High nitrates

[Drstrangelove]

Here's what I wrote:

"1) If you don't over stock a tank
2) if you keep up with WC
3) if you don't over feed your tank
4) if you have things like pothos or purigen"

if your tap water averages 5 ppm how would water changes reduce nitrates any lower , plus those test results are averages ? If your tap water is 1PPM nitrate how would a water change reduce levels below or near unless water change is 100%?as long as water is not changed out 100% (which most of us don't), nitrates will keep increasing as time goes by.

Water changes do not control nitrate, but only slows down the rate of increase.

Here's what your post appears to focus on:

2) if you keep up with WC

So let me repeat my other 3 points:

1) If you don't over stock a tank
3) if you don't over feed your tank
4) if you have things like pothos or purigen

Many people keep their nitrates under 5 ppm. Instead of acting like it's not possible (which is obviously untrue), maybe the better response is to try to understand how it's possible,


1) Nitrates come from food. The less fish you have, the less food you need. The less you over feed, the lower the protein content, the lower the nitrates.
2) Nitrates build up in the water from food conversion. Plants and suitable items (e.g., purigen) can "fix" the nitrates. (Fix meaning remove it from the water in a temporarily stable form.) These items can then be removed later to permanently remove the nitrate from the system.

The system is only a "closed loop" if the pet owner refuses to manage it and simply dumps food and walks away week after week. Then indeed that's a closed loop system.

The correct answer to having and maintaining a daily level below 5 ppm is to have---enough purigen (or something like it), enough denitrification, enough pothos (or other plants), or enough daily water changes to remove the daily amount of nitrates added to the tank. That's essentially what nature does. Water changes are useful to control nitrates if the amount removed daily (by other means) falls short. Water changes by themselves will not control growth in nitrates unless the amount of nitrate removed by water changes equals the amount added, which means large scale water changes.

There are many reasons to do water changes besides due to nitrate buildup. But water changes for the purpose of controlling nitrates don't need to be done at all if the system is balanced. For instance:

------Daily: add 5 ppm nitrates (from food) minus 3 ppm nitrates (pothos) minus 2 ppm nitrates (purigen) = 0 ppm nitrates change----

Using a drip water change system with large daily changes using zero or nearly zero nitrate water can of course also help achieve very low rates, but much less water can be used to achieve the same low rates if used in conjunction with other tools.

 

[decoy50]

+1 to DrStrangelove. My nitrates stay close to 5 in an overstocked 150gal. 0 nitrates in my tap though, so I'm lucky with that. I do 3 50% WCs a week, down from 4 WCs weekly. If WCs are such a hassle or torture, search some of the many threads on this site on how to make them more manageable. I use pumps to add/remove water & can do a 50% change in 30mins while I watch tv.

Nitrates are one of the leading causes of HITH. SA cichlids are the least tolerant of high nitrates. HITH can develop in some sensitive SAs at 20+PPM. WCs are the best thing you can do for your fish.

 

[Mr Pleco]

Here's what I wrote:

"1) If you don't over stock a tank
2) if you keep up with WC
3) if you don't over feed your tank
4) if you have things like pothos or purigen"



Here's what your post appears to focus on:

2) if you keep up with WC

So let me repeat my other 3 points:

1) If you don't over stock a tank
3) if you don't over feed your tank
4) if you have things like pothos or purigen

Many people keep their nitrates under 5 ppm. Instead of acting like it's not possible (which is obviously untrue), maybe the better response is to try to understand how it's possible,


1) Nitrates come from food. The less fish you have, the less food you need. The less you over feed, the lower the protein content, the lower the nitrates.
2) Nitrates build up in the water from food conversion. Plants and suitable items (e.g., purigen) can "fix" the nitrates. (Fix meaning remove it from the water in a temporarily stable form.) These items can then be removed later to permanently remove the nitrate from the system.

The system is only a "closed loop" if the pet owner refuses to manage it and simply dumps food and walks away week after week. Then indeed that's a closed loop system.

The correct answer to having and maintaining a daily level below 5 ppm is to have---enough purigen (or something like it), enough denitrification, enough pothos (or other plants), or enough daily water changes to remove the daily amount of nitrates added to the tank. That's essentially what nature does. Water changes are useful to control nitrates if the amount removed daily (by other means) falls short. Water changes by themselves will not control growth in nitrates unless the amount of nitrate removed by water changes equals the amount added, which means large scale water changes.

There are many reasons to do water changes besides due to nitrate buildup. But water changes for the purpose of controlling nitrates don't need to be done at all if the system is balanced. For instance:

------Daily: add 5 ppm nitrates (from food) minus 3 ppm nitrates (pothos) minus 2 ppm nitrates (purigen) = 0 ppm nitrates change----

Using a drip water change system with large daily changes using zero or nearly zero nitrate water can of course also help achieve very low rates, but much less water can be used to achieve the same low rates if used in conjunction with other tools.

Lets say for sake of discussion an aquarium produces 10 PPM of nitrates a week. ( a week being defined as 5 days) …lets refer to PPM as units

scenario:

once a week (every 5 days) water change of 50 % assuming no nitrates in tap water.After water change you have a tank with 5 units of nitrates. ( 50% of the original 10 units)

Next week when you go to change water again in 5 days you have 15 units ( 5 remaining and 10 new) of nitrates in the aquarium . change 50 % of water … after water change you then have 7.5 units

You can see the longer a tank is set up, the harder it is to maintain low nitrates levels through water changes of less than 100 % , alone.

When your taking care of 1000 gallons of aquarium at 50% per week thats 500 gals a week..

My next question is how much pothos would it take to reduce aquarium water nitrates by 2 units per week? how would you even measure that ?even by subtracting 2 units every week , your nitrate levels at 50% W/C are climbing.

Then add to the fact your tap water has nitrate levels ..? it just doesn&#8217;t make sense to me to worry about levels <100 ppm.

My definition of a &#8220;closed loop system&#8221; is an aquarium with out an auto drip exchanger&#8230;.

After years of being on these forums and taking care/breeding rare fish . I am skeptical of these pristine water quality results. You know the posts Im referring too , "my water is perfect 0ppm AMM, 0ppm Nitrites and 0ppm Nitrates.. yet my fish keep dying or have cloudy eyes with severe HITH , help me?:

To the OP sorry for the derail and to those whose results Ive questioned , please start another thread so we can fully understand your management techniques..Im on this forum to exchange ideas and learn

 

[HarleyK]

Could you link me to those studies, please? I'd be interested. Thx



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Can't find them, huh?


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[duanes]

http://onlinelibrary.wiley.com/doi/10.1111/are.12098/abstract

 

[HarleyK]

http://onlinelibrary.wiley.com/doi/10.1111/are.12098/abstract

Did you read more than the title?

>exposed to 0.4 (Control), 1.5, 4.2, 9.7 and 27.0 mM nitrate
>Feed intake and specific growth rate were significantly reduced at the highest nitrate concentration.

--> The highest conc is 27 mM nitrate, that's a whopping 1674 mg/L nitrate!!!

>We advise not to exceed a water nitrate concentration of 10 mM (140 mg L&#8722;1 NO3-N) to prevent the risk of reduced growth and feed intake

--> That's 620 mg/L nitrates - I really don't think that anyone on this board would ever dispute such a recommendation


Bottom line: Really?
You said something about studies on 20 ppm nitrate?
ppm and molarity are not interchangeable... didn't you say you were a chemist??

Sorry to sound somewhat disappointed, but when you cited studies, you got me excited - or is there more to the study?

 

[duanes]

This gets a bit more specific as far as breaking down different species tolerance.
http://www.waterboards.ca.gov/water_issues/programs/tmdl/records/region_2/2008/ref2426.pdf
and this was the study about nitrate causing stress in carp, its a bit exhausting because of its length.
Because I concentrate on breeding, the bits about certain levels influence on deformities was of most relevance to me.
http://books.google.com/books?id=B3...uaculture&source=bl&ots=aEZoOhvc5K&sig=fd1CJJ

 

[HarleyK]

Sorry, the stress studies you cite were done on 0.4 and 0.5 g/L, that's 400 and 500 mg/L, I'm still not sure how that translates to the 20 ppm you were talking about ?! I can't seem to be able to access the full thesis - what were the concentrations where deformations were observed? What species? Duration of exposure?

The Chemosphere paper is cool. Thanks for the link!
What it basically tells us is that there are species-differences in nitrate sensitivity. Reviewing the species listed, it makes perfect sense: Trout and salmon reproductive endpoints are the most sensitive. Typically, they occur in coldwater creeks not too far from the spring of a stream, i.e. in low-pollution bodies of water. Salmonidae are about the only fish species that show any sort of sensitivity - remember, table 3 in the Chemosphere paper is mg N/L from nitrate, not mg nitrate/L.

All other species show effects at a couple hundred mg N/L, i.e. around or above 1000 mg nitrate/L. Please note that the 90 mg N/L (=398 mg nitrate/L) for channel cats was a NOAEL (no observable adverse effect level). As said above, no one here will dispute that 1000 is too high.

Sorry, I'm still not seeing how that supports your crusade for <20 ppm nitrates ... unless you keep and breed trout ... or I missed something in the thesis or paper that you might have caught?!

 

[Drstrangelove]

Lets say for sake of discussion an aquarium produces 10 PPM of nitrates a week. ( a week being defined as 5 days) &#8230;lets refer to PPM as units

scenario:

once a week (every 5 days) water change of 50 % assuming no nitrates in tap water.After water change you have a tank with 5 units of nitrates. ( 50% of the original 10 units)

Next week when you go to change water again in 5 days you have 15 units ( 5 remaining and 10 new) of nitrates in the aquarium . change 50 % of water &#8230; after water change you then have 7.5 units

You can see the longer a tank is set up, the harder it is to maintain low nitrates levels through water changes of less than 100 % , alone.

When your taking care of 1000 gallons of aquarium at 50% per week thats 500 gals a week.

And in this example you will be in equilibrium when you start at 10 ppm (right after a WC), grow to 20 ppm in 5 days, then do a 50% WC. Your average nitrates will be 15 ppm which is not altogether bad. You will never get above 20 and you will never fall below 10. But understand that the reason that this example averages 15 ppm is because:

1) the owner is adding 2 ppm nitrates per day
2) the owner is not removing any nitrates daily with plants, purigen or denitrification
3) the owner is only doing a 50% WC

All of the above is under control by the owner. He/she chooses to do these 3 things and not to do other things. It's not fate...it's a choice.

My next question is how much pothos would it take to reduce aquarium water nitrates by 2 units per week? how would you even measure that ?even by subtracting 2 units every week , your nitrate levels at 50% W/C are climbing.

From the research I did (as mentioned) I conservatively calculate that one pothos plant (as described) could remove 6 grams of ammonia/nitrites each 7 days. (4.3 grams each 5 days.) To get an increase of 10 ppm (nitrates) in 5 days in 1,000 gallons of water (as you described), you need to add 37 grams of nitrates in 5 days. To offset 100% of the nitrates, you will need ~9 plants.

Of course, that is not an over stocked tank. That is probably around 25-28 lbs of fish (maybe 4 30" Arowana or 1 3' niger).

Then add to the fact your tap water has nitrate levels ..? it just doesn&#8217;t make sense to me to worry about levels <100 ppm.

My definition of a &#8220;closed loop system&#8221; is an aquarium with out an auto drip exchanger&#8230;.

After years of being on these forums and taking care/breeding rare fish . I am skeptical of these pristine water quality results. You know the posts Im referring too , "my water is perfect 0ppm AMM, 0ppm Nitrites and 0ppm Nitrates.. yet my fish keep dying or have cloudy eyes with severe HITH , help me?:

To the OP sorry for the derail and to those whose results Ive questioned , please start another thread so we can fully understand your management techniques..Im on this forum to exchange ideas and learn

I have no response to this part. People who are more than credible have posted water parameters that are that low or lower.

 

[Drstrangelove]

I'm not a chemist, so I won't try to interpret these results. Perhaps these studies can tell us if 100 ppm nitrates is no big deal.

http://ecan.govt.nz/publications/Re...ity-freshwater-aquatic-species-000609-web.pdf

http://aquaticpath.phhp.ufl.edu/waterbiology/handouts/TheaEdwards2006-EHP.pdf

http://www.es.govt.nz/media/34699/u...ity_effects_on_freshwater_aquatic_species.pdf

http://www.atlantech.ca/public/articles/Water Quality.PDF

I'll post one quote however incorrect it may be, because I think it can help:

"Bonn (1976) reported that adult striped bass tolerated nitrate levels up to 800 mg/L, while fry showed signs of stress at 200 mg/L, however, both adult and fry fed and grew better at levels below 38 mg/L."

The fact that it may take high levels of nitrate to kill fish, should not be confounded with the apparent fact that eggs and fry can die at much lower levels, and that fish at stages may have growth adversely affected at far lower levels of nitrate.