibly even three days. Depending on how much is added per dose the bacteria shouldn’t starve. I’ve cycled a tank with small flake portions every three days with success, producing little nitrate.
 
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mattgirl

They did a water change to lower nitrite and nitrate and by adding more ammonia after it’s going to cause both to spike faster. They also mentioned it being so high that even a 50% water change wasn’t enough to lower it by much.

I’d wait for a longer interval than usual to pass before adding more ammonia to the tank, maybe ranging from a day or possibly even three days. Depending on how much is added per dose the bacteria shouldn’t starve. I’ve cycled a tank with small flake portions every three days with success, producing little nitrate.
Thank you. I understand your reasoning now. You are right, adding ammonia daily at this point isn't totally necessary. Every other day or even every third day shouldn't be a problem but adding it daily shouldn't be either.

As long as the ammonia is being processed to zero within 24 hours of adding it the cycle is still moving forward. When we have fish in the tank they will be constantly adding ammonia. When fishless cycling we are trying to replicate what will happen once fish are added.

We will just be growing more ammonia and nitrite eating bacteria if we add it daily. Eventually there will be enough of both to zero out both ammonia and nitrite. The high nitrates can be removed with water changes once the cycle is complete.
 
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je0409

Okay so I think I need more help! I've done like three water changes since talking on here and everytime I change out more than 50%, check the ammonia, ammonia is at 0 so I add just a half dose, then the next day nitrates and nitrites are both super high again!! Should I do another water change? Should I stop adding ammonia? It seems to be going to 0 after every 24 hrs. I should add that I have a planted tank (I don't know if that changes anything) and I also now have quite a bit of brown algae stuck to my plants and hides that I also don't know how to get rid of.
 
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Ouse

The nitrite is spiking because the bacteria is growing and converting ammonia into nitrite. By all means don’t stop dosing on ammonia and since it’s fishless I think you should let it spike; nitrifying bacteria will grow but won’t bring nitrite down if it’s too high. You might want to change the water eventually but not now.
 
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mattgirl

As long as the ammonia you are adding is going down to 0 within 24 hours your cycle is still moving forward. Since it is going down we know the high nitrites and high nitrates are not affecting the cycle. Should the pH drop too low it might slow down the process so keep an eye on it and make sure it doesn't go any lower than about 7.

I have to ask, you said this is a planted tank. Are you adding any kind of fertilizer for the plants? Is it possible your high nitrites and/or nitrates are coming from something you are adding?
 
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je0409

As long as the ammonia you are adding is going down to 0 within 24 hours your cycle is still moving forward. Since it is going down we know the high nitrites and high nitrates are not affecting the cycle. Should the pH drop too low it might slow down the process so keep an eye on it and make sure it doesn't go any lower than about 7.

I have to ask, you said this is a planted tank. Are you adding any kind of fertilizer for the plants? Is it possible your high nitrites and/or nitrates are coming from something you are adding?
I add the instructed dose of Seachem Flourish once a week. I also have Seachem root tabs in my substrate
 
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mattgirl

I add the instructed dose of Seachem Flourish once a week. I also have Seachem root tabs in my substrate
I suspect some of the nitrates you are seeing are from the root tabs. I would hold off on adding the liquid ferts until you get a handle on these numbers. I have to think the plants will be getting all they need without adding any more. Stop adding it and maybe your plants will start eating some of the nitrates. The fewer things we add while cycling a tank the better it is.
 
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je0409

I suspect some of the nitrates you are seeing are from the root tabs. I would hold off on adding the liquid ferts until you get a handle on these numbers. I have to think the plants will be getting all they need without adding any more. Stop adding it and maybe your plants will start eating some of the nitrates. The fewer things we add while cycling a tank the better it is.
okay!! thank you everyone once again for the advice!! if it wasn't for this forum I would have smashed this tank by now lol
 
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Ouse

We’ve all felt that way in the hobby at least once.
 
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mattgirl

I could read back through the thread but I will ask instead. I see in your aquarium details you are using strips for testing. Have you had anyone else test your water with liquid tests or have you upgraded your testing supplies since filling out the details and are now using the liquid tests? Is it possible your test strips aren't telling you the whole truth?
 
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Ouse

Test strips are unreliable and I learned that the hard way. By trusting test strips I was forced to do a fish-in cycle before I knew how to do it. Mattgirl and I recommend a liquid test kit. I particularly like API Master.
 
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je0409

I could read back through the thread but I will ask instead. I see in your aquarium details you are using strips for testing. Have you had anyone else test your water with liquid tests or have you upgraded your testing supplies since filling out the details and are now using the liquid tests? Is it possible your test strips aren't telling you the whole truth?
I am still using the test strips but after reading this I will definitely go tomorrow to buy the API test master! I've seen a lot of other people also recommend it. Thanks for letting me know guys!! Hopefully I haven't been getting comepletely wrong readings.
 
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