Can 0ppm nitrate actually affect a reef in a negative way?

[Mindi]

Read the two articles on Master's Tanks in this forum. It is a real eye opener. I actually pulled together all their critical reported parameters and found the average for these sensational tanks. NO3 average was 19.7ppm, and PO4 was 25 ppb as Phosphorus or about 0.10 PO4. No...I have no idea how they manage undesired algal growth, but go to the two articles and see their corals....awesome. I just got over the whole ultra low nutrient thing when I read them

 

[Hans-Werner]

The problem especially with nitrate is the detection limit, 0 is never absolute 0 but maybe 0.something. I had absolutely no coloration of a nitrate test, it stayed totally clear for years without doing any harm to the corals. I am sure nitrate was <1 ppm. In my eyes phosphate is much more important and I would prefer 0.05 to 0.1 ppm phosphate for good coral growth or 0.02 to 0.05 ppm for slow coral growth. With 0.01 ppm of phosphate the growth of SPS corals is really slow. These given values are all reactive phosphate measured with a laboratory photometer. The total phosphate concentrations measured with ICP-OES may be much higher, as high as 0.08 or 0.1 ppm when reactive phosphate is 0.01 ppm. These are at least my results when comparing total phosphate after persulfate digestion with reactive phosphate with a photometer.

It is true that a lack of nitrogen compounds makes the coral appear pale or very lightly colored but usually it makes no tissue necrosis. You will see if you have a nitrogen deficiendy long before you get serious problems with the corals. If the color of the corals is ok you don´t have a nitrogen deficiency no matter what your nitrate test says. Nitrate is just a kind of waste product of the nitrogen circle. If there are more available nitrogen compounds than can be taken up by the corals and algae then you get nitrate.

With phosphate it is just vice versa. With phosphate the corals may be dark in color (and even PE may be good) but they start to show tissue necrosis. You get tissue necrosis of corals and the corals may die if you can´t stop it without any prior warning. This makes phosphate deficiency much more dangerous than nitrogen deficiency.

 

[LV3]

I've experienced what you're describing regarding low nutrients. I ended up dosing to raise the NO3 in one of my tanks. Now, I've increased my livestock load to help maintain 5ppm NO3.

In case you're interested:
https://www.reef2reef.com/threads/0-nitrates-so-i-dosed-sodium-nitrate.302544/

 

[Nano sapiens]

Some very good info here and the various experiences and recommendations show that each system can be quite different in regards to the processing of available nutrients.

I have a small 'unfiltered' reef system that has been in continuous operation for over 9 years. For the first 2 years it ran with higher NO3 (~15-20 ppm) and PO4 (~.08 ppm), but the next 7 years NO3 <1 ppm and PO4 'undetectable' (Salifert) due to a major change in how I maintain the system. One might think that with such apparently low nutrient levels the corals would be pastel colored with slow, or no growth, but the exact opposite is true.

This is an example of a system testing as a 'low nutrient system', but it most certainly is not as it is fed quite generously 2x/day. It's clear that the available nutrients are being efficiently utilized by the resident organisms (macro and micro). A regular weekly maintenance schedule, which includes partial water changes and the removal of a portion of the sequestered organics (detritus with some substrate bacteria) via vigorous vacuuming, keeps the system from becoming eutrophic.

Ralph.

 

[CastAway]

Tagging along....

 

[edosan]

My 2 cents:
Low is one thing, Cero is another. I you keep in cero for 2 long (easy with carbon overdosing), your corals will pale (sps) and then will die. For some reason LPS will look better than ever, but eventually they will fade away too.
I have been in cero, and with high nutrients, after testing a lot for me is:
No3 = arround 1 to 5 ppm (Salifert, basically a slight tint, but very slight)
Po4: = arround 0.03 to 0.08 ppm (Hanna Phosphorus ULN)

But it will depend a lot on the corals you want to keep, and where they come from. Usually when we talk about nutrients, we talk SPS, and acroporas mainly. LPS and Soft usually they adapt much better to a wide range of nutrients.

IME:
Wild SPS (or maricultured) will need NSW conditions usually
Acuaculture SPS (Tank raised), will have much more tolerance to high nutrients, and better coloration too (not always)

 

[brandon429]

Ralph you beat me to it

Zero detectable nitrate and phosphate is bad when we expect corals to grow in our housed system using the typical starving feed modes the masses employ to ward off algae

It's always how little can I provide and still keep color and growth, a minimalist approach
But corals adapted to abundance of feed...can catch floc and pods and other fish and gametes and juvenile pelagic organisms and worms forever, on down the line... In pristine low dissolved nutrient waters (ideally)

Average Joe's system is underfed, nonvariable, and on top of that Joe wants low dissolved nutrients such that they'll never have to touch a rock to guide out algae. Works well when balanced, but tricky balance to attain.

But if we maximize -suspended- whole protein foodstuffs (feed and change water more actively, before breakdown within tank) then everyone's fed wholly and no. -dissolved- nutrient spikes will occur.

We drive nanos and picos to near universal success with this method.



This is one reason it's ironically true that it's easier to grow SPS in smaller containers vs large ones because we can control the water column instantly

It used to be the rumor that added dilution was key to success

No

It's being able to feed and change water before it rots. That and never bumping the system accidentally with an elbow

many of our new keepers at nano-reef.com picos forum are keeping sps as part of the first group of corals. In fact, we don't even measure calcium and alk in any of them, we just feed and change water and take pics

It's cpr in/out process

Feed massively, change water

Feed massively, change water

Then a decade goes by and you're having to dremel out the sps in a wasteful manner

 

[Reefbuds]

Lots of good stuff here guys!

 

[Reefbuds]

So now my nitrates are testing very high but the tank looks healthier than ever. This seems to be on track with nitrates not being an incredibly bad thing at least.