Nitrite will not go away...

[Pomatomus]

Chances are you are seeing a spike because you are building up your BB again. A KH that low will cause the bacteria to die. They perform best when the KH is above 50ppm. You basically had old tank syndrome and now you are back to new tank syndrome. Ammonia-processing bacteria colonize faster than NO2 bacteria, so that may be why you still have nitrite.

Raise your alkalinity a little more and watch for improvement. Add a small amount of salt (fraction of a teaspoon per gallon) to reduce nitrite toxicity to trivial levels. I can calculate exactly how much salt you need if you want, but 1/4 tsp per gallon will be more than enough without killing your bb. Aeration will help too, as NO2 makes its harder for fish to transport oxygen to tissues. The chloride ion has greater binding affinity at the gill than NO2, so it will be taken up instead.

Also, do you have enough media or substrate to house a large bacterial population?

 

[pops]

good advice pom. just like to temper it with do not mess with PH or KH if you are not absolutely sure what you are doing.

 

[newyorkmfk]

Chances are you are seeing a spike because you are building up your BB again. A KH that low will cause the bacteria to die. They perform best when the KH is above 50ppm. You basically had old tank syndrome and now you are back to new tank syndrome. Ammonia-processing bacteria colonize faster than NO2 bacteria, so that may be why you still have nitrite.

Raise your alkalinity a little more and watch for improvement. Add a small amount of salt (fraction of a teaspoon per gallon) to reduce nitrite toxicity to trivial levels. I can calculate exactly how much salt you need if you want, but 1/4 tsp per gallon will be more than enough without killing your bb. Aeration will help too, as NO2 makes its harder for fish to transport oxygen to tissues. The chloride ion has greater binding affinity at the gill than NO2, so it will be taken up instead.

Also, do you have enough media or substrate to house a large bacterial population?

The tank is bare bottom but there should be enough media And large pieces of driftwood for the bacteria. Over the past 3-4 weeks I've been raising the hardness. Not quite up to 50ppm yet but it's up to 30 which is a start. Do you think it will take a while for the bacteria to start working again since the hardness was that low? Btw my GH was good. Only the KH was low. I've also been keeping the alkalinity up too. And tank is dosed at 1 teaspoon aquarium salt per 10 gal

 

[jwh]

Have you measured with different test kits?

 

[Empyreal]

not sure what your prob could be, could be tank is not quite done cycling, could be not enof filtration for stock or a combo of both, or rinsing medias in tap water instead of old tank water there by knocking your cycle back. the chemistry is the chemistry, the number are the numbers.

as an FYI between ammonia, nitrite and nitrate , nitrite is the worst for fish. I take it the water is never cloudy?

Wow really? This whole time I always thought Ammonia was most toxic, nitrite less, and nitrate much less, almost safe

 

[Pomatomus]

Wow really? This whole time I always thought Ammonia was most toxic, nitrite less, and nitrate much less, almost safe

This response is long, but detailed and worth reading for most people on this site. This stuff is important to fishkeepers of all skill levels.

You are pretty close. Nitrate isn't as much of a concern for sure, but in high levels it can cause things like goiters (by preventing iodide uptake) and it is well-known as an endocrine disruptor (messing up hormones). It is not acutely toxic in realistic levels for most fish.

As for ammonia vs. nitrite, it depends on the environment. When some chloride is present (e.g. from sodium chloride or calcium chloride) then nitrite is not a big deal. Exactly how much chloride is needed depends on the nitrite concentration and water volume. Saltwater fish will rarely have problems from nitrite poisoning aka "brown blood disease". However, the high pH in saltwater means ammonia can be a real problem.

Ammonia toxicity depends on total ammonia nitrogen (TAN), pH and temperature. Your typical test kit only measures TAN, so it's not the best for determining if your fish will have problems. The toxic form of ammonia is the un-ionized form: NH3. When the pH is low (acidic, more H+ available) then more of the ammonia will be in the ionized form, ammonium (NH4+). So when the water is acidic ammonia is less of a problem. It is also safer at lower temperatures. This leads into the "old tank syndrome" that I mentioned before. When your pH drops low, your bacteria stops working like I said. Then, because they aren't working, ammonia levels rise. However, since the alkalinity (and therefore pH) is so low, most of the ammonia isn't toxic and your fish will act fine. However, if you raise the pH (from buffers or water changes) then more ammonia will be un-ionized and toxic to your fish. This is old tank syndrome. If you do a water change in these conditions, you will probably notice signs of ammonia poisoning in your fish.

I came across a bad case of old tank syndrome when I was called to a lady's house to clean her 29g tank with 6 large, fancy goldfish and a pleco. The pH was 3. The ammonia test read over 5.0. No carbonate (which mostly makes up your alkalinity), which is consumed by beneficial bacteria, that's why it plummeted for the OP). She didn't trust me when I said I had to do a 150% water change (since the store said don't do that much), but if I didn't then she would have lost fish from ammonia. I did the change and even though she doesn't trust me, she lost no fish. I had to fill the tank super slow to acclimate the fish to that pH.

 

[Pomatomus]

The tank is bare bottom but there should be enough media And large pieces of driftwood for the bacteria. Over the past 3-4 weeks I've been raising the hardness. Not quite up to 50ppm yet but it's up to 30 which is a start. Do you think it will take a while for the bacteria to start working again since the hardness was that low? Btw my GH was good. Only the KH was low. I've also been keeping the alkalinity up too. And tank is dosed at 1 teaspoon aquarium salt per 10 gal

Well this kinda leads into an explanation of GH, KH, and alkalinity. But in short, you are taking the right measures.

You need to be raising your carbonate hardness specifically to fix your problem. Carbonate hardness (KH) is just your carbonate concentration. Carbonate is used by your beneficial bacteria, so it will always be decreasing (unless a lot of water evaporates) in a normal tank. It decreases as the bacteria process nitrogen, so basically the more you feed the tank the more carbonate will be used.

Alkalinity is a measurement of the buffering capacity of a solution, or the ability of it to resist changes in pH. The vast majority of our alkalinity comes from carbonate, but things such as phosphate also contribute. A higher alkalinity means that your pH is less likely to drop.

General hardness (GH) is a measurement of metals with a 2+ charge. It's a collection of things like calcium, zinc, and magnesium. It is of little importance to you or your issue right now, as it doesn't really affect nitrification. When you want to keep wild discus we can talk more about adjusting GH!

To answer your question, it could take time or not. If your bacteria totally died then it will be like starting over. However, depending on how long you had this condition the bacteria may be present, but dormant. Either way your population is probably lower than what your bioload needs. Just watch it over time and things should improve.

Phew! I'm tapped out on water chemistry right now. I hope those 2 posts were useful to someone. Ned out.

(Mic drop)

 

[Drstrangelove]

When I added more fish the nitrite went up to .25ppm and since has never gone down.

Assuming everything is being measured correctly (e.g., no bad test kits), and adding the post from June 26 (?) you made...


From the post you made at the end of June (where you said you had been measuring ammonia and nitrites and they were always zero), we can guess that 1) your tank was cycled or 2) your measurements were in error. A test for nitrates (at that time) would have been the test that would validated a conclusion. I don't see that you posted having tested nitrate then or since.

However, it would still be great to see what your nitrates are today. IMO a tank isn't certifiable as cycled unless a significant and growing amount of nitrates is detected (barring some other explanation for where nitrates may be going, e.g., plants.)

Your OP now is that nitrates jumped when you added fish. How many and what size fish did you add? How much and what are you feeding them?

That would be perfectly reasonable IF you had increased the bio load enormously "when you added more fish." Nitrosomonas bacteria multiply much faster than nitrobacter and both multiply differently under varying temperature, salinity, ph, etc.

Despite that, the only explanation I can conjure for why the nitrite "has never gone down" is because food continues to be put into the tank. If nitrites are at .25 all the time, but the fish are being fed, then the amount of food is too much and needs to be reduced until the BB catches up. There must be nitrobacter in the tank, otherwise nitrites would be far higher than .25.

You indicated that you "keep" your pH at 7. I take that to mean that it isn't always at 7, since it's normally not possible to make the pH be exactly one number at all times. If the pH routinely goes below 6.0, for example, the BB cease to reproduce and to process ammonia or nitrites, while at 6.5 they are much less efficient.

The optimal metrics (from 2 studies I found) to grow BB is 7.8 - 8.5 pH and 59-77 F. When conditions differ, it becomes less than optimal. Higher temperatures and lower pH plus a large increase in bioload would, for all intents and purposes, be a mini cycle.

I'd reduce the food level and let the BB catch up with whatever bioload is in the tank.

As for the GH/KH issues, I'm pretty short on info there. I don't recall seeing anyone claim in test that those have an effect on BB. (That of course proves nothing other that I don't if it does or doesn't.) I wonder, not only because BB exists in all sorts of water, but because the water that you have been using before and were using at the end of June (for a month), seemed to be having no effect despite it's GH/KH levels. Still, I will admit I know almost nothing else on the matter. Trying to fix the hardness might help greatly.

 

[knobhill]

Still wondering if op tried a different nitrite test. It could be a faulty reading or bad batch.

 

[Empyreal]

This response is long, but detailed and worth reading for most people on this site. This stuff is important to fishkeepers of all skill levels.

You are pretty close. Nitrate isn't as much of a concern for sure, but in high levels it can cause things like goiters (by preventing iodide uptake) and it is well-known as an endocrine disruptor (messing up hormones). It is not acutely toxic in realistic levels for most fish.

As for ammonia vs. nitrite, it depends on the environment. When some chloride is present (e.g. from sodium chloride or calcium chloride) then nitrite is not a big deal. Exactly how much chloride is needed depends on the nitrite concentration and water volume. Saltwater fish will rarely have problems from nitrite poisoning aka "brown blood disease". However, the high pH in saltwater means ammonia can be a real problem.

Ammonia toxicity depends on total ammonia nitrogen (TAN), pH and temperature. Your typical test kit only measures TAN, so it's not the best for determining if your fish will have problems. The toxic form of ammonia is the un-ionized form: NH3. When the pH is low (acidic, more H+ available) then more of the ammonia will be in the ionized form, ammonium (NH4+). So when the water is acidic ammonia is less of a problem. It is also safer at lower temperatures. This leads into the "old tank syndrome" that I mentioned before. When your pH drops low, your bacteria stops working like I said. Then, because they aren't working, ammonia levels rise. However, since the alkalinity (and therefore pH) is so low, most of the ammonia isn't toxic and your fish will act fine. However, if you raise the pH (from buffers or water changes) then more ammonia will be un-ionized and toxic to your fish. This is old tank syndrome. If you do a water change in these conditions, you will probably notice signs of ammonia poisoning in your fish.

I came across a bad case of old tank syndrome when I was called to a lady's house to clean her 29g tank with 6 large, fancy goldfish and a pleco. The pH was 3. The ammonia test read over 5.0. No carbonate (which mostly makes up your alkalinity), which is consumed by beneficial bacteria, that's why it plummeted for the OP). She didn't trust me when I said I had to do a 150% water change (since the store said don't do that much), but if I didn't then she would have lost fish from ammonia. I did the change and even though she doesn't trust me, she lost no fish. I had to fill the tank super slow to acclimate the fish to that pH.

Thank you so much for taking the time to write that. I learned more in that post than in the past year for fish keeping (and I thought I knew a lot). A pH a 3!? Thats as acidic as the human stomach! Did you burn yourself changing the tank? I've taken many chemistry classes so everything you said makes a ton of sense.