Nitrate In Tap Water 25-30 What Are Options

[clivealive]

hi,
I have Nitrate in my Tap Water 25-30 what are options to lower the Tank Nitrate ?
 
with the starting point of 25-30 its rarely lower than 50 before water change at best.
 
what can I do

 

[Ch4rlie]

First off, a few questions to help work out your options.
 
What is the nitrate readings from your tap / water supply?
 
Do you have live plants in your tank?
 
And what test kit are you using?
 
Nitrate levels of 25 to 30 ppm is actually not bad, pretty normal I'd say, I certainly get that level of nitrates in my low tech 10 gal tank with just a few low tech plants, and all is good.
And i get around 40ppm nitrate straight from my tap water so even if wanted lower nitrate below 40 ppm without any live plants at all, is pretty much an impossibilty.
 
The 3 foot  tank I have, with lots of plants including water lettuce, elodea, vallis and cyrpts plants all are high nutrient consumers, so my nitrate level in that tank is rarely above 5 - 10 ppm.
 
One other thing, the API test kit for nitrate can be a little bit unreliable and misleading due to the fact of there are two bottles of re-agent solutions that needs to be shaken REALLY well to have any real accuracy in nitrate tests.

 

[clivealive]

What is the nitrate readings from your tap / water supply?   25-30 ppm
 
Do you have live plants in your tank?  one plant cant have more as get eaten
 
And what test kit are you using?    king british and API test kit , both show same levels
 
tried water lettuce and they ate it

 

[attibones]

What fish do you have in the tank? This can increase nitrate levels in the tank, too. You could try waxy leaved plants like anubias. Java moss is not usually eaten by most fish. Java ferns are usually safe. They may absorb nitrate at a slower rate, but they do help. 

 

[clivealive]

i only have 1 plant cant have more , so looking for a different solution .

 

[fluttermoth]

Can you tell us exactly what fish and how many you have, and how big your tank is, please?
 
Then we can work out a plan

 

[clivealive]

I have 2 tanks and both have the same issue its not the fish its the tap water level.
tank 1 220L 4ft tank with JD 4" , texas 3 " rainbow cichlids x2 2 " ish , 4 " syno, firemouths x 2 "  so all small ish  (stock wise fine at current sizes)
have purigen in external cleaned water nicely but no affects on nitrate etc as yet.
 
tank 2 120L   2 sajica 2 1/2 " , and 6 other very small fish inc  gold barbs and diamond tetra's and 2 small yoyo loach. ( well under stocked)

 

[fluttermoth]

With those fish, none of which are particularly sensitive, I don't think you need to worry about 50 or 60 ppm nitrate, tbh.

 

[the_lock_man]

Your only other realistic option is to increase your water change frequency, to keep it closer to the 25-30ppm. You don't need it at 0ppm.

 

[Byron]

"Nitrate" is misunderstood within the hobby, and one of the prevalent myths is that ammonia and nitrite are poison but nitrate is basically "safe."  But nitrate is not "safe" at such high levels as are being mentioned here.  The cichlid experts advise keeping it below 20 ppm max, and Dr. Neale Monks writes that there is good reason to believe that cichlids are negatively harmed at levels above 20 ppm long-term.
 
Having said that, there is also some discussion as to just what "nitrate" means when it comes to various tests.  TwoTankAmin has more knowledge of this aspect so I won't attempt to sort it out.  But levels as high as 30 ppm in tap water is considered a health risk, and in NA are prohibited in public water supplies.  It makes sense that fish will be having trouble too.
 
The limited studies with fish and nitrate that have been done to date have proven two things.  First is that fish are definitely negatively affected by nitrate, just as they are by ammonia and nitrite.  But what is not yet fully understood is the exact relation between levels and exposure.  So the second known fact is that the higher the nitrate, and the longer the exposure, the more harm is done to the fish.  Some fish seem more sensitive to this than others.
 
I would certainly not want to be drinking water with nitrates at 25-30 ppm, and I would not keep my fish in the same.
 
To the numbers in post #1...nitrates rising from 30 to 50 between water changes in the aquarium is a sign of a problem in the aquarium.  Either the tank is overcrowded, or there are insufficient water changes, or over-feeding...or all three.  Nitrates should not be rising between water changes to this extent, but more along the lines of 5-10 ppm max.
 
And concerning plants, they will not make a huge dent in nitrates because they do not take up nitrates to the extent that this particular situation will be greatly improved.  Aquatic plants prefer nitrogen in the form of ammonium, not nitrate.  Studies have shown that only when ammonia/ammonium was exhausted did most plants then turn to nitrate.  This is because the plant taking up nitrate has to convert it back into ammonium, and this takes more energy, so it is a last resort of sorts.  In a high-tech method planted tank, yes, plants use more nitrates because they are forced to do so.  But in low-tech or natural systems, as here, they will use the ammonia/ammonium primarily, and this will normally be more than sufficient even in more heavily-planted tanks.  This does help to keep nitrates lower, because the plants grab the ammonia/ammonium faster than bacteria, so less of it is being changed into nitrite and then nitrate.  So plants do help in this sense, but at levels above 20 ppm they are not going to make a difference except in a high-tech system.
 
Byron.

 

[Ch4rlie]

I would certainly not want to be drinking water with nitrates at 25-30 ppm, and I would not keep my fish in the same.

 
Well, for those who have nitrates coming out of tap at around 40ppm, like I do, what can we do to lower the levels of nitrate and exactly, what is the harm in drinking this amount of nitrate for humans?
 
And as for fish tanks, changing water will not make any changes to nitrate levels unless, as far as I know, you have a good level of plants which I always believed consume nitrate.
 
If you can clarify any of this, that would be appreciated.

 

[TwoTankAmin]

Perhaps the most important things to know relative to nitrate have to do with testing for it. It is not easy to test directly do what the hobby kits do is first convert it to nitrite and then measure that. The problem gets worse because the nitrate kits themselves are not all that accurate. Two people can use the same kit on the same tank at the same time and get two different results. The kits are least accurate in the 0-20 ppm range. This can complicate the process of trying to manage nitrate. I believe nitrate kits are best used to indicate directional changes more than absolute levels.
 
Next, there are two different scales used in testing for nitrogenous compounds. One only measures the nitrogen ions present and the other measures all the ions present. Think of it as measuring temperature in C or F. Both scales are accurate and can be converted back an forth. The same applies to the two test kit scales. In general, science tends to use the nitrogen scale and our hobby the total ion scale. What does this mean for nitrate?
 
The EPA in America has set a standard of 10 mg/l Nitrate-nitrogen as the maximum allowable level in tap water. The conversion factor from Nitrate-N to nitrate is 4.43. So that 10ppm of NO3-N should give a reading on a hobby kit of 44.3 ppm of NO3. So the first issue here is one needs to know which scale is being used when we read that X level of nitrate is harmful or safe. I have not seen what scale Dr. Monks is using when he discusses nitrate.
 
The next important consideration is that there is no single number one can use to indicate what level of nitrate might be dangerous or safe for any given fish/inverts. This is very species specific. But then the same applies to ammonia and nitrite as well. Some fish are able to handle nitrate-n levels that are quite high, in the 100s of ppms. Other fish and inverts are sensitive to levels under 5 ppm on No3-N. What this does is make it hard to determine what levels may or may bot be OK in a tank. For some who do higher light co2 added tanks, it is actually necessary to add nitrate for the plants.
 
The real problem with nitrate is not so much what level it is in a tank so much as what level is in one's tap. These provide our base level of nitrate and is really the lowest level we can start with unless we pretreat our water. That can be quite a an issue in some cases. As a rule, the lower one can keep nitrate in a tank, the better off the inhabitants will be. When the primary source of nitrate in a tank is one's tap water, this can make things difficult to manage.
 
In the tank itself we can use several methods for lowering nitrate. As note, live plants can be a big help, but these are not always an option, especially in tanks with plant eating fish or with rift lake cichlids where most plants wont last. Other options need to be explored. One of these could be an veggie filter separate from the main tank and through which the water passes. This is filled with live plants whose job is to remove nitrate. All the space in a veggie filter can be for plants since no fish are in it, so this is not a factor.
 
Another option is to use filtration methods which foster greater growth use of denitrifying bacteria. These are present in every nitrifying biofilm. The question is only one of quantity. But this would require one to change how they filter their tank in some way. Optimizing denitrification requires specific types of media and flow rates and these are not typical of most of the filters we use. Canisters are usually the best for this due to their media holding capacity and lower flow rates than power filters etc.
 
One thing many fish keepers do not realize is how a planted substrate itself naturally creates a denitrifying environment. Here is an example:

Abstract
Nitrogen and 0, transformations were studied in sediments covered by Lobelia dortmanna L.; a combination of lsN isotope pairing and microsensor (0,, NO,-, and NH,+) techniques were used. Transformation rates and microprofiles were compared with data obtained in bare sediments. The two types of sediment were incubated in doublecompartment chambers connected to a continuous flow-through system
.
The presence of L. dortmanna profoundly influenced both the nitrification-denitrification activity and porewater profiles of 02, NO,-, and NH,+ within the sediment. The rate of coupled nitrification-denitrification was greater than sixfold higher in L. dortmanna-vegetated sediment than in bare sediment throughout the light-dark cycle. Illumination of the Lobelia sediment reduced denitrification activity by -30%. In contrast, this process was unaffected by light-dark shifts in the bare sediment. Oxygen microprofiles showed that 0, was released from the L. dortmanna roots to the surrounding sediment both during illumination and in darkness. This release of 0, expanded the oxic sediment volume and stimulated nitrification, shown by the high concentrations of NO,- (-30 FM) that accumulated within the rhizosphere. Both lsN, isotope and microsensor data showed that the root-associated nitrification site was surrounded by two sites of denitrification above and below, and this led to a more efficient coupling between nitrification and  denitrification in the Lobelia sediment than in the bare sediment.

from http/m.m.aslo.info/lo/toc/vol_42/issue_3/0529.pdf
 
There are also a variety of chemical means for dealing with nitrate, but I am not a fan of these as they are an ongoing cost which can become serious when one has multiple and/or large tanks.
 
For those curious, here is one of the few articles I have found on nitrate and fish. it is an real interesting read. if you read it, be sure you consider the species mentioned. The fish and inverts most sensitive to nitrate in that article are ones you will almost never see in hobby aquariums.
http/www.researchgate.net/profile/Alvaro_Alonso3/publication/8063535_Nitrate_toxicity_to_aquatic_animals_a_review_with_new_data_for_freshwater_invertebrates/links/543f9e150cf2f3e82851e42d.pdf
 
 
 
 

 

[Essjay]

TTA, if it is any help, water companies in the UK use the DWI (drinking water inspectorate) standards. Looking at my water quality report it says that nitrate has the DWI parameter code AD12 and the upper limit is "50 mg/l as NO3 ". Does that tell you which scale they use?
 
There is also a value for "nitrate nitrite formula" which is code AD13C and has a maximum allowed upper limit of "1mg/l as NO2". Nitrite itself is code AD13A with a max allowed of "0.1mg/l as NO2"

 

[Byron]

 

I would certainly not want to be drinking water with nitrates at 25-30 ppm, and I would not keep my fish in the same.

 
Well, for those who have nitrates coming out of tap at around 40ppm, like I do, what can we do to lower the levels of nitrate and exactly, what is the harm in drinking this amount of nitrate for humans?
 
And as for fish tanks, changing water will not make any changes to nitrate levels unless, as far as I know, you have a good level of plants which I always believed consume nitrate.
 
If you can clarify any of this, that would be appreciated.
 

 
I'll offer what I can.  TTA has provided the technical aspect that I had hoped he would (thanks TTA).  He also corrected my numbers for safe drinking water.  As for the effects of high nitrate on humans, I know one of these has to do with a developing fetus in pregnant women, and this is serious; related, I have come across dangers for young children more than adults.  One should be able to find data on all this online.  Fortunately, I have zero nitrates in my water.  And this means I have not delved into the methods for dealing with this, but I have read suggestions from members here and elsewhere, who would be more able to answer this point.
 
I can offer more on the second question.  First, as I said, the majority of aquarium plants do not take up nitrate unless ammonia/ammonium is unavailable for their purposes.  In controlled tests, Elodea nuttallii had removed 50% of the available ammonium within 8 hours, but very few nitrates; only after 16 hours when most of the ammonium was gone did the plant begin to take up nitrates.  The uptake of ammonium is much quicker too.  Pistia stratiotes was found to take up ammonium in 4 hours, while it required 20 hours to take up nitrate.  Both of these studies, and there are many others, show that ammonium uptake is preferred and faster.  And as I mentioned previously, this results in less nitrite and thus less nitrate depending upon the number and species of plants.  Many of us with fairly heavily-planted tanks can test and find zero nitrates on a regular basis.
 
As for the water changes, these do and will significantly reduce nitrates if the nitrates are occurring within the aquarium, meaning, as a result of the fish and feeding them.  This is why over-stocked tanks or over-fed tanks have (or can have) high nitrates and require substantial water changes.  The danger of course is that a missed water change can be deadly to the fish, so the stocking should not push the envelope, so to speak, just in case.
 
And that brings me to TTA's referenced study.  A nitrate (here it is NO3-N) level of 10 mg/l (= 10 ppm) can adversely affect several species, and this is the maximum level allowed by US law in public water systems.  According to TTA's calculation numbers, this would be 40 ppm with an API nitrate kit.  I have no idea which scale Dr. Monks' is using when he repeatedly advises in PFK that nitrates be kept no higher than 20 ppm, but I would assume the API type as he is dealing with hobbyists.  I will attempt to ascertain this and report further.
 
As I mentioned earlier, the data is not exhaustive, but what has been done certainly shows that the higher the nitrates, and/or the longer the exposure period, the more detrimental to all aquarium fish, although in varying degrees to specific species.  The detrimental effect of nitrates should not be at all surprising, when one remembers that in the natural waters in which all our fish originally occur, the nitrate level is rarely as high as 1 or 2 ppm, and that is not much.  It makes as much sense to me for someone to say that fish can over time adapt to higher nitrate, as it would to say they can adapt to high ammonia or nitrite too.  They obviously cannot.
 
Byron.

 

[TwoTankAmin]

essjay- I would assume it is measured using the total ion scale. 50 ppm of NO3-N would show up on an API type test kit as 220 ppm. I cannot imagine this would be considered safe.
 
The biggest danger to humans from nitrate in tap water is, as Byron noted, is for infants. It ls also very bad for people on dialysis.
 
The other part of all this is how nitrate harms fish, Everything I have read says it does so in a similar fashion to Nitrite. That means it block the blood from carrying oxygen. The reason why nitrate is considered less toxic than nitrite is similar to why with ammonia NH3 is far worse than NH4. It has to do with the ability of these things to pass through the barriers in fish gills. The larger the size, the less easily it can pass though. NO2 can enter much easier than NO3 so it takes more NO3 being in the water to produce a given effect.
 
For those reading the study, note that some fish seem able to handle off the charts nitrate for quite some time. Most of the research one can find on nitrate toxicity will focus on one of two areas. The first is in natural settings- streams. lakes, ponds rivers etc. Here the concern is for the most sensitive species. The second area is aquaculture. When fish are being farmed for profit, anything that can hurt profits by hurting the fish is important.
 
I am not prepared to state with any certainty what the red line level for nitrite might be the way I might for ammonia. What I can say without any doubt is that lower is always better. I also know if one really wants to measure nitrate accurately, use a much better test than is available in hobby kits. A decent Hach color disc test kit runs about $90. Really accurate lab grade probes for digital testing run in the $700s and the really serious stuff runs into the many $1,000s. At the very least, I would want to use Hach test strips for nitrite and nitrate
which runs about $25 delivered and is good for 25 tests. I can buy the API 90 test nitrate kit for about $7.