🌟 Exclusive 2024 Prime Day Deals! 🌟

Unlock unbeatable offers today. Shop here: https://amzn.to/3LmzcqW 🎁

Very high Nitrates even after major water changes

With enough live plants you are unlikely to ever experience an ammonia spike, even if the filter fails.
I once forgot to turn my filter on after a water change and only discovered at the following week's water change. The water contained zero ammonia and nitrite. I have live plants, mainly slow growing ones, but I do have floating plants, which are often referred to as ammonia sinks.

Floating plants are very good at removing ammonia because they have the other two requirements - light, as they are close to the tank lights; and carbon dioxide from the air, which holds more than water. There are several types of floating plants in the hobby, and anacharis stems can be left floating. If you don't want live plants rooted in the substrate, floating plants on the surface will help enormously.
 
Yes, plants are usually a benefit, but not all tanks and fish have or work with live plants. For such tanks that leaves two options, a separate veggie filter or working 100% with microorganisms.

But let us not forget that plants also host nitrifying bacteria. So there is more going on than just plants. One cannot have a planted tank with no cycling bacteria/Archaea no matter how many plants there are. On the other hand one can have a fully cycled tank with zero plants. I know because I have 12 of my 19 running tanks with no plants at all and I just took down a 125 which also never contained a single plant.

My unplanted tanks are all related to breeding and growing out plecos. There is minimal ambient room light and there is almost 0 natural light as well. The one time there is decent light going into any of these tanks is when I do maint. on them. One note on this. A few of these tanks have Hamburg Mattenfilters and the rest have an excess of Poret foam cubefilters. I have huge amounts of thick foam media. Once established these tend to develop the kind of bacteria than can function one way when oxygen is available but another way when the oxygen is not but nitrate is, they switch to using the nitrate and that produces N2 gas which leaves the tank. Another name for this process is denitrification.

There is one wild card in this all, algae. Algae uses ammonia, but there is also a caveat here. When ammonia levels are really elevated it has the reverse effect on algae, it does not grow as well. So in the average established tank you can get a lot of algae. But if one has a cycling issue and ammonia spikes for a bit, it will act to retard algal growth.
 
Well I am stumped. I did an 80% water change today and tested my water after, still 160 ppm Nitrate.
Took my HOB filter apart to see if there was any rotting snails, found a couple. Removed them.
Cleaned every square inch of gravel with a gravel syphon. Source water tested 0 ppm Nitrate.
Never added Tetra EasyBalance Plus or Nutrafin Cycle either.
Doing the test exactly as the instructions say...
Fill the tube to the 5mL mark with tank water.
Add 10 drops of Nitrate solution #1. Shake tube several times.
Shake Nitrate solution #2 for 30 seconds.
Add 10 drops of Nitrate solution #2.
Shake tube for 1 minute
Let stand 5 minutes.
 
For example: Since the test maximum is 160ppm, if your real nitrate level is 6400ppm, it will take at least 6 time 50% water changes before it registers under 160ppm. (It's an inflated example, but it demonstrate clearly the principle.)

Take half a gallon of tank water and another half gallon of tap water, blend it and run the test if the test still show 160 dilute it in half one more time, run the test, continue until you are able to register under 160ppm

Then multiply 160 by the number number of times you cut the water in half and it will give you your "Real level"

If the test continues to register 160ppm all the time after a couple dissolution, I would get another one to corroborate these results.

If the new test backs up what you already have... You need to continue water changes until it rinses off.

I never experienced a snail extinction level event. But I'm positive that it must create an incredible amount of ammonia.

And the fact that your filter was coping with it so well, is just amazing.
 
You need to do more than shake the #2 bottle. it is notorious for the solids to precipitate out of solution, sink to the bottom and coagulate there. You need to bang the bottl on a hr surface, shake it like mad for 30 seconds, bang it again a couple of time and shape it violently some more.

When you remove water from the tank to test, do not take it from the surface. Try to take further down from the surface. You can do this by inverting the container ot test tube and submerging it. The turn it ove and it fill with lower level sample water. You can then pout back (or out) the excess.

Diluted testing will work. But you do not need 1/2 gal of water to do diluted testing. 1/2 cup amounts work fine. Start with a larger clean container and add 1/2 cup of tank and 1/2 cup of tap and test that using the normal test tube filled to the 5 ml line. If the reading is under 160 ppm then multiply it by 2 to get the actual ppm.

If it is still reading 160, add another 1/2 cup of tap water to the mix and retest (rinse the tube between tests). If the result of this 2nd test isunder 160 ppm, multiply it by 3 to get you actual ppm.

If it is still not under 160 ppm after the second test, then add one more 1/2 cup of tap water to the mix and restest using the runsed out tube. If this result is under 160 ppm, multiply the result by 4 to get the actual ppm.

Until you do get a result under 160ppm continue to add 1/2 cups of tap increasing the multiplying number by with each addition until you do get a reading under 160.

A part of the problem here is organic matter doesn't break down instantly, it does so over time releasing and ongoing amount of ammonia The bacteria for ammonia and nitrite will reproduce when there is more of these things than they need to thrive.

I will be surprised if you need to do more than one or two diluted tests. I think the issue is not how high the nitrate is as much as how long it will take for the excess organics to break down and end up as nitrate.

if you know somebody with healthy tanks and like plants, if you can get/buy some of their excess or cuttings of stem plants, these will help as they should be able to use nitrate to some extent. Also, when they use ammonia (as ammonium), they do not make nitrate from it.

edited for typos
 
Last edited:
You need to do more than shake the #2 bottle. it is notorious for the solids to precipitate out of solution, sink to the bottom and coagulate there. You need to bang the bottl on a hr surface, shake it like mad for 30 seconds, bang it again a couple of time and shape it violently some more.

When you remove water from the tank to test, do not take it from the surface. Try to take further down from the surface. You can do this by inverting the container ot test tube and submerging it. The turn it ove and it fill with lower level sample water. You can then pout back (or out) the excess.

Diluted testing will work. But you do not need 1/2 gal of water to do diluted testing. 1/2 cup amounts work fine. Start with a larger clean container and add 1/2 cup of tank and 1/2 cup of tap and test that using the normal test tube filled to the 5 ml line. If the reading is under 160 ppm then multiply it by 2 to get the actual ppm.

If it is still reading 160, add another 1/2 cup of tap water to the mix and retest (rinse the tube between tests). If the result of this 2nd test isunder 160 ppm, multiply it by 3 to get you actual ppm.

If it is still not under 160 ppm after the second test, then add one more 1/2 cup of tap water to the mix and restest using the runsed out tube. If this result is under 160 ppm, multiply the result by 4 to get the actual ppm.

Until you do get a result under 160ppm continue to add 1/2 cups of tap increasing the multiplying number by with each addition until you do get a reading under 160.

A part of the problem here is organic matter doesn't break down instantly, it does so over time releasing and ongoing amount of ammonia The bacteria for ammonia and nitrite will reproduce when there is more of these things than they need to thrive.

I will be surprised if you need to do more than one or two diluted tests. I think the issue is not how high the nitrate is as much as how long it will take for the excess organics to break down and end up as nitrate.

if you know somebody with healthy tanks and like plants, if you can get/buy some of their excess or cuttings of stem plants, these will help as they should be able to use nitrate to some extent. Also, when they use ammonia (as ammonium), they do not make nitrate from it.

edited for typos
Alright I mixed 1 cup of tank water with 1 cup of tap water. Nitrate went down to 20 ppm ( 20 ppm and 10 are hard to tell apart according to the color chart - they are very similar in color). I added another cup of tap water and it went down to 5 ppm Nitrate.
I guess I just of to keep doing huge water changes...
Could I use tap water with conditioner? My tap water tests 4 ppm ammonia though... It is not easy hauling 7 5 gallon water jugs from the store.
My city says they add ammonia to get chloramine.
 
Last edited:
One thing to consider is that when the nitrate test is done improperly it tends to show less nitrate than is actually there. What are you using for substrate, fertilizer, etc. with the high levels you are talking about the nitrates might be coming from something in the tank, not just from the breakdown of organic material.
 
How does the hardness of your tap water compare to your re-mineralised RO?
 
You only needed to do the first diluted test because after it you knew you had 20 ppm x 2 = 40 ppm. All you needed to do was one more big water change and the hitrate should gave dropped below 20 ppm.

But, you did another diluted test and 5 ppm x 3 = 15 ppm. Again a good number but one which would not suggest you needed to do another water change at all.

I am concerned about the ammonia level of 4 ppm in your tap. The US does not set standards for ammonia in drinking water. Imo that is a failing on their part. The National Academy of Science recommends a drinking water standard of 0.5 ml/l (that is 0.5 ppm). In 1990 the EPA issued a lifetime exposure advisory of 30 mg/l (30 ppm).

So are you certain of the ammonia reading? That is a pretty high level. However, the good news is in your tank it is mostly ammonium (NH4) which is way less toxic than ammonia (NH3). I used 77F as your temp and the 7.2 pH you reported and ran the numbers. The amount of NH3 in your 4 ppm Total Ammonia reading is only 0.0364 ppm. The cut off point I use for that harming fish is 0.05 ppm and many fish can handle a bit higher for some time.

But, the 4 ppm of ammonia in your tap can become a lot of nitrate. So I think we have figured out the cause. Between the ammonia from your tap and the rotting dead snails- this is he reason for such high nitrate.

Chloramine is created by mixing chlorine and ammonia. When we use dechlor it breaks apart the bond between those two components and then detoxifies the chlorine component. However, most of the popular dechlors also detoxify ammonia. They basically turn it into ammonium. The bacteria can still process this, but less efficiently. This is normally not a big deal because the ammonia levels are not as high as you are reporting.

What normally happens in a cycled tank is there is sufficient bacteria to process the ammonia component and because it is NH4 and it is less harmful to the fish and also gone fairly fast.

So, where does this leave you? Basically, if the 4 ppm persists you will need to take some action to mitigate this as it will make you life easier. There are a couple of ways to do this. One is to alter tou water changing schedule. Instead of doing a single large change, you can do 2 or 3 smaller changes. This will effectively reduce the ammonia concentration after the change making it easier for the bacteria to clear it.

Another path is to start using some live plants. They will consume the ammonium and do so faster than the bacteria. You can use plants which go in the substrate or in pots with substrate. You can do floating plants which work well and many of the stem plants can be floated. They are usually faster growing and less expensive.

Finally, you can use RO or RO/DI water to some extent. However, this means you will be "messing" with your tap water chemistry. Doing this in a stable way is a fair amount of work and may require additional digital equipment to be able to monitor things adequately so you can then manage parameters. I would suggest that this is the least appealing option. You will need to learn more of the science involved with water parameters and changing them in the proper way.
 
You only needed to do the first diluted test because after it you knew you had 20 ppm x 2 = 40 ppm. All you needed to do was one more big water change and the hitrate should gave dropped below 20 ppm.

But, you did another diluted test and 5 ppm x 3 = 15 ppm. Again a good number but one which would not suggest you needed to do another water change at all.

I am concerned about the ammonia level of 4 ppm in your tap. The US does not set standards for ammonia in drinking water. Imo that is a failing on their part. The National Academy of Science recommends a drinking water standard of 0.5 ml/l (that is 0.5 ppm). In 1990 the EPA issued a lifetime exposure advisory of 30 mg/l (30 ppm).

So are you certain of the ammonia reading? That is a pretty high level. However, the good news is in your tank it is mostly ammonium (NH4) which is way less toxic than ammonia (NH3). I used 77F as your temp and the 7.2 pH you reported and ran the numbers. The amount of NH3 in your 4 ppm Total Ammonia reading is only 0.0364 ppm. The cut off point I use for that harming fish is 0.05 ppm and many fish can handle a bit higher for some time.

But, the 4 ppm of ammonia in your tap can become a lot of nitrate. So I think we have figured out the cause. Between the ammonia from your tap and the rotting dead snails- this is he reason for such high nitrate.

Chloramine is created by mixing chlorine and ammonia. When we use dechlor it breaks apart the bond between those two components and then detoxifies the chlorine component. However, most of the popular dechlors also detoxify ammonia. They basically turn it into ammonium. The bacteria can still process this, but less efficiently. This is normally not a big deal because the ammonia levels are not as high as you are reporting.

What normally happens in a cycled tank is there is sufficient bacteria to process the ammonia component and because it is NH4 and it is less harmful to the fish and also gone fairly fast.

So, where does this leave you? Basically, if the 4 ppm persists you will need to take some action to mitigate this as it will make you life easier. There are a couple of ways to do this. One is to alter tou water changing schedule. Instead of doing a single large change, you can do 2 or 3 smaller changes. This will effectively reduce the ammonia concentration after the change making it easier for the bacteria to clear it.

Another path is to start using some live plants. They will consume the ammonium and do so faster than the bacteria. You can use plants which go in the substrate or in pots with substrate. You can do floating plants which work well and many of the stem plants can be floated. They are usually faster growing and less expensive.

Finally, you can use RO or RO/DI water to some extent. However, this means you will be "messing" with your tap water chemistry. Doing this in a stable way is a fair amount of work and may require additional digital equipment to be able to monitor things adequately so you can then manage parameters. I would suggest that this is the least appealing option. You will need to learn more of the science involved with water parameters and changing them in the proper way.
I went ahead and used my tap water for the water change today. My conditioner of choice was Seachem Prime. Just seems like the best option available to me.
These are the parameters of my tank water now:
pH: 7.6
Ammonia: 0.5 ppm
Nitrite: 0ppm
Nitrate: 5ppm
 
Prime binds the ammonia as ammonium which is less toxic. At .5 ppm your bacteria should clear it fairly fast. The pH has risen which makes any ammonia reading more toxic in the absence of Prime. Here are two of the Prime FAQs from the SeaChem site.

I tested my tap water after using Prime® and came up with an ammonia reading. Is this because of chloramine? Could you explain how this works in removing chloramine?

A: Prime® works by removing chlorine from the water and then binds with ammonia until it can be consumed by your biological filtration (chloramine minus chlorine = ammonia). The bond is not reversible and ammonia is still available for your bacteria to consume. Prime® will not halt your cycling process.
and

How long does Prime® stay bound to the ammonia, nitrite, and nitrates?

A: Prime® will bind up those compounds for up to 48 hours. If they are still present after that time frame, they are released back into the water, unless Prime® is re-dosed accordingly. Also, if your ammonia or nitrite levels are increasing within a 24-hour period, Prime® can be re-dosed every 24 hours.

Your numbers now look good. You should retest your tap for ammonia over the next few weeks. Once or twice a week is enough. I am thinking you may see a drop in the ammonia level for incoming tap water.
 
Prime binds the ammonia as ammonium which is less toxic. At .5 ppm your bacteria should clear it fairly fast. The pH has risen which makes any ammonia reading more toxic in the absence of Prime. Here are two of the Prime FAQs from the SeaChem site.


and



Your numbers now look good. You should retest your tap for ammonia over the next few weeks. Once or twice a week is enough. I am thinking you may see a drop in the ammonia level for incoming tap water.
Thanks a lot for the help. Now hopefully my pleco will be alright. He has some white stuff on him and doesn't seem to move very much or eat. The red tail shark seems happy tho.
20240201_161542.jpg
 
Plecos are territorial and they need places to hide. Do you have a cave for it? The tank looks pretty bare. I breed a lot of plecos and their tanks are crowded with wood, rocks and caves.

If I have your pleco properly identified it appears to be a Pterygoplichthys pardalis. Have a read on Planetcatfish here. If I am correct the fish has a max size of "423mm or 16.7 SL" SL meeans standard length which does not count the tail fin in the length. Figure that means about 17 inches give or take.
https://www.planetcatfish.com/common/species.php?species_id=88

The pic makes the tank look pretty bare. The fish will not be happy living that way which will make it more susceptible to illnesses.
 
Plecos are territorial and they need places to hide. Do you have a cave for it? The tank looks pretty bare. I breed a lot of plecos and their tanks are crowded with wood, rocks and caves.

If I have your pleco properly identified it appears to be a Pterygoplichthys pardalis. Have a read on Planetcatfish here. If I am correct the fish has a max size of "423mm or 16.7 SL" SL meeans standard length which does not count the tail fin in the length. Figure that means about 17 inches give or take.
https://www.planetcatfish.com/common/species.php?species_id=88

The pic makes the tank look pretty bare. The fish will not be happy living that way which will make it more susceptible to illnesses.
Yes I had everything removed to clean the gravel very well. I have lots of hiding spots and drift wood for him. I am now looking into adding live plants as well, after learning the benefits of them.
 

Most reactions

Back
Top