Nitrate In Water

[andywg]

If I were to use distilled water only in the tank will that be removing anything else that the nano need, any minerals etc?

There are two types of water for use in SW: top up water and water change water.

Top Up Water

When the water evaporates from the tank it is just that, water. There is no appreciable decline in the amount of minerals and nutrients in the water. This is why topping up a quickly evaporating tank is not a water change, and why we top up our SW tanks with just water. idelly we want as pure water as we can get, or else we will be constantly adding more and more of the compounds found in water to the tank.

For evidence of this try measuring your salinity (or SG) when the tank is full and then let the water level drop down an inch or so. Then check the water level again. You should notice it has crept up as the water level has dropped (unless the tank is very small in which case it is going to increase at a higher rate).

Water Change Water

When one performs a water change one firt removes some of the water in the tank. This water does have salt dissolved in it, so we therefore have to add new water with the same amount of salt back to the tank to maintain the same salinity.

Marine salt is especially formulated to have all the nutrients a SW tank will need (it is a little low on some of the nutrients necessary for high end stony coral tanks with huge lighting, but it is better to allow them to dose up rather than the everyone else being stuck with unnecessarily high levels). If one mixes this with tap water then one will add the extra nutrients from tap water (often phosphates, silicates and nitrates). To avoid this one can use purer water such as RO/DI or distilled. This gives greater control over what is in the water of the tank.


So to sum up, the use of purer water will not remove nutrients that a tank will need, but it will prevent unwanted nutrients from being introduced.

I should add that the use of purer water (while considered one of the more necessary things in a reef setting, just ask Lynden who tried without it for a while) it is not so necessary in a FO or FOWLR setting as the nutrients added are a problem when combined with sessile invertebrates and/or high lighting, bothe of which are usually absent from a FOWLR/FO.

 

[Musho3210]

my point was an example, hence me saying similar, rather than... well you tell me since you have jumped to that conclusion. Seeing that you can reply so well to many of the topics here, i thought you would have been smart enough to know that. Would it be better if i didnt add examples?

My confusion was that I was asking whether any sfot corals actually want nitrates in the water and will actually use them. You then started to talk about measuring for phosphates in a tank with GHA. I don't see how the two are linked. You have given no example to back up your original inference that there are corals that want nitrate levels.

Do you have a source for any information suggesting that there are soft corals which prefer a level of nitrates around 5ppm (or even at a level detectable by us)? Skifletch's point is a good one, but are those corals flourishing because of nitrates, or in spite of nitrates? I feel it is most likely the latter.

I recall someone recently posting that almost all corals want some nitrates as a nitrogenous compound will be required by zoothanellae. They did not, however, address my point that the idea of a symbiotic relationship is that each gets benefit from the other, and any nitrogenous demands from the algae will probably be satisfied by that produced by the coral it is with.

Andy, you are just repeating what you said earlier, which i only need to reply with, its an example. I think from now on i shouldnt give you examples as it will make you think much better (which is very very strange). If i didnt add the GHA part, my point would have still been made. So i appologize for the example, obviously you learn better without them. May i add my confusing part? You say your confusion was in the nitrates in water helping corals, but then you say i dont see how the two are linked. They arent link directly (oh my god), when someone says they have a lot of GHA, they have a large bio-load, small bi-weekly water changes, phosphate rich source water, and food high in phosphates, some say test phosphate, they say they are none. What is the reason for that? Someone says they over feed, have a small amount of live rock, no deep sand bed, no skimmer, lots of soft corals, large bio-load, small bi-weekly water changes. Someone asks for nitrate levels, there are none. What is the reason for that. Please andy, dont be this stupid.... i really thought you would be smart enough to think of things as examples rather than directly linked items that are both part of a charm necklace. I find some deep hypocrisy in your last post....

Scientific proof? Not that i can find of, evident assumptions, yes, i know some people near me with full soft coral tanks who dose nitrate, great coral, huge amount of growth (lots of fragging). You are going to say that it would be exactly the same without the dosing right? Well now its your turn, do you have scientific data that debunks this myth? If you dont then we cannot decide which one of us is correct because evidential assumptions/your word isnt good enough.

 

[andywg]

Now now, no need to get so upset because your drifting example wasn't caught by me. That's why I asked for clarification. That's the way to a constructive debate, rather than name calling.

Scientific proof? Not that i can find of, evident assumptions, yes, i know some people near me with full soft coral tanks who dose nitrate, great coral, huge amount of growth (lots of fragging). You are going to say that it would be exactly the same without the dosing right? Well now its your turn, do you have scientific data that debunks this myth? If you dont then we cannot decide which one of us is correct because evidential assumptions/your word isnt good enough.

I don't think that I asked for scientific evidence, just a source on which you made the statements. These observations your friend has made are not evidential assumptions, they are anecdotal evidence. Is the test done against a control? No. Can they be sure it is the coral using the nitrate? No. Have they performed this in a number of different scenarios? No.

I say again, how can you be sure the corals are growing well beause of the nitrates, rather than in spite of the nitrates? It is well known that nitrates are poisonous to corals at low levels (including many soft corals by 5ppm), so I will opt for the latter until I hear differently.

 

[Musho3210]

I dont know where you got that i was upset? Care to elaborate MY feelings? Where did you find the corals are sensitive to nitrates even at 5 ppm? You asked for evidence, i couldnt give you any strong evidence, i ask for evidence, i get a re-question which ive already answered, and i shall answer again..... Yes i have no proof proof, no i do not think low nitrates are at all toxic to corals, since ive been perfectly fine with them in my tank since day 1.

And i might add, i never called you a name, i used an adjective. So i dont know where you got the name calling from.

I think im gonna say that a 5 ppm nitrates is fine until i have evidence that it is not. You say its well known that it is, so it shouldnt be hard for you to find a reliable source will it?

 

[Apistogramma]

Thanks Musho, Andy and everyone else who has contributed. It's obvious that Musho and Andy both have plenty of knowledge but perhaps chose to share it in slightly different ways. Reading all of it together gives me a wider understanding than I would have otherwise so please agree to differ but don't fall out over it.
Only a very tiny amount of water evaporates from my tank as it has a hood but I am going to try and find a local source of distilled water and start using it in the tank. This is my 'experimental tank' - I'm not trying to achieve a stunning looking fo or fowlr, I have live rock and the idea was to try and keep some soft corals in a small tank with the minimum of equipment and expense as my first experience of salt tanks.
Thanks muchly for the help.

 

[andywg]

I dont know where you got that i was upset? Care to elaborate MY feelings?

If you were posting with an entirely clear head without any high riding emotions you would not have posted comments such as "please don't be so stupid" when I had already pointed out I was confused by your statement.

Where did you find the corals are sensitive to nitrates even at 5 ppm? You asked for evidence, i couldnt give you any strong evidence, i ask for evidence, i get a re-question which ive already answered, and i shall answer again..... Yes i have no proof proof, no i do not think low nitrates are at all toxic to corals, since ive been perfectly fine with them in my tank since day 1.

From Randy Farley-Holmes:

Nitrate is an ion that has long dogged aquarists. The nitrogen that forms it comes in with foods, and can, in many aquaria, raise nitrate enough to make it difficult to maintain natural levels. A decade or two ago, many aquarists performed water changes with nitrate reduction as one of their primary goals. Fortunately, we now have a large array of ways to keep nitrate in check, and modern aquaria suffer far less from elevated nitrate than did those in the past.

Nitrate is often associated with algae, and indeed the growth of algae is often spurred by excess nutrients, including nitrate. Other potential aquarium pests, such as dinoflagellates, are also spurred by excess nitrate and other nutrients. Nitrate itself is not particularly toxic at the levels usually found in aquaria, at least as is so far known in the scientific literature. Nevertheless, elevated nitrate levels can excessively spur the growth of zooxanthellae, which in turn can actually decrease the growth rate of their host coral.

For these reasons, most reef aquarists strive to keep nitrate levels down. A good target is less than 0.2 ppm nitrate. Reef aquaria can function acceptably at much higher nitrate levels (say, 20 ppm), but run greater risks of the problems described above.

In particular it poses problems for calcifying corals, such as Porites compressa where levels of as little as 0.3 to 0.6ppm reduced the growth rate (Effects of lowered pH and elevated nitrate on coral calcification. Marubini, F.; Atkinson, M. J. Marine Ecology: Progress Series (1999), 188 117-121.[/i]

I think im gonna say that a 5 ppm nitrates is fine until i have evidence that it is not. You say its well known that it is, so it shouldnt be hard for you to find a reliable source will it?

I said that by 5ppm nitrate starts to become posionous to a number of corals. This is somewhat incorrect as it actually slows the growth of the corals (potentially leading to death) but the problems are not primary results of the nitrates, but due to other events which do depend on the nitrates being present. Also, it woudl seem that the levels can be higher.

However, this is a digression. Let's look at your first post:

...the pink coral could be a soft coral that actually wants the nitrate in the water.

That statement implies you are aware of corals that perform better with nitrates in the water. I asked how you knew they prefer nitrates but you have only been able to say that you know someone who has corals that are growing well in a tank with 5ppm but admit you have no idea whether it is the nitrates causing that or something else and that the nitrates are immaterial.

The above has shown that nitrates can be higher than what many of us hope for, but it by no means supports the notion that any coral needs an inflated nitrate level.

 

[Musho3210]

I dont know where you got that i was upset? Care to elaborate MY feelings?

If you were posting with an entirely clear head without any high riding emotions you would not have posted comments such as "please don't be so stupid" when I had already pointed out I was confused by your statement.

Where did you find the corals are sensitive to nitrates even at 5 ppm? You asked for evidence, i couldnt give you any strong evidence, i ask for evidence, i get a re-question which ive already answered, and i shall answer again..... Yes i have no proof proof, no i do not think low nitrates are at all toxic to corals, since ive been perfectly fine with them in my tank since day 1.

From Randy Farley-Holmes:

Nitrate is an ion that has long dogged aquarists. The nitrogen that forms it comes in with foods, and can, in many aquaria, raise nitrate enough to make it difficult to maintain natural levels. A decade or two ago, many aquarists performed water changes with nitrate reduction as one of their primary goals. Fortunately, we now have a large array of ways to keep nitrate in check, and modern aquaria suffer far less from elevated nitrate than did those in the past.

Nitrate is often associated with algae, and indeed the growth of algae is often spurred by excess nutrients, including nitrate. Other potential aquarium pests, such as dinoflagellates, are also spurred by excess nitrate and other nutrients. Nitrate itself is not particularly toxic at the levels usually found in aquaria, at least as is so far known in the scientific literature. Nevertheless, elevated nitrate levels can excessively spur the growth of zooxanthellae, which in turn can actually decrease the growth rate of their host coral.

For these reasons, most reef aquarists strive to keep nitrate levels down. A good target is less than 0.2 ppm nitrate. Reef aquaria can function acceptably at much higher nitrate levels (say, 20 ppm), but run greater risks of the problems described above.

In particular it poses problems for calcifying corals, such as Porites compressa where levels of as little as 0.3 to 0.6ppm reduced the growth rate (Effects of lowered pH and elevated nitrate on coral calcification. Marubini, F.; Atkinson, M. J. Marine Ecology: Progress Series (1999), 188 117-121.[/i]

I think im gonna say that a 5 ppm nitrates is fine until i have evidence that it is not. You say its well known that it is, so it shouldnt be hard for you to find a reliable source will it?

I said that by 5ppm nitrate starts to become posionous to a number of corals. This is somewhat incorrect as it actually slows the growth of the corals (potentially leading to death) but the problems are not primary results of the nitrates, but due to other events which do depend on the nitrates being present. Also, it woudl seem that the levels can be higher.

However, this is a digression. Let's look at your first post:

...the pink coral could be a soft coral that actually wants the nitrate in the water.

That statement implies you are aware of corals that perform better with nitrates in the water. I asked how you knew they prefer nitrates but you have only been able to say that you know someone who has corals that are growing well in a tank with 5ppm but admit you have no idea whether it is the nitrates causing that or something else and that the nitrates are immaterial.

The above has shown that nitrates can be higher than what many of us hope for, but it by no means supports the notion that any coral needs an inflated nitrate level.

Ok, i was wrong, i can admit that, i said please dont be stupid because i thought you were smarter than that, not because i wanted to actually call you stupid. I dont think you are the proper candidate to decide my "tone," "attitude," "clear-headednece" and "body language". I dont see how this makes me emotional....

Anyway, the evidence you posted didnt say that corals dont use the nitrate.... Yes i was wrong about it having no bad effects, but the evidence did not say corals dont absorb and use nitrates. The evidence also didnt specify actual ppm or ppb levels. So unfortunately, i am still unchanged in this matter.

Finally, in my statement, i said could, that does not mean it does, and it does not mean that it doesnt. It was a guess that goes with my hypothesis. If i had said the pink coral is a soft coral that actually wants the nitrate in the water, then yes, your last paragraph is correct.

 

[Lynden]

Pick your battles Musho. Believe me, Andy is NOT someone you want to argue with... I'll bet he can tell you how frustrated I got with 'im at times. But, that was years ago and I've realized just how wrong I was (and how poorly I was arguing).

Bottom line, corals can tolerate some nitrate. Their symbionts do need a little of it but this is provided by the coral animal itself (as poop). The more nitrate they have to tolerate the slower they will grow.

Phosphate is a slightly different matter.

"The effect of phosphate levels on filter feeders and organisms that feed primarily by absorption is complex and poorly understood. For example, the aquaculture of certain organisms, such as Xenia species, may benefit from phosphate levels above normal sea water values, whereas stony corals may benefit from levels below natural sea water values."

-Charles Matthews, Marine and Reef USA 2006 annual, page 52

 

[Musho3210]

Pick your battles Musho. Believe me, Andy is NOT someone you want to argue with... I'll bet he can tell you how frustrated I got with 'im at times. But, that was years ago and I've realized just how wrong I was (and how poorly I was arguing).

Bottom line, corals can tolerate some nitrate. Their symbionts do need a little of it but this is provided by the coral animal itself (as poop). The more nitrate they have to tolerate the slower they will grow.

Phosphate is a slightly different matter.

"The effect of phosphate levels on filter feeders and organisms that feed primarily by absorption is complex and poorly understood. For example, the aquaculture of certain organisms, such as Xenia species, may benefit from phosphate levels above normal sea water values, whereas stony corals may benefit from levels below natural sea water values."

-Charles Matthews, Marine and Reef USA 2006 annual, page 52

well that was strange... im sorry if you view this as a battle....

 

[Apistogramma]

Pick your battles Musho. Believe me, Andy is NOT someone you want to argue with... I'll bet he can tell you how frustrated I got with 'im at times. But, that was years ago and I've realized just how wrong I was (and how poorly I was arguing).

Bottom line, corals can tolerate some nitrate. Their symbionts do need a little of it but this is provided by the coral animal itself (as poop). The more nitrate they have to tolerate the slower they will grow.

Phosphate is a slightly different matter.

"The effect of phosphate levels on filter feeders and organisms that feed primarily by absorption is complex and poorly understood. For example, the aquaculture of certain organisms, such as Xenia species, may benefit from phosphate levels above normal sea water values, whereas stony corals may benefit from levels below natural sea water values."

-Charles Matthews, Marine and Reef USA 2006 annual, page 52

well that was strange... im sorry if you view this as a battle....

You're giving my pink coral a complex...
I wasn't going to start trying to increase nitrate levels based on Musho's comments - don't panic!
Thank you both for your help...*flees the forum*

 

[andywg]

Anyway, the evidence you posted didnt say that corals dont use the nitrate....

But that was not my point. You statement seems to claim that some corals prefer nitrates. I am unsure of this because other sources (such as that posted by me) indicate that nitrates become a problem for corals. It is you who made the statement that some corals (may) want nitrates. It is not my place to disprove that, but your place to provide evidence that supports your statement.

You have admitted that you only have mild anecdotal evidence of this so I think we can rest with you stating you believe some corals benefit from it, and me stating that there is no evidence to support this, but there is evidence to show that increased nitrate levels are a prbolem both for corals and the tank they are in and that any such level is grossly more than that in the natural waters which the corals come from.

Yes i was wrong about it having no bad effects, but the evidence did not say corals dont absorb and use nitrates. The evidence also didnt specify actual ppm or ppb levels. So unfortunately, i am still unchanged in this matter.

Well, Joe Jaworski's blog notes:

Nitrate levels in aquariums are much higher than those in the ocean. The average nitrate levels of the ocean is 0.1 ppm at depths up to 50 meters, and 2.5 ppm and higher in deeper regions. But in the South Pacific reefs where we get most of the creatures we want to keep, nitrate levels average around 25 ppb (that’s parts per billion) which is equivalent to 0.025 ppm. So here’s the first problem: a typical hobby nitrate test kit can only go down to about 1.0 ppm, which is a nitrate level 40 times higher than what we’re shooting for. If you test for nitrates and the test vial looks crystal clear and colorless, your nitrate level could still be a hundred times higher than the ocean levels.

Mr Jaworski does not cite his references, but is the President of Asheville Marine Aquarium Society, so one would hope he has some backing for his claims.

Furthermore, in Nitrogen uptake in the scleratinian coral Stylophora pistillata, Renaud Grover, Jean-Francois Maguer, Denis Allemand, Christine Ferrier-Pages Limnology and Oceanography, Vol. 48, No. 6 (Nov., 2003), pp. 2266-2274 it is noted that:

Reef waters usually contain low levels of inorganic nutrients. The ranges of nitrogen concentrations are typically of 0.3 to 1 micromol/L nitrate and 0 to 0.4 micromol per litre ammonium (Bythell 1990, D'Elia and Wiebe 1990, Furnas 1991).

My understanding here is far from perfect, but here goes:

Assuming the nitrate is present as NO3 then one mole will be 62g (one nitrogen atom at 14, 3 oxygen atoms at 16). One micromole will be 0.000062g, or 0.062. 0.062mg/l is roughly the same as 0.062ppm, or 62ppb. This is the higher level measured by scientists, with the levels ranging as low as 18.6ppb.


So in conclusion, I think we have found that nitrates are extremely low on the natural reef, elevated nitrates can cause problems with the coral itself, and with the tank (through algal growth and such). Your friend has a tank which has very good growth on a soft coral despite the nitrate levels being somewhat higher than the natural environment, but it cannot be said whether the nitrates are truly conributing to this growth. You have your belief on this, I have mine.

 

[Musho3210]

i understand natural reef levels, i have my own source that also states that NSW has that low amount of nitrate. But yet again, your source fails to put two ends meet, the second source doesnt state that this elevated nitrate levels in the tank poses any harm. It can be assumed, but like you said, assuming isnt good enough evidence.

 

[Lynden]

well that was strange... im sorry if you view this as a battle....

How was it "strange"? I added my thoughts and they were completely relevant to the discussion. By the way "pick your battles" is a figure of speech.

I think you may be getting phosphate confused with nitrates. Phosphates do in fact help soft corals according to my source (you would have known that had you acknowledged my previous input); nitrates do not. They grow in spite of the extra nitrate, not because of it, although they can tolerate fairly high amount. The coral animal provides plenty of nitrate for the symbiosis to function.

From Bob Fenner (of wetwebmedia):

Any amount of investigation into "dreaded nitrates" in hobby literature, the Net, conversations with others... will reveal an enormous amount of differing opinions on the importance/significance of their presence/concentration. Are nitrates important as sources of poisoning of marine livestock? By and large for most species of life, no. Can nitrate measure be useful as an overall indicator of system health, trends in water quality changes, wake-up calls for altering, enhancing methods of overall system improvement? Sure.

Without implementing some of the above methods of control, nitrates will/do accumulate in marine aquariums. Your role as the "creator", and on-going manager of said systems is to devise and impose balance between inputs of nitrate sources and the practical continuous elimination of their accrual.

Ideally you want your nitrates to be as low as possible. For invertebrate-containing marine systems, a few ppm (up to five as a rule of thumb) is likely acceptable, and a few tens of ppm for fish-only systems. Just having "some" nitrate concentration present in the grand scheme of things that contribute to livestock health is not a real menace.

P.S.
Calling someone "stupid" does not make up for your lack of understandability and relevance.

 

[steelhealr]

I think apistogramma's question was answered earlier in the post. Distilled water is fine to either top off with or mix with salt mix to make sea water. It should be 0 TDS. I've checked my distilled from our grocery and it was at 0.

As for nitrates, the above post by Farley-Holmes is a good one. There ARE some corals that prefer to exist in lagoons with runoff from the beach. You can all look up You can all look up fox coral, nemanzophyllia sp. . Our tanks are more tolerant of nitrates than we think, but, in general, I believe most of us would go with the 'standard of care' and panic a bit of we started climbing over 20ppm.

SH