Randy’s Thoughts on Nutrient Target Ranges

[rishma]

@Randy Holmes-Farley…thinking about phosphate/nitrate levels and algae. A friend has a seriously neglected tank with a lot of hair algae. I tested phosphates and it hit top of range on my checker. He has lots of happy herbivores.

My plan is to help lower nutrients (slowly). I think from our past exchanges you would do something different. Thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley…thinking about phosphate/nitrate levels and algae. A friend has a seriously neglected tank with a lot of hair algae. I tested phosphates and it hit top of range on my checker. He has lots of happy herbivores.

My plan is to help lower nutrients (slowly). I think from our past exchanges you would do something different. Thoughts?

There’s nothing wrong with lowering nutrients if they are very high. How high?

Are there corals on the tank?

It will be interesting to lower it slowly and see if algae begins to lose the battle before nutrients get to my lower limit suggestion. :)

 

[Hans-Werner]

@Randy Holmes-Farley…thinking about phosphate/nitrate levels and algae. A friend has a seriously neglected tank with a lot of hair algae. I tested phosphates and it hit top of range on my checker. He has lots of happy herbivores.

My plan is to help lower nutrients (slowly). I think from our past exchanges you would do something different. Thoughts?

Would be interesting to follow this, how you lower nutrients and what the effects are, maybe in an own thread. This would also give the opportunity to give some advice if you want.

 

[rishma]

There’s nothing wrong with lowering nutrients if they are very high. How high?

Are there corals on the tank?

It will be interesting to lower it slowly and see if algae begins to lose the battle before nutrients get to my lower limit suggestion. :)

Would be interesting to follow this, how you lower nutrients and what the effects are, maybe in an own thread. This would also give the opportunity to give some advice if you want.

I cannot do proper thread in it. I am visiting out of state and my friend is not online or much of a tester of water. I am struggling to figure out how lower his nutrients carefully with out being here to test and observe.

 

[Hans-Werner]

I cannot do proper thread in it. I am visiting out of state and my friend is not online or much of a tester of water. I am struggling to figure out how lower his nutrients carefully with out being here to test and observe.

It would be sufficient to tell what you are doing and seing, for example adding adsorber etc., but please don't feel pushed or preasured to do this.

 

[Tony Thompson]

Thanks @Randy Holmes-Farley , its a gem to find well written and thought out articles amongst the noise these days.

I am very grateful that many like yourself take the time and effort to right such articles.

However I inevitably come to the conclusion that we know so little about such a complex subject as a living reef aquarium. The huge variables and limits of detection of such a complex flux of a living and evolving environment just compound our ability to make solid recommendations.

However its still fascinating to ponder, propose and hypothesise.

All the best from across the pond, Tony.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks @Randy Holmes-Farley , its a gem to find well written and thought out articles amongst the noise these days.

I am very grateful that many like yourself take the time and effort to right such articles.

However I inevitably come to the conclusion that we know so little about such a complex subject as a living reef aquarium. The huge variables and limits of detection of such a complex flux of a living and evolving environment just compound our ability to make solid recommendations.

However its still fascinating to ponder, propose and hypothesise.

All the best from across the pond, Tony.

You're welcome and thanks.

I agree that reef tanks are very complex situations, and the best we can do is to try to be logical and thoughtful about how we care for them. :)

 

[vlangel]

Thank you @Randy Holmes-Farley and all of you who contributed to this thread. I perused it pretty fast but hope to go back and digest it more fully to gain more insight. I kind of know what works for my high nutrient system but I don't know all the ins and outs of why. I am a more intuitive reefer than I am a detailed watch the parameters kind of gal.

 

[TTipsyDragon]

I was just thinking to my self the other day and glad you wrote an article about it. I run a 112 gallon tank with no skimmer and no refugium which naturally brings up my nutrients levels. I was running low N and P when I had a working refugium. The problem was it was powered by GHA, so I turned it off to nuke the GHA which then rose my tank up to high nutrients.

What I observed was happier corals, further extensions, color improvements and happy fish / inverts. Even triggered my feather duster to successfully reproduce.

 

[CHSUB]

happy fish / inverts

Seems like Confirmation bias..

 

[Superlightman]

I think it can't be ascribed to one or two factors. It is a complex system and everything plays a role, lighting, trace elements, dissolved nutrients, biology, particulate nutrients etc..

LED seems a different quality in lighting compared to metal halides and fluorescent lamps wich I ascribe to the 450 nm peak.

Addition: Particulate nutrients also seem to have a special quality for corals since after feeding they show no net uptake of dissolved reactive phosphate from the water for some time.

Could you elaborate this point with the light and 450nm?

 

[Hans-Werner]

Could you elaborate this point with the light and 450nm?

I think it is a widespread misconception that plants, algae and corals "judge" light by intensity of photosynthesis or by a wide light spectrum. This is not the case.

Plants and algae use photoreceptor proteins with sensitivity in a +/- narrow bandwidth of the light spectrum. These photoreceptor proteins are cryptochromes and photochromes, both with maximum sensitivity in ca. 450 nm of the visible spectrum, and phytochrome with sensitivity in light red or dark red spectrum of light.

Blue light of 450 nm plays a major role in photoadaptation of algae and regulation of many other biochemical mechanisms of diverse organisms.

Blue light around 450 nm directly has the largest effect in daytime polyp contraction of corals (and here). It regulates circadian rhythms in most organisms and keeps them awake, that's why I don't recommend blue light for "moonlight". Real moonlight is in fact more yellow and red than sunlight. (See spectrum here. I have photographed under moonlight. It really is more yellow and red and less blue at "daylight" camera setting. The blue moonlight in movies and images is fake to imitate the human perception.)

Ironically it is exactly the blue light around 450 nm where LED lighting and T5 and metal halide lighting differ most.

In LED lighting, around 450 nm is the wavelength of royal blue LEDs and the activation light in white LEDs, causing a 450 nm peak of most white LEDs except some warm white LEDs.

In T5 and metal halides 450 nm is either the wavelength that is lacking from the beginning or it is the wavelenght that gets burned out and almost lost first.

Since 450 nm gets burned out first in T5 and metal halides, changing tubes or bulbs in lamps may cause major adaptation problems in corals which is known as light shock of corals.

 

[rishma]

that's why I don't recommend blue light for "moonlight". Real moonlight is in fact more yellow and red than sunlight. (See spectrum here.

I have spent time thinking a researching what an appropriate spectrum would be for moonlight over my reef. I learned what you shared, which is the color of moonlight is definitely shifted to the warm end of the spectrum. However, moonlight measure at depth with have a distinctly blue spectrum except on very shallow reefs. So depending on type of reef you are trying to emulate, blue might be a good choice.

 

[Hans-Werner]

I have spent time thinking a researching what an appropriate spectrum would be for moonlight over my reef. I learned what you shared, which is the color of moonlight is definitely shifted to the warm end of the spectrum. However, moonlight measure at depth with have a distinctly blue spectrum except on very shallow reefs. So depending on type of reef you are trying to emulate, blue might be a good choice.

I have never used moonlights over longer periods of time, so I asked in a German reef forum what reef tank moonlights are for. The responses were 100 % their moonlight is not regulated according to moon phases but are on the whole nights and always with the same intensity.

I asked what they are used for, and the responses were, to keep fish from jumping out of the tank when being frightened or the lights go on and to watch the fish and critters at night. For none of these "applications" blue light is appropriate. Human seeing is not very sensitive to blue light and I find the recognizability bad under blue light, even at sufficient strength. Eyesight of reef fish is not too different from that of humans.

In my eyes it is really bad to keep fish and other organisms, even corals, under blue "moonlight" that mainly has the function to keep them awake and disturb circadian clocks.

In my eyes it even throws up the question whether it is animal cruelty. Exposing prisoners to light around the clock to disrupt their circadian clock and the sensing for time of day is torture.

 

[rishma]

I have never used moonlights over longer periods of time, so I asked in a German reef forum what reef tank moonlights are for. The responses were 100 % their moonlight is not regulated according to moon phases but are on the whole nights and always with the same intensity.

I asked what they are used for, and the responses were, to keep fish from jumping out of the tank when being frightened or the lights go on and to watch the fish and critters at night. For none of these "applications" blue light is appropriate. Human seeing is not very sensitive to blue light and I find the recognizability bad under blue light, even at sufficient strength. Eyesight of reef fish is not too different from that of humans.

In my eyes it is really bad to keep fish and other organisms, even corals, under blue "moonlight" that mainly has the function to keep them awake and disturb circadian clocks.

In my eyes it even throws up the question whether it is animal cruelty. Exposing prisoners to light around the clock to disrupt their circadian clock and the sensing for time of day is torture.

I understand the point you are making and it’s not bad advice, but I don’t entirely agree.

Some moonlights available now do follow the moon phases. The one I use follows the moon phases and uses a cosine based function that is a good approximation of moon intensity through the phases. It might have some benefits. The one I use is also corrected for latitude and longitude which you can use to simulate a specific location. I believe some labs working on coral/fish spawning are experimenting with this.

I feel pretty confident I am using an appropriate spectrum for a deeper reef moonlight. I put a bit of effort into it. I do worry about intensity so I am at an extremely low peak intensity, fractions of a watt.

Does it do anything good for my tank? Probably not. But I find it interesting and unlikely to do harm in my application.

 

[Hans-Werner]

I understand the point you are making and it’s not bad advice, but I don’t entirely agree.

Some moonlights available now do follow the moon phases. The one I use follows the moon phases and uses a cosine based function that is a good approximation of moon intensity through the phases. It might have some benefits. The one I use is also corrected for latitude and longitude which you can use to simulate a specific location. I believe some labs working on coral/fish spawning are experimenting with this.

I feel pretty confident I am using an appropriate spectrum for a deeper reef moonlight. I put a bit of effort into it. I do worry about intensity so I am at an extremely low peak intensity, fractions of a watt.

Does it do anything good for my tank? Probably not. But I find it interesting and unlikely to do harm in my application.

Yes, this is ok in my eyes but it is a completely different application than I am talking about.

The kind of application you do may have benefits. Other light sources may disturb or lessen the benefit, i. e. if you watch TV late at night in the same room.

 

[Hans-Werner]

@rishma , does your moonlight program also take into account that the Moon shines at different times of the night (and day)? I mean, at new Moon the Moon is lit by the Sun from the back and is at the same side as the sun. Following new Moon the waxing Moon shines only in the evening before sinking. The full moon shines brightest at midnight, as it is opposed to the Sun, and the subsequent phases of the waning Moon shine brightest after midnight until they visually get closer to the Sun, rising in the morning before new Moon.

 

[rishma]

@rishma , does your moonlight program also take into account that the Moon shines at different times of the night (and day)? I mean, at new Moon the Moon is lit by the Sun from the back and is at the same side as the sun. Following new Moon the waxing Moon shines only in the evening before sinking. The full moon shines brightest at midnight, as it is opposed to the Sun, and the subsequent phases of the waning Moon shine brightest after midnight until they visually get closer to the Sun, rising in the morning before new Moon.

It’s a complete moon simulation. The time of moon rise, moon set, intensity, etc matches nature and shifts based on the calendar, time, and the chosen latitude and longitude. I just use the latitude longitude of my house, so it matches the moon I see at home.

 

[tripdad]

It’s a complete moon simulation. The time of moon rise, moon set, intensity, etc matches nature and shifts based on the calendar, time, and the chosen latitude and longitude. I just use the latitude longitude of my house, so it matches the moon I see at home.

Please share what you are using as it sounds interesting to me. I stopped overnight lighting(moon) because i observed odd behaviour of a couple of fish. I would like to have a "correct" moonlight. Thanks

 

[dvgyfresh]

Orphek lights have a moon feature that matches based on your geographic location , they have write ups claiming the benefits. When moonlight is on nothing is open but I can view the tank, it is not enough light for photosynthesis