New Tank Cycle

[brian.saylor]

I have a 55gal tank with a filter rated for 110gal. The tank has been cycling since 11/29/17 with fish in. I saw the ammonia spike and now it is at 0 ppm, Nitrites are at 1.0 ppm and Nitrates are between 10 and 20 ppm. I just did a 50% water change on Monday, bringing the Nitrites down to 0.5 ppm and dropping the Nitrates to about 5 ppm. I was careful not to disturb the substrate when changing the water. Now, not even 48 hours later, the Nitrites are back to 1.0 ppm and the Nitrates are back to 10 ppm.

The temperature is about 79°F and the pH is 7.2. What am I doing wrong and why can't I get the Nitrites down?

 

[ZxC]

I have a 55gal tank with a filter rated for 110gal. The tank has been cycling since 11/29/17 with fish in. I saw the ammonia spike and now it is at 0 ppm, Nitrites are at 1.0 ppm and Nitrates are between 10 and 20 ppm. I just did a 50% water change on Monday, bringing the Nitrites down to 0.5 ppm and dropping the Nitrates to about 5 ppm. I was careful not to disturb the substrate when changing the water. Now, not even 48 hours later, the Nitrites are back to 1.0 ppm and the Nitrates are back to 10 ppm.

The temperature is about 79°F and the pH is 7.2. What am I doing wrong and why can't I get the Nitrites down?

Not enough bacteria in your system to convert the nitrite to nitrate, only thing you can do is wait for the population to increase, eventually leaving no nitrites.

 

[brian.saylor]

Not enough bacteria in your system to convert the nitrite to nitrate, only thing you can do is wait for the population to increase, eventually leaving no nitrites.

Will continuing with 15-20% water changes every few days help or hurt the cycle? I want to keep the levels in check as to not put too much stress on the fish. Should I be dosing the tank with anything to help speed up the process? (Nite Out, Stability, Prime, etc)

 

[ZxC]

Will continuing with 15-20% water changes every few days help or hurt the cycle? I want to keep the levels in check as to not put too much stress on the fish. Should I be dosing the tank with anything to help speed up the process? (Nite Out, Stability, Prime, etc)

You can try products made as bacterial cultures to speed up the population growth. Unfortunately your situation will be a slow tedious process, more nitrite will speed up population growth but hurt your livestock, less nitrite will slow population growth but be easier on your livestock... Its a rock and a hard place scenario. My vote will be for keeping nitrites low, and having it take a little longer to reduce the effects on fish short term. Prime may help, I'm not sure off the top of my head if it detoxifies nitrite though.

 

[brian.saylor]

You can try products made as bacterial cultures to speed up the population growth. Unfortunately your situation will be a slow tedious process, more nitrite will speed up population growth but hurt your livestock, less nitrite will slow population growth but be easier on your livestock... Its a rock and a hard place scenario. My vote will be for keeping nitrites low, and having it take a little longer to reduce the effects on fish short term. Prime may help, I'm not sure off the top of my head if it detoxifies nitrite though.

Thanks for the answers and insight. I will dose with Prime and continue to monitor nitrites. I figured the bacteria responsible for conversion weren't established, just thought they would grow a little quicker than they are.

 

[ZxC]

Some cycles take a few months lol, some take a week or two.

 

[jc102]

I was in a similar situation when I first started in the hobby. It took a little over 2 months before my tank finally stabilized! You just have to have patience. Definitely use Prime as it does detoxify ammonia, nitrite, and nitrate.

 

[brian.saylor]

I was in a similar situation when I first started in the hobby. It took a little over 2 months before my tank finally stabilized! You just have to have patience. Definitely use Prime as it does detoxify ammonia, nitrite, and nitrate.

Thank you for the info. I will definitely continue using the Prime.

 

[lewis.r]

Some cycles take a few months lol, some take a week or two.

Mine took around 2 months too! Although it was an accidental fish in cycle as I didn’t know any better at that point until I did a load of research.

I’m sure the daily water changes slowed the process down however

 

[brian.saylor]

Mine took around 2 months too! Although it was an accidental fish in cycle as I didn’t know any better at that point until I did a load of research.

I’m sure the daily water changes slowed the process down however

Thanks for the info.

 

[jc102]

It's worth the wait. The frequent water changes will help with ammonia spikes.

 

[brian.saylor]

I tested my water this morning, with the following results:

- pH - 6.2
- Ammonia - 0 ppm
- Nitrite - 0.25 ppm
- Nitrate - 5 ppm

The nitrites were 1.0 ppm and the pH was 7.2, the middle of the week. The pH has been pretty consistent at 7.2 - 7.4 throughout.

- Does this now mean I'm close to finishing the cycle?
- Will my pH return to where it was when the cycle is complete? Do I need to add something to bring it up?

 

[jc102]

pH will fluctuate during the cycling process. You should see your nitrItes dimish to 0ppm and nitrAtes increase. Once you get consistent readings with no ammonia, no nitrIte, and 10-20ppm nitrAte, you should feel confident that your tank is cycled. Once it is cycled, check the pH reading a few times and it should stabilize and stop fluctuating.

 

[brian.saylor]

pH will fluctuate during the cycling process. You should see your nitrItes dimish to 0ppm and nitrAtes increase. Once you get consistent readings with no ammonia, no nitrIte, and 10-20ppm nitrAte, you should feel confident that your tank is cycled. Once it is cycled, check the pH reading a few times and it should stabilize and stop fluctuating.

The pH really only dropped this week. It has been pretty consistent at about 7.2 since we started the tank the end of November. I've been doing water tests every few days, and treating with Prime while the nitrites were higher, as to not stress the fish too much. I'd like to add more inhabitants, but am patiently waiting until it's stable.

 

[WestCoast-Kelly]

Is it beyond time where some filter media from an established tank would help?

I cycled my brand new tank and filter over Xmas fishless, with Prime and media from a friend’s tank. It’s holding steady now with 6 Cory and 6 Tetra.

 

[King Fisher]

The pH really only dropped this week. It has been pretty consistent at about 7.2 since we started the tank the end of November. I've been doing water tests every few days, and treating with Prime while the nitrites were higher, as to not stress the fish too much. I'd like to add more inhabitants, but am patiently waiting until it's stable.

You could go to your fish shop and get liquid Tetra Beneficial Bacteria and add it to your tank. If you have consistently low pH your tank will take forever to cycle. I've found that by adding air stones and turning them up fairly high you are able to increase the pH a bit.