nitrate level?

SecretiveFish

New member
Depends what type of creatures you want to keep.

IME, corals like polyps, mushrooms, leathers, clams, and large polpy stonies do OK with <20 nitrates. This is not true for ALL of these, but has been true for the ones I have bought.

Fish can generally tolerate 20-40ppm fine

Some corals like acros need nearly perfect water chemistry with nitrates <5ppm!! I have never tried acros because I can't get my water quality that high! Also types sponges that can be purchased fall into this category.

A note: when my nitrate test kit went bad and I didn't know it, I had multiple fish, leathers. mushrooms and polyps doing just fine for >6 months at 80ppm. Please note this was not intentional but was a newbe mistake. Also, I did not have any SPS type corals which I do not think would have tolerated this at all.
 

Chris27

New member
Corals are more sensitive to it then anything else really, for those it's good to be less then 20ppm. When it comes to just fish, the sky is the limit, anything under 100ppm is fine for them, and oftentimes you can go higher without any ill effects.
 

MrTuskfish

Team RC
ALL OF THE FOLLOWING REFERS TO FISH ONLY TANKS, NOT REEFS.

Most fish have no problem with nitrate well above, say, 40ppm. Inverts are another story. Actually, fish can do just fine with nitrates many times what I'm willing to post. But, I think the poor housekeeping that is suggested by sky-high nitrates can lead to other problems. Fenner's original edition of 'The Conscience marine Aquarist" mentions fish being kept at "hundreds, even thousands of ppm" without problems. he does add "of course, the lower, the better." My FOWLR tanks are higher in nitrate than I want to admit. just for fun, grab a sample of your LFS water (from fish-only tanks) and test it. I'll bet its over 100ppm. This isn't an endorsement for high nitrate in fish-only systems; just info for hobbyists going nuts and spending a fortune trying to get fish-only systems to a tiny nitrate reading.
 

m.gumbert

New member
In my book it is "0" or undetectable. My tank has never been over 10 ppm. If I see the nitrate level climbing I immediatley turn the RO/DI on and beging making a batch of water for a change. It also helps to have a fuge and correctly sized protien skimmer. Nitrates are deadly to fish at high quanities. It burns the thier gills and body, Imagine if you dipped your hand into hydrochloric acid. Thats probably what the fish feels like swiming around in high nitrate levels.

This is a excerpt from a Reef Keeping Magazine Article titled Aim for the Optimal, Not the Minimal written by: Nate Enders

"A sobering fact is that even the best aquariums most likely falls short of recreating a natural reef environment in many basic ways – light intensity, flow, availability of food, biodiversity and so on. Sadly, despite these obvious shortcomings in our practices, hobbyists are often only interested in the minimum requirements for keeping certain livestock. This is evident through many common questions on the forums: “Can I get by keeping a clam under PCs?” “Will a tang survive at least a few years in my 55?” In a way, this is only natural - hobbyists so interested in a particular specimen are hopeful that their tank can at least meet the minimum requirements to keep it alive. However, in most cases, these minimal requirements will fall far short of recreating that specimen’s natural habitat. These two thoughts leave us with a moral dilemma: If it’s just not possible to fully recreate nature, to what extent should we try? Successful reefkeepers know that the minimum is not acceptable. There is a difference between livestock that survives, and livestock that thrives. Even if we cannot fully mimic a reef in our home aquariums, making the best attempt possible will give our livestock the best chance of thriving, and will give us hobbyists a more enriching experience. At the very least, exceeding the minimum gives us a cushion in case of emergency, or in case the expert dictating that minimum was wrong!"
 

MrTuskfish

Team RC
In my book it is "0" or undetectable. My tank has never been over 10 ppm. If I see the nitrate level climbing I immediatley turn the RO/DI on and beging making a batch of water for a change. It also helps to have a fuge and correctly sized protien skimmer. Nitrates are deadly to fish at high quanities. It burns the thier gills and body, Imagine if you dipped your hand into hydrochloric acid. Thats probably what the fish feels like swiming around in high nitrate levels.

This is a excerpt from a Reef Keeping Magazine Article titled Aim for the Optimal, Not the Minimal written by: Nate Enders

"A sobering fact is that even the best aquariums most likely falls short of recreating a natural reef environment in many basic ways "“ light intensity, flow, availability of food, biodiversity and so on. Sadly, despite these obvious shortcomings in our practices, hobbyists are often only interested in the minimum requirements for keeping certain livestock. This is evident through many common questions on the forums: "œCan I get by keeping a clam under PCs?" "œWill a tang survive at least a few years in my 55?" In a way, this is only natural - hobbyists so interested in a particular specimen are hopeful that their tank can at least meet the minimum requirements to keep it alive. However, in most cases, these minimal requirements will fall far short of recreating that specimen's natural habitat. These two thoughts leave us with a moral dilemma: If it's just not possible to fully recreate nature, to what extent should we try? Successful reefkeepers know that the minimum is not acceptable. There is a difference between livestock that survives, and livestock that thrives. Even if we cannot fully mimic a reef in our home aquariums, making the best attempt possible will give our livestock the best chance of thriving, and will give us hobbyists a more enriching experience. At the very least, exceeding the minimum gives us a cushion in case of emergency, or in case the expert dictating that minimum was wrong!"

I agree with the broad intent "Aim for the Optimal' article. but do you have a source for the comments about nitrate burning gills? I know ammonia does. I've never heard this before. In fact, I've never seen anything, except anecdotal observations with a few species, that nitrates bother fish at all.
 

EdKruzel

Premium Member
I agree with the broad intent "Aim for the Optimal' article. but do you have a source for the comments about nitrate burning gills? I know ammonia does. I've never heard this before. In fact, I've never seen anything, except anecdotal observations with a few species, that nitrates bother fish at all.

+1 Aim for optimal. Nitrate is non-toxic; however excessive levels show a short coming in your cycle. The complete cycle is to convert ammonia to nitrite, nitrite to nitrate and then nitrate to nitrogen gas. This is easily accomplished with a DSB or denitrification filter or simply skipping that step and manually removing the cause of the nitrate build-up with water changes.

Low bioloads and oversized equipment such as skimmers and mechanical filtration/sumps will help to process and remove waste before it can break down and raise the levels.
 

MrTuskfish

Team RC
+1 Aim for optimal. Nitrate is non-toxic; however excessive levels show a short coming in your cycle. The complete cycle is to convert ammonia to nitrite, nitrite to nitrate and then nitrate to nitrogen gas. This is easily accomplished with a DSB or denitrification filter or simply skipping that step and manually removing the cause of the nitrate build-up with water changes.

Low bioloads and oversized equipment such as skimmers and mechanical filtration/sumps will help to process and remove waste before it can break down and raise the levels.

Well put. I don't know where the line is, but I think way too many owners of fish-only systems believe that nitrate is toxic to fish. I certainly don't want to encourage high levels of nitrate, but hate to see people going crazy over a level that is meant for a reef and not necessary in a FOWLR. Before LR made reefkeeping possible, I can't remember anyone even knowing what nitrate was, much testing for it. I'd hate to encourage lax housekeeping while letting folks know that some nitrate in a fish-only system is no problem. I assume when reefkeeping, and the need for minimal nitrates became known, the myth that nitrates (at any measurable level) were deadly to fish. This just isn't so and many people are really surprised when they discover this. LA suggests nitrates at a max of 30 ppm for fish-only systems. The source for LA info is an outstanding hobbyist and I think this would be a reasonable, attainable goal for fish-only tank owners.
 
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