5 Gallon Tank Nitrites not going down in 5 gallon

So I am doing a fish in cycle on my 5 gallon tank. I know it’s not ideal, but I wasn’t well informed when I started this and the store refused the return of my fish so I have had no choice.

Parameters for the past two days are as follows

ammonia - 0
Nitrites - 0.1
Nitrates - 5
pH - 7

I have one glofish tetra inside. She’s been in since the beginning and is doing extremely well (I learned they are schooling fish so I am getting my 20 gallon this coming weekend and I will switch her into that and get her some friends!)

I am dosing with prime to detoxify and using bacteria in a bottle. Everything spiked over the course of the first few days and have now leveled out but I’m still seeing that 0.1 PPm of nitrites.

i do have duckweed and a pothos in the tank. The pothos doesn’t have roots yet as it’s a clipping. So I’m waiting for that but my duckweeds roots are about an inch long!

I have tested my water source and it’s pulling up 0 for everything!

My question is, how do I get the nitrites down to zero. Do I just wait it out and see? All other levels are fine after my 50% water change 2 days ago cuz my nitrates were above 40, so I don’t think a water change is the answer. Any help or suggestions are welcome!

 

Hi Shania
Welcome to the forum.

Many of us found ourselves doing a fish in cycle because of lack of knowledge. It’s no big deal you have come to the right place.

Have you tested your tap water for nitrates and nitrites? That will tell you your true zero.

The answer is change some water often.

By all means test the old water if you have time but if you don’t have time for both then just change some water.

In my opinion you are at an advantage because you will learn early on in the hobby that a water change is a three minute job . You have the opportunity to learn how to smash out a quick water change before breakfast or after midnight. Don’t concern yourself with people that write of stressing out fish by doing a water change. Trust me if a fish has the option between being in toxic waste or fresh water it would say “ give me clean water “ if only they could speak.

Limit the chances to a maximum of 50% at one time and try to match the temperature. Have a routine with the de chlorinator perhaps tossing the measuring spoon into the bucket each time so you know 100% when that job has been done.
Buy a couple of new buckets and always have de chlorinator on hand.

I will finish this long reply by saying don’t rely on adding more Prime to detox ammonia. Just change some water.

 

Hi Shania
Welcome to the forum.

Many of us found ourselves doing a fish in cycle because of lack of knowledge. It’s no big deal you have come to the right place.

Have you tested your tap water for nitrates and nitrites? That will tell you your true zero.

The answer is change some water often.

By all means test the old water if you have time but if you don’t have time for both then just change some water.

In my opinion you are at an advantage because you will learn early on in the hobby that a water change is a three minute job . You have the opportunity to learn how to smash out a quick water change before breakfast or after midnight. Don’t concern yourself with people that write of stressing out fish by doing a water change. Trust me if a fish has the option between being in toxic waste or fresh water it would say “ give me clean water “ if only they could speak.

Limit the chances to a maximum of 50% at one time and try to match the temperature. Have a routine with the de chlorinator perhaps tossing the measuring spoon into the bucket each time so you know 100% when that job has been done.
Buy a couple of new buckets and always have de chlorinator on hand.

I will finish this long reply by saying don’t rely on adding more Prime to detox ammonia. Just change some water.

Thank you for your reply! I have come here to learn a lot about fish keeping so I figured why not join!

I have tested my source water and everything comes up at 0 so I know I’m not adding anything bad into my tank!

my water changes are very fast… 5 minutes at the most. And I’m doing anywhere from 25-50% based off the levels I’m getting.

But now my nitrates are in target range and I’m worried about doing another water change to remove the 0.1 of nitrites because then I will remove too many nitrates? No? can my nitrates go down to less and still keep the cycle going?

The only reason I’m dosing with prime right now is to keep the water as safe as possible for the fish while not slowing down or stalling my cycle. Once my parameters are indicating that it’s cycled I’ll only be using prime as a conditioner, not to detoxify the ammonia or nitrites. I’ll be clearing the ammonia out through water changes. I’m just worried that too many water changes right now will stall my cycle !

ahhhhhhh I feel like I maybe should have taken chemistry in highschool

thank again for your help ❤️

 

Just be patient and change enough water if ammonia or nitrite get above .5ppm. Prime only works as a water conditioner and doesn't detoxify anything other than chlorine. without getting into it, your water detoxifies ammonia and nitrite naturally

Thank you for your reply! I have come here to learn a lot about fish keeping so I figured why not join!

I have tested my source water and everything comes up at 0 so I know I’m not adding anything bad into my tank!

my water changes are very fast… 5 minutes at the most. And I’m doing anywhere from 25-50% based off the levels I’m getting.

But now my nitrates are in target range and I’m worried about doing another water change to remove the 0.1 of nitrites because then I will remove too many nitrates? No? can my nitrates go down to less and still keep the cycle going?

The only reason I’m dosing with prime right now is to keep the water as safe as possible for the fish while not slowing down or stalling my cycle. Once my parameters are indicating that it’s cycled I’ll only be using prime as a conditioner, not to detoxify the ammonia or nitrites. I’ll be clearing the ammonia out through water changes. I’m just worried that too many water changes right now will stall my cycle !

ahhhhhhh I feel like I maybe should have taken chemistry in highschool

thank again for your help ❤️

you also don't need to have nitrates in a certain range. they should stay under 20ppm (ideally 0), they're just a byproduct of ammonia and nitrite.

 

Just be patient and change enough water if ammonia or nitrite get above .5ppm. Prime only works as a water conditioner and doesn't detoxify anything other than chlorine. without getting into it, your water detoxifies ammonia and nitrite naturally

you also don't need to have nitrates in a certain range. they should stay under 20ppm (ideally 0), they're just a byproduct of ammonia and nitrite.

I’m a little confused as to how prime doesn’t detoxify ammonia and nitrite… it doesn’t remove it… but it does detoxify through a binding process. Does it not? If not then how is it that they are marketing it as such and how are so many people using it for that exact purpose with fish-in cycling?

and while I understand the nitrates are the byproduct, they are also what eat your nitrites… if I remove too much won’t my nitrites spike ?

genuinely asking as this is what I have come to understand about the cycling process. Without nitrates you cannot control nitrites.

so if I remove too many nitrates from a tank that hasn’t completed cycling, won’t I just be back to square one?

 

I will not waste time trying to convince anyone that prime doesn’t detox anything. They themselves can explain that they don’t have any scientific proof and their claims are based on what their customers told them. In a word marketing.
Prime is an extremely good de chlorinator.


Nitrates are bacteria poop , not the bacteria themselves .

Nitrite is bacteria poop from a different strain of bacteria.


Bacteria live ON hard surfaces. We need to be careful in a new tank not to clean any hard surfaces. Yes the filter has bacteria ON it but bacteria decide where they want to live. Mostly in the current of food. That can be on the glass directly in line with the flow from the filter. But all ornaments, rocks plants , plastic oranges castles etc are all potential homes for bacteria. At least for the first few months be careful cleaning the glass. Do not deep vacuum a new tank. At least for the next few weeks/ months don’t deep clean the gravel. Hold the vacuum just above the substrate that will pick up solids.

In a few months yes push the vacuum deep into the substrate and pull out as much poop as you want. In theory we should only clean 1/3 or 1/2 of the gravel in an established tank . But in reality in 12 months you could clean all the gravel one week then all the glass the next. We are always careful rinsing filters.

WE NEVER REPLACE filter cartridges/ sponges/ fabric/ pads etc. only after a couple of years do we replace worn out fabric etc . And even then we replace some leaving some old beside the new.

Nitrates are bacteria poop not the bacteria themselves.

Edit to add.
The manufacturers would like us to buy new cartridges every month. Give your money to a charity of your choice.

 

I will not waste time trying to convince anyone that prime doesn’t detox anything. They themselves can explain that they don’t have any scientific proof and their claims are based on what their customers told them. In a word marketing.
Prime is an extremely good de chlorinator.


Nitrates are bacteria poop , not the bacteria themselves .

Nitrite is bacteria poop from a different strain of bacteria.


Bacteria live ON hard surfaces. We need to be careful in a new tank not to clean any hard surfaces. Yes the filter has bacteria ON it but bacteria decide where they want to live. Mostly in the current of food. That can be on the glass directly in line with the flow from the filter. But all ornaments, rocks plants , plastic oranges castles etc are all potential homes for bacteria. At least for the first few months be careful cleaning the glass. Do not deep vacuum a new tank. At least for the next few weeks/ months don’t deep clean the gravel. Hold the vacuum just above the substrate that will pick up solids.

In a few months yes push the vacuum deep into the substrate and pull out as much poop as you want. In theory we should only clean 1/3 or 1/2 of the gravel in an established tank . But in reality in 12 months you could clean all the gravel one week then all the glass the next. We are always careful rinsing filters.

WE NEVER REPLACE filter cartridges/ sponges/ fabric/ pads etc. only after a couple of years do we replace worn out fabric etc . And even then we replace some leaving some old beside the new.

Nitrates are bacteria poop not the bacteria themselves.

This makes total sense! I was under the assumption that ammonia, nitrites, and nitrates were bacteria all together. Now I’m understanding! Thanks for dumbing it down for me!

as for prime I totally get that there’s no real proof! But my fish is happy and thriving so I’m gonna just keep doing what I’m doing until my tank is fully cycled. May be a sense of false hope but false hope is better than no hope but definitely good to know that it hasn’t been proven to detox anything.

I havent cleaned anything in the tank. All I’ve done is water changes. I’ve only had the tank for a week so I haven’t vaccumed anything or done a deep clean as it’s hust

so based off what your saying, I should be totally fine to do a let’s say 25% water change and possible get those nitrites out of there and it won’t harm my cycle, as my beneficial bacteria is not living in the water. Correct?

If that’s the case then I do believe my tank to be fully cycled and just needs a small water change.

Thank you this was helpful <3

 

I did not read how long the tank has been running?

A fully functioning tank with colonies of both kinds of bacteria has zero ammonia and zero nitrites. As your tank has some nitrites in the test it’s not fully cycled.

Actually a better way to think about a cycle is to think of it as a constantly changing number of bacteria. A established tank has enough bacteria for only the number of fish in it . It’s daily bio load / poop load. Even a 10 year old tank needs to grow more bacteria when more fish are added. So think of a cycle as a constantly changing number of bacteria rather than a switch. It’s not ever fully cycled.

It is said in an established tank bacteria can double their numbers in 24 hours so a pair of fish that has a batch of fry hatch they are not really in any danger from the new bio load. But you can’t add two dozen new adult fish to a ten year old tank that has only had a pair of fish in it without expecting a “mini cycle.”

 

I’m a little confused as to how prime doesn’t detoxify ammonia and nitrite… it doesn’t remove it… but it does detoxify through a binding process. Does it not? If not then how is it that they are marketing it as such and how are so many people using it for that exact purpose with fish-in cycling?

and while I understand the nitrates are the byproduct, they are also what eat your nitrites… if I remove too much won’t my nitrites spike ?

genuinely asking as this is what I have come to understand about the cycling process. Without nitrates you cannot control nitrites.

so if I remove too many nitrates from a tank that hasn’t completed cycling, won’t I just be back to square one?

because ammonia comes in two forms: toxic and nontoxic. if your pH is under 8 then almost 99% of the ammonia is nontoxic. also, nitrates don’t eat nitrites. bacteria eats nitrites and then produces nitrates. nitrates are basically a waste product. plants don’t take nitrates up unless they are at peak photosynthesis, they prefer ammonia and nitrite over nitrate, so it’s best to keep nitrates under 20ppm because nitrate is still a toxic product and is hardly ever seen over 5ppm in natural systems unless human intervention is involved. hope that cleared it up for you.

because ammonia comes in two forms toxic and nontoxic. if your pH is under 8 then almost 99% of the ammonia is nontoxic. also, nitrates don’t eat nitrites. bacteria eats nitrites and then produces nitrates. nitrates are basically a waste product. plants don’t take nitrates up unless they are at peak photosynthesis, they prefer ammonia and nitrite over nitrate. so it’s best to keep nitrates under 20ppm because nitrate is still a toxic product and is hardly ever seen over 5ppm in natural systems unless human intervention is involved. hope that cleared it up for you.

edit: nitrite is more toxic at lower pH than higher pH and can easily be mitigated by adding salt to the water. it just takes a little understanding of science and chemistry to understand that prime doesn’t do anything to detoxify anything other than chlorine but that’s a conversation for people who are actually interested lol

 

because ammonia comes in two forms: toxic and nontoxic. if your pH is under 8 then almost 99% of the ammonia is nontoxic. also, nitrates don’t eat nitrites. bacteria eats nitrites and then produces nitrates. nitrates are basically a waste product. plants don’t take nitrates up unless they are at peak photosynthesis, they prefer ammonia and nitrite over nitrate, so it’s best to keep nitrates under 20ppm because nitrate is still a toxic product and is hardly ever seen over 5ppm in natural systems unless human intervention is involved. hope that cleared it up for you.

edit: nitrite is more toxic at lower pH than higher pH and can easily be mitigated by adding salt to the water. it just takes a little understanding of science and chemistry to understand that prime doesn’t do anything to detoxify anything other than chlorine but that’s a conversation for people who are actually interested lol

This makes sense! I appreciate you taking the time to respond and explain.

my parameters are still the exact same today. Nothing at all has changed

ammonia - 0
Nitrites - 0.1
Nitrates - 5
pH - 7

im now wondering since I am only using API to test the ammonia (my other tests are all by fluval) they didn’t have the master kit available at my LFS so I had to buy individual. But it is my understanding that the fluval test for nitrites is more sensitive (detecting as low as 0.1ppm when’re the api kit only starts at 0.25ppm). So if I was using the APi test kit it would read as 0ppm Nitrites. So I would have assumed my tank has been cycled for 3 days now! How do people know if their tank is fully cycled when API nitrite tests isn’t picking up as low as 0.1ppm?

Is my test just faulty? Should I switch to the API?

they still don’t have it at my LFS but I can probably just order from Amazon

 

To test if a tank is cycled.
Continue testing the water without doing a water change. When you can go a full week without seeing ammonia or nitrites it’s a good sign the tank has a fully functioning cycle. At least for the volume of the fish currently in the tank.

I did not want to confuse the issue of the toxicity of ammonia because you are new. Because it’s temperature and PH related and we may have no control over temperature in summer or the PH can change overnight i believe it’s safer to say any ammonia is toxic.
But since you are now learning of the possibility that ammonia can be harmless ammonium and our tests cannot tell the difference here is a chart for your reference.

 

To test if a tank is cycled.
Continue testing the water without doing a water change. When you can go a full week without seeing ammonia or nitrites it’s a good sign the tank has a fully functioning cycle. At least for the volume of the fish currently in the tank.

I did not want to confuse the issue of the toxicity of ammonia because you are new. Because it’s temperature and PH related and we may have no control over temperature in summer or the PH can change overnight i believe it’s safer to say any ammonia is toxic.
But since you are now learning of the possibility that ammonia can be harmless ammonium and our tests cannot tell the difference here is a chart for your reference.

Oh wow I appreciate this chart! That’s very interesting! So essentially since my water is 25° and my pH is at 7 I would absolutely need to water chabge once ammonia hits 4 (if I’m readingthat chart correctly) . But that’s only if the temp and ph are steady like that. If they fluctuate then I have to change that value and do a WC either sooner or later. That’s essentially what this means correct? if that’s the case this is very interesting! I guess this just reiterated the importance of testing for everything and not just some things!

Also while I have you here, you mentioned the population of my tank. It currently stands at 1 and I don’t plan on adding anymore to my 5 gallon. But I am getting a 20 on Friday. And since my glofish is meant to be a schooling fish I am planning on getting her some friends. I guess when I add them I should expect a bit of a cycle to happen so that more bacteria can grow to support the new fish? How many can I safely add without completely crashing the cycle? I was thinking no more than 3 ?

 

When we have a small number of fish and add lots more the word we use is “ mini cycle “
We say the tank is having a mini cycle.

Having a tank do a mini cycle is no big deal. A few extra water changes in the first two weeks is all I consider necessary. Personally I feel the time and effort needed to test water for all the tests is better spent smashing out a water change. But that’s just me. Having burnt my way through 3 master test kits at $90 Australian I now don’t test as often as I perhaps should?

It is said that in a warm tropical fish tank bacteria can double in numbers in 24 hours.
So the first week is the important time to test or change water.

Always remember humans have been keeping fish for over 2000 years ( goldfish in China) .
We in the western world with glass boxes only one hundred years.
The nitrogen cycle was only understood 40 years ago.

The safe number of new fish you can add is directly related to how often you are prepared to replace toxic water.

 

This makes sense! I appreciate you taking the time to respond and explain.

my parameters are still the exact same today. Nothing at all has changed

ammonia - 0
Nitrites - 0.1
Nitrates - 5
pH - 7

im now wondering since I am only using API to test the ammonia (my other tests are all by fluval) they didn’t have the master kit available at my LFS so I had to buy individual. But it is my understanding that the fluval test for nitrites is more sensitive (detecting as low as 0.1ppm when’re the api kit only starts at 0.25ppm). So if I was using the APi test kit it would read as 0ppm Nitrites. So I would have assumed my tank has been cycled for 3 days now! How do people know if their tank is fully cycled when API nitrite tests isn’t picking up as low as 0.1ppm?

Is my test just faulty? Should I switch to the API?

they still don’t have it at my LFS but I can probably just order from Amazon

you are probably getting a false positive from the fluval test. best way to check is to test your tap water or a source of water with 0 nitrite.

here’s a link to calculate the ammonia in your tank as well Free Ammonia Calculator

Oh wow I appreciate this chart! That’s very interesting! So essentially since my water is 25° and my pH is at 7 I would absolutely need to water chabge once ammonia hits 4 (if I’m readingthat chart correctly) . But that’s only if the temp and ph are steady like that. If they fluctuate then I have to change that value and do a WC either sooner or later. That’s essentially what this means correct? if that’s the case this is very interesting! I guess this just reiterated the importance of testing for everything and not just some things!

Also while I have you here, you mentioned the population of my tank. It currently stands at 1 and I don’t plan on adding anymore to my 5 gallon. But I am getting a 20 on Friday. And since my glofish is meant to be a schooling fish I am planning on getting her some friends. I guess when I add them I should expect a bit of a cycle to happen so that more bacteria can grow to support the new fish? How many can I safely add without completely crashing the cycle? I was thinking no more than 3 ?

Glofish (schooling fish) need to be in groups of at least 5-6 of their own kind. If you were to do another fish in cycle for the 20 gallon then I would just get 5 more fish (make sure they’re the same kind of glofish!) and do water changes as needed. you can also transfer the filter of the 5 gallon to the 20 gallon to help “kickstart” the cycle as well. i would not add anymore fish to the 5 gallon though.

 

When we have a small number of fish and add lots more the word we use is “ mini cycle “
We say the tank is having a mini cycle.

Having a tank do a mini cycle is no big deal. A few extra water changes in the first two weeks is all I consider necessary. Personally I feel the time and effort needed to test water for all the tests is better spent smashing out a water change. But that’s just me. Having burnt my way through 3 master test kits at $90 Australian I now don’t test as often as I perhaps should?

It is said that in a warm tropical fish tank bacteria can double in numbers in 24 hours.
So the first week is the important time to test or change water.

Always remember humans have been keeping fish for over 2000 years ( goldfish in China) .
We in the western world with glass boxes only one hundred years.
The nitrogen cycle was only understood 40 years ago.

The safe number of new fish you can add is directly related to how often you are prepared to replace toxic water.

you are probably getting a false positive from the fluval test. best way to check is to test your tap water or a source of water with 0 nitrite.

here’s a link to calculate the ammonia in your tank as well Free Ammonia Calculator

Glofish (schooling fish) need to be in groups of at least 5-6 of their own kind. If you were to do another fish in cycle for the 20 gallon then I would just get 5 more fish (make sure they’re the same kind of glofish!) and do water changes as needed. you can also transfer the filter of the 5 gallon to the 20 gallon to help “kickstart” the cycle as well. i would not add anymore fish to the 5 gallon though.

Yes I’m planning on sticking with the neon tetras in the 20 gallon. I’ll be keeping my 5 gallon as a hospita tank!

The 20 gallon im getting is coming from my mom. It’s coming with all the seeded media and everything so I shouldn’t have to worry about cycling the 20 gal. She used it as a breeder tank and it has 60 baby mollies inside so I think it should be seeded enough to handle the 5-6 glofish tetras im gonna put in! And I’ll be sure to watch my parameters closely for the first few weeks! She will be taking her babies out Friday morning and bringing me the tank Friday afternoon so I shouldn’t lose too much of the BB

 

This makes total sense! I was under the assumption that ammonia, nitrites, and nitrates were bacteria all together. Now I’m understanding! Thanks for dumbing it down for me!

Even though we call it a cycle, it is really a food chain. Ammonia is eaten by bacteria that excrete nitrite as waste. Different bacteria consume the nitrites and excrete nitrate. Plants can consume some nitrates, but in general we remove the nitrates with water changes. If the tank has 40 ppm of nitrates, and you change 25% of the water (adding water with 0 ppm nitrates), the result should be 30 ppm in the remaining water in your tank. A 50% water change would leave 20 ppm and so on. Good luck

 

Now I’m getting discouraged….
Past 3 days of readings were

ammonia - 0
Nitrites - 0.1
Nitrates - 5

now this morning I’m back up to

ammonia - 0
Nitrites - 0.8
Nitrates - 10

just when I think I’m right there it takes another step back!

 

Patience is a virtue! It is getting there, but a fish in cycle actually takes longer because of the water changes, and a fishless cycle can take up to 2 months sometimes. Stay the course and do water changes.