# Nitrates and Nitrites Levels



## griffk (Apr 10, 2011)

First of all a description of my tank in question. It's a 75 gallon, running two canister filters one is a fluval and one is an off brand. The fluval is filtering 200 gallons per hour and the off brand 375 gallons per hour. I do weekly 25 Percent water changes. My filters have both been cleaned in the last month, using guidelines I found on here or the tropical fish keeping site, using water from the aquarium, etc. My tank is far from overstocked and has been up and running for around a year. The water is crystal clear, I also run 2 powerheads and a volcano light which helps in adding oxygen to the tank. I just checked my nitrates and they were at 80ppm and my nitrites were at 0.5. What should I do, other than my weekly water changes to bring these levels down?


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## Aulonocara_Freak (May 19, 2011)

Only 25%? I do, and most other people on the forum, do 50% water change's on all there tank's. I recommend doing 20-30% water change's each day, then 1 time a week do a 50% water change until you have nitrite's at 0 and nitrate's below 20.


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## Robin (Sep 18, 2002)

Agree with above. Once your nitrates get 'up there' it takes a lot of water changes to get them down. 
You may be over feeding your fish and that has contributed to the high nitrates. Most fish do best with a once a day feeding, giving them only as much food as can be consumed in less than a minute. Fasting them one day a week is also a good idea. Also if you don't routinely siphon the gravel waste can build up there, especially if your gravel is deeper than 3 inches and that can cause nitrates to rise.

And there's always the possibility that your test kit is faulty. Make sure it's relatively new and generally speaking the test TUBE type of test kit is more reliable than the test strip.

Robin


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## griffk (Apr 10, 2011)

I follow the guidelines directly from this forum. This is the direct quote from Cichlid-Forum. "As a general guideline, you could start with a 20-30% water change once a week. Some people prefer to do a larger change less frequently, such as 40-50% every two weeks. I believe the latter is less desirable since the water chemistry changes more dramatically at once, putting more stress on the fish. Alternately, if your bio-load (ratio of fish to water volume) is low and you donÃ¯Â¿Â½t overfeed, you may be able to do a smaller water change less frequently and still maintain good water quality". I will probably try the smaller water changes more frequently, but I've killed fish doing a 50% water changes. But thanx for the advice.


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## griffk (Apr 10, 2011)

Robin said:


> Agree with above. Once your nitrates get 'up there' it takes a lot of water changes to get them down.
> You may be over feeding your fish and that has contributed to the high nitrates. Most fish do best with a once a day feeding, giving them only as much food as can be consumed in less than a minute. Fasting them one day a week is also a good idea. Also if you don't routinely siphon the gravel waste can build up there, especially if your gravel is deeper than 3 inches and that can cause nitrates to rise.
> 
> And there's always the possibility that your test kit is faulty. Make sure it's relatively new and generally speaking the test TUBE type of test kit is more reliable than the test strip.
> ...


I'm starting to wonder if my test strips are faulty, after you stated this, I currently have 6 tanks. I'm using a strip that tests nitrates, nitrites, hardness, total alkalinity, and PH, three of my tanks are african cichlids, so i keep the PH high, and the other three are south american cichlids, and a community tank, so i keep their water more soft a acidic. With these strips I get the same nitrite and nitrate readings, while the PH reads differently in the african and south american tanks. So Could it be possible I'm not getting a true reading. Do you also recommend a 50% water change weekly? One more thing, when I do a water change I vacuum the gravel with one of the aqueon water changers, so it's not a big deal to do water changes the correct way. Thanx for the response.


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## Number6 (Mar 13, 2003)

If you killed fish with a 50% water change, then you are very likely harming them to some degree with a 10 or 25% change. 
I would suggest you need to prepare your new water more than you currently do. What do you add to the water and what is the GH and KH or your tank and tap water?


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## griffk (Apr 10, 2011)

KH in tank- 180
KH from tap- reading is between 180-300 range

GH in tank- 150
GH from tap- 200

All I do is add dechlorinator and aquarium salt and buffer to my african tanks.

I'm currently running a 165, 2-75's, 2-30's and a 1 gallon. So i'm not gonna lie my water comes straight from the tap.


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## Aulonocara_Freak (May 19, 2011)

What type of declorinater are you using?


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## griffk (Apr 10, 2011)

Aulonocara_Freak said:


> What type of declorinater are you using?


"Top Fin", came from Jack's pets.


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## griffk (Apr 10, 2011)

Ammonia shows up at .05ppm which my test kit says is ideal. Don't know how much this has to do with nitrates and nitrites.


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## Aulonocara_Freak (May 19, 2011)

Ammonia should be at 0. Any Top Fin is a PETSMART brand, what I suggest do is put the declorinater in the water be4 you but it on the tank. Wait 15 minute's be4 putting the decorinated water into the aquarium.


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## griffk (Apr 10, 2011)

Alrighty! Thanx


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## Robin (Sep 18, 2002)

And if you did a 50% water change after not having done a water change in _awhile_ then you _might have_ caused something known as Old Tank Syndrome. Without a water change over time your ph will drop and any ammonia that is present is converted into a non-toxic form. Then when you do a water change if the new water is a higher ph then the ammonia will instantly convert back to it's toxic form and your fish may die--fast. The larger the water change, the worse it will be. 
Also if you did the large partial water change without using a dechlorinator and your tap water is high in chlorine or chloramines then this would have also stressed your fish. 
And one more possible problem with doing a large partial water change is if there is something amiss with your tap water, (say if the water company is working on the lines or there's been flooding in your area that could have affected the water supplies).

Usually a large partial water change is a good thing, but there are some instances where you're better off doing smaller, more frequent partial water changes.

If you're using products to keep your ph up or down, this can also cause problems with your water conditions.

If your nitrate levels are consistently below 20ppm(before water changes) then you can be reasonably certain that you're not overfeeding and that your water changing routine is working.

Robin


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## Nodalizer (Nov 7, 2011)

griffk said:


> I do weekly 25 Percent water changes. My filters have both been cleaned in the last month, using guidelines I found on here or the tropical fish keeping site, using water from the aquarium, etc.


I know its confusing, but a weekly change of 25% will result in high nitrates, even though you have been recommended to do it, I will explain.

Each time you change the water (any amount) you are left with some nitrates in the water, this then added to the new nitrate from the next week means next time you test the tank the nitrates will be higher again.

This will keep adding up until they are out of control like you have now. So what to do ?

You need to do a bigger water change every time you see the nitrates getting to high. Too high would be more then 15-20pmm. After that big water change just go back to your normal water changes.

The size of the bigger water change depends on how out of control they got. I would say 50% would be a big enough water change for a nitrate balance on a tank that does weekly changes of 25%.



griffk said:


> I will probably try the smaller water changes more frequently, but I've killed fish doing a 50% water changes.


If you kill fish doing a large water change it can be because of a number of things, but most likely you have a lot of stuff in your substrate that is not getting vacumed up each water change, when changing the water, it needs to be big enough to allow you to get all of the mess out of the substrate.

When you add the big amount of water and it stirs up all the mess you left behind on previous cleans it would create an ammonia spike, which will kill fish. This is not the water changes fault but not cleaning properly the last few times.



griffk said:


> and my nitrites were at 0.5. What should I do, other than my weekly water changes to bring these levels down?


I would say your nitrite problem is because of what I said above, I think you are not cleaning the bottom of your tank properly, and each water change you are causing an ammonia spike which will need to higher nitrites.

High nitrites can stop or kill the benifitial bacteria that convert that nitrite to nitrate. You will need to get that nitrite down with water changes (now, not weekly), as many as is needed IMO.

I hope that helps.


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## Robin (Sep 18, 2002)

Every tank is different. How much water you remove and how often you do water changes depends on the bioload of the tank. One fish in a 75 gallon is not going to produce the same waste as 10 or 20 fish in a 75 gallon. ANd if you have a tendency to overfeed then even though you may have very few fish you could see your nitrates creeping up. 
So for some tanks a weekly 25% water change may be fine. The only real way to be sure is to test for nitrates just before you do your water change. If they've creeped up over 20ppm then you know you've got increase either the frequency or amount--or both and also look at how much you're feeding your fish.

Obviously the weekly 25% was NOT enough in this situation. Every tank is different. Gotta test. 

Robin


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## Nodalizer (Nov 7, 2011)

I think you missed the point of my post. I wasn't talking about amount or frequency. I was talking about nitrate creep, which happens in EVERY tank, and we fix almost second nature, but someone having problems needs to know this effect will happen and account for it.


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## Robin (Sep 18, 2002)

:thumb: 
Robin


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