NO3 and PO4 and it's relationship to lighting

[Punchanello]

I have had to go fallow twice and my corals have been starved despite my best efforts and completely paled out. I've now reintroduced a handful of fish in my 130 gallon. I've just started to get an NO3 reading but no PO4 with Salifert test kits. I use a 4 bulb t5 ATI Powermodule which also has 4 banks of 75 watt LED clusters. I run the T5 at full power 11 hours a day and the LEDs for about 13 hours including an hour ramp up and down.

I am starting to notice some colour coming back. However, I have notice on the top tier of my rockwork that on some SPS, the shaded areas are starting to colour up, but the areas that face the light directly are still very pale and have been for some time.

This got me to wondering whether extremely low NO3 and PO4 can cause SPS to pale and even bleach in high light environments. Has this been the experience of other SPS keepers?

Also, should I move these corals to lower light areas or just wait until I bring up my inorganic nutrients to a respectable level?

 

[Reefahholic]

I have had to go fallow twice and my corals have been starved despite my best efforts and completely paled out. I've now reintroduced a handful of fish in my 130 gallon. I've just started to get an NO3 reading but no PO4 with Salifert test kits. I use a 4 bulb t5 ATI Powermodule which also has 4 banks of 75 watt LED clusters. I run the T5 at full power 11 hours a day and the LEDs for about 13 hours including an hour ramp up and down.

I am starting to notice some colour coming back. However, I have notice on the top tier of my rockwork that on some SPS, the shaded areas are starting to colour up, but the areas that face the light directly are still very pale and have been for some time.

This got me to wondering whether extremely low NO3 and PO4 can cause SPS to pale and even bleach in high light environments. Has this been the experience of other SPS keepers?

Also, should I move these corals to lower light areas or just wait until I bring up my inorganic nutrients to a respectable level?

Absolutely low & zero numbers (NO3/PO4) can pale and kill SPS. Have you considered dosing.? You need to. Look into LoudWolf NO3/PO4 products. Best of luck! I have both.

 

[Punchanello]

Do you think there is a relationship between nutrient levels and PAR in relation to coral health?

 

[SeaDweller]

Do you think there is a relationship between nutrient levels and PAR in relation to coral health?

I think you’re overthinking it, bud.

 

[Punchanello]

I think you’re overthinking it, bud.

I hope so, I just don't understand why the shaded undersides of some of my SPS are starting to colour up nicely but the top sides are pale.

 

[LARedstickreefer]

High PAR and unusually low “nutrients” aren’t a good combo. I’d turn down your PAR or I’d up the “nutrients”.

Zooxanthellea need their building blocks.

 

[SeaDweller]

I hope so, I just don't understand why the shaded undersides of some of my SPS are starting to colour up nicely but the top sides are pale.

Probably too much light and not enough food, just like you originally thought.

 

[Graffiti Spot]

I have seen a lot of led tanks that use a lot of light and the top of the acropora facing the light will be much paler than the underside. I would feed more but all the tanks had pretty good growth, because the owners knew how to run a lot of led and keep the corals happy. I think feeding more quality food will help.

 

[Bpb]

You’re on the right track of thinking, though there isn’t an absolute ratio of par reading to specific nutrients levels you should shoot for. Just generally speaking, par, alkalinity, and nutrients should tend in the same direction. If you’re running consistently low nutrient levels, jd consider reducing your alkalinity into the low 7’s/high 6’s, and reduce your photoperiod and intensity a good bit. If I were running near zero on N &P I would be shooting for 6.8-7 dkh and 200-300 par at absolute most

 

[jda]

I disagree completely. I run MH and have anywhere from 300 (bottom) to 750+ PAR and I keep my N at .1 and P at .005 to .01 along with 6.8 to 7.0 alk - basic ocean levels. I have a theory that light matters... not quantity, but quality. The basis is that you need to keep N and P higher with some types of cut-spectrum light sources so that the coral "slows" down - N and P are growth inhibiting as they climb to every creature at different levels.

More detail of my theory:
https://www.reef2reef.com/threads/c...radion-nitrate-phosphate.620765/#post-6214466
Even more:
https://www.reef2reef.com/threads/c...radion-nitrate-phosphate.620765/#post-6214773

Where ever you are at, you should be using a Hannah Ultra Low Phosphorous for P. I am constantly at 1 to 3 ppb. Salifert is as good as it gets for nitrate. I would turn the LEDs down in that Powermodule... they have not proven to be all that high of quality... best results seem to come with the T5s doing the heavy lifting and the LEDs filtered in for some color and dusk/dawn (I have never used one, so take that FWIW).

If you are running GFO, LC, Organic Carbon or other chemicals or media, then stop... they can drive you too low. Natural means to get to NSW levels have never been a problem.

For reference, here are my colors and corals under the MH, .1N and .oo5 to .01P. Sorry for the bad iPhone pics:


Album: https://flic.kr/s/aHsmEPiBrD

 

[jda]

Probably too much light and not enough food, just like you originally thought.

N and P are not "food." They provide no energy. They are building blocks of life needed to make new tissue and also to repair old (although most coral can recycle some of these, AFAICT). Once you have a surplus of any measurable amount, then more does no good. Light provides food through the Zoox - sugars. Quality matters. Quantity matters. The level depends on the actual coral. IF a coral can catch a carbon rich food, like a live zooplankton, then that can be food too - not much evidence that an acropora gets anything out of this... there is a little bit of evidence that poci and stylos can... there is a lot of evidence that LPS can do this.

IMO, the paleness is from some bad spectrum in the LEDs being run too high.

 

[Neoalchemist]

I would listen to @jda . His (If I remember correctly) 20+ plus year old systems are bursting with happy sps.

 

[MnFish1]

Do you think there is a relationship between nutrient levels and PAR in relation to coral health?

Yes - but alkalinity is also involved. Up to a point, with a higher alkalinity - there can be more growth and thus more nutrient use . Likewise, with more light - which can also (up to a point) cause more growth there can be more nutrient use. With higher alk AND higher light this can be even worse - and seems (to me) to be where people have problems

 

[MnFish1]

N and P are not "food." They provide no energy. They are building blocks of life needed to make new tissue and also to repair old (although most coral can recycle some of these, AFAICT). Once you have a surplus of any measurable amount, then more does no good. Light provides food through the Zoox - sugars. Quality matters. Quantity matters. The level depends on the actual coral. IF a coral can catch a carbon rich food, like a live zooplankton, then that can be food too - not much evidence that an acropora gets anything out of this... there is a little bit of evidence that poci and stylos can... there is a lot of evidence that LPS can do this.

IMO, the paleness is from some bad spectrum in the LEDs being run too high.

Technically correct - but - 'FOOD' is broken down into 'the building blocks of life'. Have you ever heard of 'Adenosine triphosphate'? Which is one of the main energy producers in the cell. Without phosphate - all of the 'food' (glucose) in the world would not help. I agree with you though - that once the Nitrate/Phosphate levels become higher than whats needed - it doesnt matter - but since you didnt quote which post you were referring to - it was a little confusing. The OP felt his levels were at 0 (or low) which is what people were responding to.

 

[Dana Riddle]

Alkalinity and rates of photosynthesis examined through PAM fluorometry.
https://www.advancedaquarist.com/2016/9/aafeature

 

[jda]

I am going to purposefully be non-technical. If you have detectable levels of N and P, then adding more will do no good - any excess is excess. I have never suggested that people have zero, or otherwise try and get below NSW levels, which is why I do not choose to use ZeoVit - this is walking a fine line at best and could be dangerous at worst. If you add more light, then usually growth can increase with the increased sugars provided that the N and P levels stay available with the increased demand/uptake. Adding more N and P does not allow your coral to "do more" but adding in more light can indeed allow your corals to "do more" to a point, but quality matters it seems.

When using natural methods, the system can handle this on it's own. Aragonite binds P and can act as a reservoir. Even with NSW levels of 1 to 3 ppb of phosphate, there is a good amount bound up in the rocks and sand. If the tank goes on a growth spurt, the rock and sand will release some to have the water be at equilibrium again. Same is true with N, but in a different way. The bacteria in the sand bed and rocks will convert no3 to n gas, but it always leaves some that cannot reach those areas. Combine this with Ammonia/Ammonium being the preferred source of nitrogen for most corals and algae and they always find a way to have enough nitrogen while allowing the anoxic bacteria to clean up the scraps that make it through the N cycle.

All of this points me back to cut-spectrum lighting... but I have no idea if my supposition is correct... and it probably isn't but I am not smart enough to know why.

 

[SeaDweller]

N and P are not "food." They provide no energy. They are building blocks of life needed to make new tissue and also to repair old (although most coral can recycle some of these, AFAICT). Once you have a surplus of any measurable amount, then more does no good. Light provides food through the Zoox - sugars. Quality matters. Quantity matters. The level depends on the actual coral. IF a coral can catch a carbon rich food, like a live zooplankton, then that can be food too - not much evidence that an acropora gets anything out of this... there is a little bit of evidence that poci and stylos can... there is a lot of evidence that LPS can do this.

IMO, the paleness is from some bad spectrum in the LEDs being run too high.

Thanks for the correction, available nutrients is probably a better phrase I was looking for.

 

[Bpb]

Serious questio JDA, If I am reading your theory correctly, and any excess is excess, why do we tend to observe problems when there is extreme excess versus a low to moderate amount?

 

[MnFish1]

I am going to purposefully be non-technical. If you have detectable levels of N and P, then adding more will do no good - any excess is excess. I have never suggested that people have zero, or otherwise try and get below NSW levels, which is why I do not choose to use ZeoVit - this is walking a fine line at best and could be dangerous at worst. If you add more light, then usually growth can increase with the increased sugars provided that the N and P levels stay available with the increased demand/uptake. Adding more N and P does not allow your coral to "do more" but adding in more light can indeed allow your corals to "do more" to a point, but quality matters it seems.

When using natural methods, the system can handle this on it's own. Aragonite binds P and can act as a reservoir. Even with NSW levels of 1 to 3 ppb of phosphate, there is a good amount bound up in the rocks and sand. If the tank goes on a growth spurt, the rock and sand will release some to have the water be at equilibrium again. Same is true with N, but in a different way. The bacteria in the sand bed and rocks will convert no3 to n gas, but it always leaves some that cannot reach those areas. Combine this with Ammonia/Ammonium being the preferred source of nitrogen for most corals and algae and they always find a way to have enough nitrogen while allowing the anoxic bacteria to clean up the scraps that make it through the N cycle.

All of this points me back to cut-spectrum lighting... but I have no idea if my supposition is correct... and it probably isn't but I am not smart enough to know why.

Thanks for explaining - I wonder if an extremely low N and P (which we measure) reflect extremely low levels of other 'nutrients'/organics that also benefit certain corals. In any case IME - to answer the OP - there is a relationship between light and coral growth - too little or too much can be detrimental - and that levels of nutrients./alkalinity play a role. Haven't gotten through @Dana Riddle's article yet (butI think I'vereadit before

 

[jda]

Too much N and P is a poison to any organic tissue. The amount varies from creature to creature. Sometimes the effects are linear and sometimes they are exponential. For coral, there is a wide range. Coralline will be seriously hindered at pretty low numbers like around .1p and 2-3P (or so) where it won't quit growing, but will slow quite a bit. Some SPS can handle N up to 50 whereas others will stop growing much at all and even some will STN and die.

Since too much is no good, then adding excess to excess just seems like a bad plan to me. If you have excess then you don't need more excess.