Why Is There Still a Mix Messages about Nitrates level?

[Piranhapat]

It seems everybody as different opinions on Nitrates levels. Is it me or just my imagination. I understand that every tank is different. But let's make this simple. If we talk about SPS tank only with fish. I read people keeping they tanks from 0-5 ppm and 5 ppm-10 and 10-30ppm. And even higher. So I know what works best in your tank you will run your nitrates at that level. We know higher nutrients you have better color. Why do we have different success with a higher nitrate and same with a lower nitrate level? I used to run my tank at 30 ppm never had a problem. But why are we chasing numbers and wanted lower numbers. Is the ideal 05-10 ppm range?

 

[Martin Kuhn]

Two things

- tanks like a STABLE N3/PO4 level. Corals adapt to a certain concentration. This is of special importance once you buy animals. If they come from a ULN tank and you bring them in a tank with higher nutrient level, they will get darker and more brownish in the beginning. But they will also adapt to your tanks nutrient situation as long as it is stable and not on a too high level

- ULN leads to „no brownish“ color of the zooxantelles. They are „not visible“. So you optically perceive the remaining colors more „intense“

In Tanks with some nutrients, the overall colors are more intense, but you might even not perceive as „ultra shiny“ as you have partially brownish color also.

..... depends on what coloring you like to achieve

 

[Randy Holmes-Farley Verified Community Expert]

It seems everybody as different opinions on Nitrates levels. Is it me or just my imagination. I understand that every tank is different. But let's make this simple. If we talk about SPS tank only with fish. I read people keeping they tanks from 0-5 ppm and 5 ppm-10 and 10-30ppm. And even higher. So I know what works best in your tank you will run your nitrates at that level. We know higher nutrients you have better color. Why do we have different success with a higher nitrate and same with a lower nitrate level? I used to run my tank at 30 ppm never had a problem. But why are we chasing numbers and wanted lower numbers. Is the ideal 05-10 ppm range?

I don't agree with your premise that "We know higher nutrients you have better color. ". Too low and too high of nutrients each have issues (pale colors at low nutrients, browninsh colors at high nutrients).

One cannot give a fixed "ideal" for a variety of reasons.

First is, what is the primary goal? Fast growth, or better color? Faster growth of many SPS comes from higher alkalinity (and pH) and under those conditions, one needs a lot of N and P or you risk burnt tips, perhaps because the organic tissue grows too slowly to keep up with skeletal growth.

Second reason you can't give an ideal is because it depends on how much organic sourced N and P is present. In the ocean, corals get a lot of N and P from foods. So they thrive in a very low free nitrate and phosphate environment. In a reef tank, the relative reliance on these different forms depends on what you are feeding.

With methods such as zeovit they use very low nitrate and phosphate values to prevent zooxanthellae browning of corals. To offset the low nitrate, they provide N in organic forms, such as amino acids. How much amino acid you add will determine how much reliance corals may have on nitrate as a source of N. That, in turn, impacts what is an "optimal" nitrate level.

Finally, nutrients can have substantial impacts on pests such as green hair algae. If you keep nutrients very low you can reduce the growth of some of these pests.