Nitrite Level Way Too High

[JamesonFishi]

I'm having problems with my nitrite levels.

I have a 10 gallon tank with 2 tetra glofish (I had 3 but 1 died last week). I've had the tank going for about a month, and it came with a PF10 Tetra Whisper power filter. I was told to change my filter cartridge monthly, and this filter cartridge has been in there about two and a half weeks now, and I was also told to do a 30% water change every two weeks. I'm new to this, so I'm not sure if that's ideal or not. All the levels on my 5 in 1 test strips were where they should be the first few weeks, but the nitrites have started spiking. I noticed this first last week. On Thursday the NO2 was at 5ppm, and my smallest tetra died, so I did some 50% water changes and added some water balance until I got it back down to pretty close to zero. I've been checking the levels more frequently the past few days, and NO2 has stayed low, but today it's back up at 3ppm. Since Thursday's spike I've decreased the amount I've been feeding them (a pinch of food once a day, they usually eat all of it).

I already lost one fish, and I want to keep the other two as healthy as I can, but I don't know what's causing these spikes or how to make them stop. I've read that it can come from uneaten food, poop, or the filter. I haven't gotten a gravel vac yet, but I know that would help. Any advice on what the cause might be and how I can prevent it from happening again? Also, is there anything I can do to make this easier for the fish while I sort this out?

Thanks!

 

[Aiken Drum]

What do you know about the nitrogen cycle and cycling a tank?

Your tank isnt cycled and cant process out the waste your tank produces (ammonia) into less toxic nitrate.

Your test kit probably doesnt test for ammonia (most 5 in 1 test strips dont include ammonia on them) and its likely that you have a problem there too. Water changes are your friend.

I can give you some info on the nitrogen cycle and how to cycle a tank if its something you arent aware.

As to your filter, dont change filter cartridges unless they are literally falling apart. Changing filter cartridges can cause you to lose your cycle and you would start over every time you replace them. Just rinse them for as long as you can in water taken from your tank. Its really much better to throw the cartridges away, get some sponge and proper filter media in there that will last years with just a periodic rinse.

 

[JamesonFishi]

I have a very basic understanding of the nitrogen cycle, that bacteria breaks down waste into nitrogen-based material. It's been a long while since I got into the nitty gritty of it.

I don't know much about cycling my tank, though. Most of the information I got was from the pet store, and all they told me was to use Quick Start before adding fish and to change the water regularly. So I'd appreciate any info you can give me on tank cycling.

As for ammonia, I've been meaning to get a test kit for that, but I haven't had the chance yet.

 

[Aiken Drum]

Ill post some information on the nitrogen cycle and how to cycle the tank. Until you are able to test for ammonia i would change 30 to 50% of the water daily to ensure your ammonia isnt getting too high without you knowing.

 

[Aiken Drum]

The nitrogen cycle is the natural processes that go on in your tank that convert ammonia into less harmful substances.

Ammonia gets into your tank through various pathways. Fish waste, decaying uneaten food, and dead, decaying plants are common ammonia sources in an aquarium. Its also possible your tap water is an ammonia source. Chloramine is a common water treatment and when treated with most water conditioners the bond in the chloramine breaks and releases ammonia into the water.

Ammonia can be toxic to fish, depending on how much there is, and what the pH and temperature of your tank water is.

The first stage of the nitrogen cycle is the removal of ammonia. If you have real plants in your tank some of this ammonia will be absorbed as part of their natural growth. Generally though ammonia is consumed by denitrifying bacteria that lives mostly on your filter media. These bacteria consume the ammonia and produce nitrite. Unfortunately nitrite is pretty much as toxic to fish as ammonia.

The second stage of the nitrogen cycle is the removal of nitrite. A different denitrifying bacteria will consume the nitrite and produce nitrate. Nitrate is much less harmful than ammonia and nitrite, and for most aquariums the nitrogen cycle ends there. Excess nitrate is removed through your regular water changes.

A further stage of the nitrogen cycle can also happen, but its difficult to remove all the nitrate from a typical freshwater aquarium. Plants will absorb some nitrate in a similar manner to how it absorbs ammonia to grow. There are also nitrifying bacteria that consumes nitrate and gives off nitrogen gas which will simply offgas from your aquarium. This nitrifying bacteria is difficult to grow in freshwater aquarium.

“Cycling” a tank is the process you go through to grow denitrifying bacteria in your aquarium to consume ammonia and nitrite. You are said to be “cycled” when you have enough bacteria to consume all the ammonia and nitrite that your tank produces and turns all of it into nitrate. If you test the water of a cycled tank you should see 0 ammonia and nitrite and some nitrate.

 

[Aiken Drum]

To cycle a tank you need to grow denitrifying bacteria to consume ammonia and nitrite that your tank produces. The bacteria needs an ammonia source to grow colonies sufficient in size to consume all the ammonia and resultant nitrite and turn it into nitrate which typically you remove through your regular water changes.

A fish in cycle uses fish waste as an ammonia source and regular water changes are undertaken to ensure that water parameters are maintained at relatively non toxic levels.

Set up your tank. Make sure everything is running smoothly. Make sure you have used a water conditioner product with any tap water you have put in your tank. Seachem Prime is a water conditioner that will also detoxify some ammonia for a day or two, so is a good choice for a water conditioner while cycling a tank with fish.

You should have a test kit. Preferably a liquid test kit. It should test for ammonia, nitrite, and nitrate.

In ideal circumstances you should be starting a fishless cycle with a low bioload (number of fish). 1 small fish per 10 gallons/40 litres is a good number of fish, but this can be tweaked a little for fish that are social and don’t do well on their own. Ideally a hardy type of fish. You may have fully stocked (or overstocked) your tank before you knew about cycling. In these circumstances, if its not possible to return fish, you will have to make the best of it.

If you haven’t already done so, add your fish. Acclimate them to the water in your tank before doing so.

Feed lightly to start with. Daily as much as is eaten in 2 minutes, or as much as is eaten in 3 minutes every 2 days. You can increase to full feedings if you are confident your parameters aren’t getting too elevated too quickly and water changes don’t become a daily thing.

Start to regularly test the water for ammonia and nitrite. At least daily. Depending on your bioload you could start to see ammonia quite quickly. Nitrite will likely take a little longer to appear.

Your target should be to keep ammonia + nitrite combined no higher than 0.5ppm by changing water whenever your water parameters exceed this target. 0.5ppm combined is a level of waste that is sufficient for your cycle to establish but relatively safe for your fish.

If you see 0.5ppm ammonia and 0.0ppm nitrite (0.5ppm combined) then leave things be. If you see 0.5ppm ammonia and 0.25ppm nitrite (0.75ppm combined) then change 1/3 of the water. If you see 0.25ppm ammonia and 0.75ppm nitrite (1.0ppm combined) then change 1/2 the water. If water parameters get worse than these levels it may require multiple daily 50% water changes to maintain safe water conditions. This is more likely to happen with a fully stocked tank.

Remember to add water conditioner whenever you put tap water in the tank.

Over time the frequency of water changes and amount you need to change to maintain your ammonia + nitrite combined target will reduce. You can also start testing for nitrate and should see this rising. If you are finding the ammonia and nitrite in your tests are consistently low, and you aren’t already fully stocked, you can add a few more fish. It may take a few weeks to get to this point.

Once you add a few more fish, continue to regularly test the water and continue to change water if you exceed the 0.5ppm combined ammonia + nitrite target. With added bioload the frequency of water changes and amount you need to change may increase again until your cycle has caught up. Again once you are consistently seeing low ammonia and nitrite you can add some more fish. Rinse and repeat with testing, water changes, and adding fish when safe to do so until you are fully stocked.

You can then cut back on water changes to control nitrate only. Typically you want to keep nitrate no higher than 40ppm, but I would recommend changing some water every 2 weeks even if your water test says you don’t need to.

A fish in cycle from an empty tank to fully stocked can take several months.

A good way to speed up this process would be to put a small amount of filter media from an established filter into your filter, or get a sponge from an established filter and squeeze it into your tank water. Perhaps you have a friend who keeps fish who could let you have some? This will seed your filter with the bacteria you are trying to grow and speed up the process.

Another option is bottled bacteria like Dr Tims One + Only or Tetra Safestart. These products wont instantly cycle a tank as they claim but in a similar manner to adding established filter media they can seed your filter with the bacteria you are trying to grow to establish your cycle. These products are hit and miss as to whether they work at all, but are an option if established filter media isnt obtainable and may speed up the process from several months to several weeks.

 

[JamesonFishi]

This is super super helpful. Thanks!

 

[Joe_D]

I will just add to Anikin 's great info ..

Nitrate is not nearly as toxic to fish as Ammonia and Nitrites are unless it is at really high levels. How high is too high is debated by some.
In any event, if you have real plants they need some nitrate to grow
So, you need a balance in your tank, just as nature achieves.

 

[gilpi]

Lots of good detailed information here for you. I remember decades ago, someone having to pound on me that a filter always needs to be dirty and to never change it, just rinse it in tank water. This didn't make any sense to me as I didn't know about the cycling process. Your nitrites spiking is part of that process. So you are basically doing a "fish in cycle". I won't get into the cycling part of it as you have been given very good advice on how to proceed.