Acceptable Nitrates

[Reef_Tank_Fan_SC]

Hello reef fam,

I’m just curious what the experts think nitrate levels need to run at. I’ve done a bunch of research and honestly opinions are all over the place. I know that stability is key but there has to be a point at which we start noting problems. Some corals like nitrates in the tank but at what point do we cross the line to being harmful. I’d like to get some general top and bottom levels so that I can know when I’m entering the danger zone so to speak. I want to have a good water change regiment but I don’t want it so clean that my LPS struggle. Thanks for all tips and advice and for anyone who cast a vote thanks for helping out also

 

[14 foot reef]

Balance your NO3 & PO4 100 to 1 ratio. If you're doing mixed reef try not to exceed 25ppm NO3 so that's NO3 - 25 -- PO4 .25
I run 18 NO3 and PO4 .17 850 gallon mixed reef leaning heavy on SPS

 

[Randy Holmes-Farley Verified Community Expert]

Acceptable is a different question than optimal.

100 ppm can be acceptable to have a great tank, but, IMO, 2-10 ppm is better.

 

[Randy Holmes-Farley Verified Community Expert]

Balance your NO3 & PO4 100 to 1 ratio. If you're doing mixed reef try not to exceed 25ppm NO3 so that's NO3 - 25 -- PO4 .25
I run 18 NO3 and PO4 .17 850 gallon mixed reef leaning heavy on SPS

What is your basis for thinking that ratio is best?

 

[Reef_Tank_Fan_SC]

Acceptable is a different question than optimal.

100 ppm can be acceptable to have a great tank, but, IMO, 2-10 ppm is better.

This is exactly what I was trying to say. It’s very hard for a new reefer or someone that been out for a while and return to find accurate information. However I think that’s because everyone’s tank is different. So instead of a particular number it might be more balance or what said tank likes. But again at some point there is a cutoff point and I think it would be less than the 100ppm… lol. I’m just hoping to get a general high-low idea for a good starting point for incoming reefers with a new tanks that want to see a general good/bad guideline

 

[Bucs20fan]

So, Ive had ups and downs as most of us have had in reefing as far as nutrients. As long as you are not sps dominant, most softie and LPS will thrive in "Dirty water" aka higher nitrates and phosphates. The downside to this is algae will grow. I have several high end torch corals, and at one time had nitrates that maxed out a hanna high range checker and an API nitrate test. This was due to a dead urchin that was decaying. And none of the softies or lps were any worse for wear.

This is not to say to keep super high nitrates, but I personally try to keep mine about 30 and phosphate below .5 and I have a random millieopora, an oregon tort, several montis and an pc rainbow that are doing great with those levels.

 

[Randy Holmes-Farley Verified Community Expert]

I’m just hoping to get a general high-low idea for a good starting point for incoming reefers with a new tanks that want to see a general good/bad guideline

My general recommendation is 2-10 ppm nitrate and 0.02 to 0.1 ppm phosphate, with values above the ranges better than values below it.

I discuss all my recommendations and give reasons for them here:

Optimal Parameters for a Coral Reef Aquarium: By Randy Holmes-Farley

[note: edited on 5/29/2022 to update the nitrate and phosphate sections with higher recommended levels.] One of the main roles of an aquarist with a coral reef aquarium is to ensure that the conditions are right for their tank inhabitants. There are many different attributes of the aquarium...

www.reef2reef.com

 

[piranhaman00]

<50ppm

 

[ReefGeezer]

There is no exact right answer to the question. I choose 5-10 ppm as a good target, but higher can be fine also, depending on the individual tank. I think any number above 0 indicates that there is adequate nitrogen in the system for all the organisms to use. Zero is not good though, so 5-10 allows for a buffer. The acceptable range in any particular tank depends somewhat on its level of maturity. Older, more mature tanks can thrive with higher levels on nitrate because other conditions (bare substrate, lack of algae grazing organisms, and etc.) that might let pest algae bloom are not available.

 

[14 foot reef]

What is your basis for thinking that ratio is best?

@Randy Holmes-Farley This is just a window of advise that seems to work for a lot of people and I see your recommendation falls in that close range. I don't think this is an absolute, but I think it's not a bad target for a beginner to an intermediate reefer. I would never challenge your scientific knowledge at all. I just thought this was a good starting point to guide his path to a successful end.

 

[Rjmul]

Spin a wheel, throw a dart

 

[Sean Clark]

I'll go on record and state that nitrates are not the reason you are having issues.

 

[bushdoc]

I presume that most reefers ( but obviously not all) would agree that 0 Nitrates or values close to 0 are not acceptable. Problem arises when we discuss what is the highest acceptable value. High Nitrates are rarely just high nitrates, usually phosphates are also elevated and all this is due to addition of too many nutrients to the tank and subsequent eutrophication, therefore usually is a results of poor aquarium maintenance. Acceptable values can also be different for different type of Reef tank, for soft coral especially Nitrates can be higher, for SPS, lower. I try to keep my Nitrates < 10 ppm, unfortunately they hit recently levels < 1 ppm albeit no obvious deleterious effect seen yet.

 

[Reef_Tank_Fan_SC]

I'll go on record and state that nitrates are not the reason you are having issues.

I’m not having any issues (currently). This was just a topic that I’ve come across and no matter what I read or who I discussed it with there was always a difference of opinion. Like I stated before I’m sure it’s probably tank dependent, the closest thing I see to an agreeable answer is the 100: ratio mentioned earlier

 

[Sean Clark]

I’m not having any issues (currently). This was just a topic that I’ve come across and no matter what I read or who I discussed it with there was always a difference of opinion. Like I stated before I’m sure it’s probably tank dependent, the closest thing I see to an agreeable answer is the 100: ratio mentioned earlier

I was guilty of posting to the latest post and then reading up. I think your logic is sound

 

[Reef_Tank_Fan_SC]

I was guilty of posting to the latest post and then reading up. I think your logic is sound

Well I appreciate the post activity, because I’m sure at some point I will need help with something. Lol

 

[Randy Holmes-Farley Verified Community Expert]

I’m not having any issues (currently). This was just a topic that I’ve come across and no matter what I read or who I discussed it with there was always a difference of opinion. Like I stated before I’m sure it’s probably tank dependent, the closest thing I see to an agreeable answer is the 100: ratio mentioned earlier

I'd be VERY cautious in thinking of nutrients in ratios.

No one has ever shown (IMO) why it is a better way to consider N and P than than to discuss the absolute values, and it can be much worse.

One could obviously have that same ratio (any ratio) at levels of both that are far too low, or far too high, but are the perfect ratio.

But one cannot ever have a problem with a "wrong ratio" if you only consider the actual values as the target.

So why bother using ratios at all?

 

[Bucs20fan]

Get you some decent nitrates, 20 or so, a little phosphate, .1-.5 and grow yourself some corals!

 

[Reef_Tank_Fan_SC]

I'd be VERY cautious in thinking of nutrients in ratios.

No one has ever shown (IMO) why it is a better way to consider N and P than than to discuss the absolute values, and it can be much worse.

One could obviously have that same ratio (any ratio) at levels of both that are far too low, or far too high, but are the perfect ratio.

But one cannot ever have a problem with a "wrong ratio" if you only consider the actual values as the target.

So why bother using ratios at all?

I agree with you. That’s what I was saying about how that ratio being the only thing that was thrown out between numerous different people and forums. It was one of the main reasons I posted this thread, lol. I 100% agree that using it will get you in a ballpark and that people using it have successful reefs. However a numerical stopping point or “warning point” would seem more useful for people that want to stay within a certain range. Like you have laid out in you post where you put the recommendation based on your research. That’s the kind of info that I want to help newer people get to, especially when they get overwhelmed with seeing so many different opinions