What is PAR and how much do we need?

[Dana Riddle]

I see messages implying PAR values exceeding known Saturation Points are OK. In many cases they are not - a coral can be bleached and it is impossible to visually judge this. A non-intrusive chlorophyll meter is needed unless one wants to sacrifice a portion of the coral and extract photopigments for analyses. As far as I know, I am the only hobbyists owning one of the $3,000 meters. If you have one (Opti-Sciences) please drop me a line. Generation of reflective proteins might add some protection against excessive light. Perhaps some of the fluorescent proteins do as well. In the case of branching corals, the exposed areas can be bleached while the shaded portions have a healthy zoox population.

 

[ShepherdReefer]

So much to learn. Love it.

 

[Freenow54]

The Photosynthetic Active Radiation (PAR) is a term used within the reef tank community when talking about lighting. Lighting is one of the most importing aspects of the reef aquarium, partly because many aquarium organisms require lighting to maintain or increase their growth and too high of a PAR can increase the growth of unwanted algae. Photosynthetic is the process by which these organisms transform light energy into food. Corals have tiny plants called zooxanthellae living within their tissue and so together they are called photosynthetic. The PAR is the measurement of light emission within the photosynthetic range of 400-700nm (nm is Nano-meter).

There are a few ways we can measure the lighting in the aquarium, such as lumens and lux meters but we are talking about PAR. Most, if not all, PAR meters are actually favorited within the reef community because they work well with LED lighting. I purchased an Apogee MQ-510 but I think any LED meter will be fine.

When I purchased this meter, there was no instruction on how to use the meter but the instructions can be viewed from Apogee’s website. You can search the internet, especially YouTube, and find different ways of testing…It is really easy. One item to note while using the meter, the PAR displayed will have a fluctuation range of reading.

For me, just starting out adding corals in my saltwater aquariums, my knowledge was not up to the challenge. My main problem was when purchasing corals from either an online store or local store, the descriptions stated the required lighting needs such as low, moderate, high, or extreme light. But what do these levels mean? Without a discussion on more specifics information regarding PAR, I want to talk about these few requirement levels.

In general, corals with low values are considered to less than 100 and high values are generally over 250/300, so that means anything in the middle is medium values.

• Soft corals are low values
• LPS corals are medium values
• SPS corals are high values

From my research, the below table has a little more detail:

Species	Light Level	PAR Range
Low light LPS	Low	50 - 100
Soft Corals	Low – Moderate	50 - 200
LPS	Moderate	100 - 200
Derasa Clams, Anemones SPS	High	200 - 300
Montipora and other SPS	Intense	300 - 400
Crocea, Maxima Clams, Acro	Extreme	400 – 500+

Recap:

• Low < 100
• Moderate 100 – 200
• High 200 – 300
• Intense 300 – 400
• Extreme > 400

With this rule of thumb, most corals will adapt to different levels when given time to acclimate. Such as LPS corals can handle greater PARs up to 500, and soft corals will adjust to PAR over 200 with adequate time to adjust so they can adapt to a wide range of lighting over time.

The lighting schedule can also play a huge role in the success of the reef aquarium regarding PAR levels. I tried to match the Sun with the respect to the rotation around the Earth. I set up my LED lighting on Apex Fusion to mirror Sun’s rise and fall. Here is what my schedule looks like.

The schedule has changed a few times since the beginning and I am sure it will change again.

Chasing PAR values can be time-consuming but can be more beneficial and observe these values based on individual needs and reactions. When purchasing a new coral and knowing the PAR before adding a coral into the new population can be a huge advantage. Something else to consider if no PAR meter is available, in the lower lights levels corals will lose their color and grow slower but if too bright, the corals will bleach and die faster.

I really could use some direction as to a publication regarding corals. My knowledge is very limited. I try to follow links but the acronyms, and names mean nothing to me at this point

 

[Freenow54]

The Photosynthetic Active Radiation (PAR) is a term used within the reef tank community when talking about lighting. Lighting is one of the most importing aspects of the reef aquarium, partly because many aquarium organisms require lighting to maintain or increase their growth and too high of a PAR can increase the growth of unwanted algae. Photosynthetic is the process by which these organisms transform light energy into food. Corals have tiny plants called zooxanthellae living within their tissue and so together they are called photosynthetic. The PAR is the measurement of light emission within the photosynthetic range of 400-700nm (nm is Nano-meter).

There are a few ways we can measure the lighting in the aquarium, such as lumens and lux meters but we are talking about PAR. Most, if not all, PAR meters are actually favorited within the reef community because they work well with LED lighting. I purchased an Apogee MQ-510 but I think any LED meter will be fine.

When I purchased this meter, there was no instruction on how to use the meter but the instructions can be viewed from Apogee’s website. You can search the internet, especially YouTube, and find different ways of testing…It is really easy. One item to note while using the meter, the PAR displayed will have a fluctuation range of reading.

For me, just starting out adding corals in my saltwater aquariums, my knowledge was not up to the challenge. My main problem was when purchasing corals from either an online store or local store, the descriptions stated the required lighting needs such as low, moderate, high, or extreme light. But what do these levels mean? Without a discussion on more specifics information regarding PAR, I want to talk about these few requirement levels.

In general, corals with low values are considered to less than 100 and high values are generally over 250/300, so that means anything in the middle is medium values.

• Soft corals are low values
• LPS corals are medium values
• SPS corals are high values

From my research, the below table has a little more detail:

Species	Light Level	PAR Range
Low light LPS	Low	50 - 100
Soft Corals	Low – Moderate	50 - 200
LPS	Moderate	100 - 200
Derasa Clams, Anemones SPS	High	200 - 300
Montipora and other SPS	Intense	300 - 400
Crocea, Maxima Clams, Acro	Extreme	400 – 500+

Recap:

• Low < 100
• Moderate 100 – 200
• High 200 – 300
• Intense 300 – 400
• Extreme > 400

With this rule of thumb, most corals will adapt to different levels when given time to acclimate. Such as LPS corals can handle greater PARs up to 500, and soft corals will adjust to PAR over 200 with adequate time to adjust so they can adapt to a wide range of lighting over time.

The lighting schedule can also play a huge role in the success of the reef aquarium regarding PAR levels. I tried to match the Sun with the respect to the rotation around the Earth. I set up my LED lighting on Apex Fusion to mirror Sun’s rise and fall. Here is what my schedule looks like.

The schedule has changed a few times since the beginning and I am sure it will change again.

Chasing PAR values can be time-consuming but can be more beneficial and observe these values based on individual needs and reactions. When purchasing a new coral and knowing the PAR before adding a coral into the new population can be a huge advantage. Something else to consider if no PAR meter is available, in the lower lights levels corals will lose their color and grow slower but if too bright, the corals will bleach and die faster.

Is there a publication that I can get to expand my knowledge on coral?

 

[rgulrich]

Is there a publication that I can get to expand my knowledge on coral?

If You're Serious About Lighting, Know This

Per @GoVols suggestion: Lighting for reef aquaria can be as simple or complex as you wish to make it. If you’re really serious about lighting, these are some of the terms you might want to be familiar with: Accessory Pigment: A photopigment that absorbs light and transfers it to chlorophyll a...

www.reef2reef.com

A sticky on this lighting forum started by Dana. Good read for start with lighting terminology. After that, ask away on specific areas of focus.
Cheers, Ray

 

[MnFish1]

Is there a publication that I can get to expand my knowledge on coral?

Are you talking about a 'general' publication about corals, or a publication about 'coral lighting'?

 

[MnFish1]

I see messages implying PAR values exceeding known Saturation Points are OK. In many cases they are not - a coral can be bleached and it is impossible to visually judge this. A non-intrusive chlorophyll meter is needed unless one wants to sacrifice a portion of the coral and extract photopigments for analyses. As far as I know, I am the only hobbyists owning one of the $3,000 meters. If you have one (Opti-Sciences) please drop me a line. Generation of reflective proteins might add some protection against excessive light. Perhaps some of the fluorescent proteins do as well. In the case of branching corals, the exposed areas can be bleached while the shaded portions have a healthy zoox population.

Interesting. So - it was always my impression that bleaching meant 'turn white'. Are you saying that the tops turn 'white' and the shaded areas remain 'colorful' - or are you saying that the top areas (under the higher par) a lighter colored than the bottom? Would you be able to post a picture/example? Thanks!

 

[oreo54]

Is there a publication that I can get to expand my knowledge on coral?

Lighting the Reef Aquarium Part 6 - Coral Coloration – A Primer •Orphek

Lighting the Reef Aquarium Part 6: Coral Coloration – A Primer By Dana Riddle ,This colorful Acropora species is not fluorescent – the proteins it contains preferentially reflect red and blue light, making it appear purple.

orphek.com

Start here and prob. another dozen Daba links.

 

[Freenow54]

Are you talking about a 'general' publication about corals, or a publication about 'coral lighting'?

All inclusive, But anything would be a step in the right direction.

 

[oreo54]

Interesting. So - it was always my impression that bleaching meant 'turn white'. Are you saying that the tops turn 'white' and the shaded areas remain 'colorful' - or are you saying that the top areas (under the higher par) a lighter colored than the bottom? Would you be able to post a picture/example? Thanks!

Dying coral reefs turn vibrant neon colors in apparent last-ditch effort to survive

Coral reefs on the brink of death are attempting to send a survival signal, via fluorescent neon colors.

www.cbsnews.com

 

[Freenow54]

Thank you for the reply. As I have stated in other posts. I take the Responsibility of Life in my tank very seriously. I have first hand experience of what can go wrong, after buying an :" established tank " per my son, and brining it out of the abyss. I do not have a chlorophyll meter. I was reading a thread, and assumed I could get close with a Lux meter, which I just bought, and now realize it was a big mistake. Now I am going to get an Apogee MQ510. What brought my attention to the deeper part of the subject is the PAR posting page you started, and saw the values. Which are much lower than I expected. My situation is I am staring a new tank, I have cycled it, and am now adding fish. Per BRS video I am leaving the lights off for now. They are a pair of Aquanest M8's. So has preset LPS, and SPS settings. I asked the question about what you do if you have different coral with no answer. I understand how basic my information is at this point. Regarding the tank and the light height amongst dozens of other factors. Could you expand on " generation of reflective proteins"? My Interest was raised by the post from ShepherdReefer

 

[DarthChaos]

Never measured PAR...probably never will

How do I get my corals to grow so well? I let THEM tell me what they need, instead of assuming....I know what's best for them

I've literally put "low" light corals, up with my SPS and had them explod with growth. The best indicators of good lighting - is paying attention to your tank.

IMO - people spend FAR too much time concerned about lighting (and it's not their fault....company's push "good" lighting hard). Anyone's who's who's reefing....for more than a few months, as seen epic tanks - in even, the most of basic lighting (we talking like stock BioCube LEDs)

Lighting....Ive found, is the easiest part of reefing. 1/4 of a successful tank...is lighting - people get so wrapped up in lighting, the miss just feeding their corals properly and ensuring their levels are strong.

 

[Freenow54]

Are you talking about a 'general' publication about corals, or a publication about 'coral lighting'?

Seems my post got lost. One that distinguishes the different family's for general knowledge would be a start. However I am after specific information as to that corals lighting requirements as well

 

[Freenow54]

Never measured PAR...probably never will

How do I get my corals to grow so well? I let THEM tell me what they need, instead of assuming....I know what's best for them

IMO - people spend FAR too much time concerned about lighting (and it's not their fault....company's push "good" lighting hard). Anyone's who's who's reefing....for more than a few months, as seen epic tanks - in even, the most of basic lighting (we talking like stock BioCube LEDs)

Lighting....Ive found, is the easiest part of reefing. 1/4 of a successful tank...is lighting - people get so wrapped up in lighting, the miss just feeding their corals properly and ensuring their levels are strong.

Well I am not in the position to argue. I have a starter tank that is 10 years old at least that I inherited. My son kept throwing money at it fish, and coral. We lost a lot of the coral. Why? Now I realize could have been a lot of things. Also I put a " razor " light on it guessed as to the levels. Some coral thrived and multiplied Why? I assumed since my parameters are spot on that it was lighting. I just want to have every step covered. I spent $ 500 on an RO system, and DI filter for instance. Made a huge improvement on the tank I am talking about

 

[DarthChaos]

Well I am not in the position to argue. I have a starter tank that is 10 years old at least that I inherited. My son kept throwing money at it fish, and coral. We lost a lot of the coral. Why? Now I realize could have been a lot of things. Also I put a " razor " light on it guessed as to the levels. Some coral thrived and multiplied Why? I assumed since my parameters are spot on that it was lighting. I just want to have every step covered. I spent $ 500 on an RO system, and DI filter for instance. Made a huge improvement on the tank I am talking about

Yep....thats what I mean.

I have seen some mind blowing tanks - with lighting that, well shouldnt grow grass! Lol

You have everything from stock LEDs on a $500 tank to high-end Radions - and yet, corals grow. How? How can person A.....be as successful with their $200 reef light as person B, with their $2000 reef light?

ONE reason - corals adapt. It's crazy, how we don't give these animals more credit. Corals are extremely good at adapting to the light they receive. As long as you are meeting the "basic" needs (when it comes to lightin) - corals 100% thrive. We see it....every, single day.

As I said though.....lighting is the easiest part of the equation.

Keeping GOOD water - balancing nutrients (not too high, not too low) - maintaining minerals and elements - ensuring what corals actually use to grow, are present.....is the real key.

Its mind blowing....you'll see reefers spend THOUNSANDS of dollars on their lights - and are using an API test kit or trying to maintain stability, by dosing manually or think - the best way to grow corals, is to change your lighting schedule every other week. ;Facepalm

Reefing....IMO, is as complicated as you wanna make it.

 

[MnFish1]

Dying coral reefs turn vibrant neon colors in apparent last-ditch effort to survive

Coral reefs on the brink of death are attempting to send a survival signal, via fluorescent neon colors.

www.cbsnews.com

Thanks - I was asking Dana what he meant - but appreciate the article

 

[MnFish1]

Seems my post got lost. One that distinguishes the different family's for general knowledge would be a start. However I am after specific information as to that corals lighting requirements as well

The problem here - is that is a really general question. I would suggest to you that you go to the forum for the coral you're interested in - and just start reading 'topics'. I.e. soft corals, LPS, SPS forums. You will quickly get an idea. There is no magic IMHO. Here are a couple general points that I hope help:

1. All coral like clean water with good parameters (in general)
2. soft corals require < light than LPS requiring < than SPS corals
3. IMHO - LPS thrive with some dirty water now and then - that they can filter (like when you clean the glass)
4. I (personally) am not a believer in coral foods, additives, etc. I let the coral eat the small pieces of food - some of which I grind into very small particles
5. Lighting - (this is what I wanted clarity from the expert @Dana Riddle) - too little light is bad (long-term) - my interpretation - is that on the reef - where it can sometimes be cloudy for a week or more at a time - little light hurts growth - but not coral itself. Too much light - too quickly can cause problems. A PAR meter (which you can borrow from an LFS - or rent - or buy) can tell you where your light is at.
6. It is also my impression that the higher the alkalinity and the lower the flow - the more light-sensitive corals become.

Hope this helps some

 

[oreo54]

Thanks - I was asking Dana what he meant - but appreciate the article

Normally I wouldn't have answered but Dana seems a bit awol atm so next best thing(?).
The link not me.

A fun read...

Development of a free radical scavenging probiotic to mitigate coral bleaching

Corals are colonized by symbiotic microorganisms that exert a profound influence on the animal’s health. One noted symbiont is a single-celled alga (from the family Symbiodiniaceae ), which provides the coral with most of its carbon. During thermal stress, the algae’s photosystems are impaired...

www.biorxiv.org

Coral Fluorescent Proteins as Antioxidants

A wide array of fluorescent proteins (FP) is present in anthozoans, although their biochemical characteristics and function in host tissue remain to be determined. Upregulation of FP's frequently occurs in injured or compromised coral tissue, suggesting ...

www.ncbi.nlm.nih.gov

 

[MnFish1]

Normally I wouldn't have answered but Dana seems a bit awol atm so next best thing(?).
The link not me.

A fun read...

Development of a free radical scavenging probiotic to mitigate coral bleaching

Corals are colonized by symbiotic microorganisms that exert a profound influence on the animal’s health. One noted symbiont is a single-celled alga (from the family Symbiodiniaceae ), which provides the coral with most of its carbon. During thermal stress, the algae’s photosystems are impaired...

www.biorxiv.org

Coral Fluorescent Proteins as Antioxidants

A wide array of fluorescent proteins (FP) is present in anthozoans, although their biochemical characteristics and function in host tissue remain to be determined. Upregulation of FP's frequently occurs in injured or compromised coral tissue, suggesting ...

www.ncbi.nlm.nih.gov

thanks - appreciated - I wanted just a response from Dana on that one question - .

 

[Freenow54]

The problem here - is that is a really general question. I would suggest to you that you go to the forum for the coral you're interested in - and just start reading 'topics'. I.e. soft corals, LPS, SPS forums. You will quickly get an idea. There is no magic IMHO. Here are a couple general points that I hope help:

1. All coral like clean water with good parameters (in general)
2. soft corals require < light than LPS requiring < than SPS corals
3. IMHO - LPS thrive with some dirty water now and then - that they can filter (like when you clean the glass)
4. I (personally) am not a believer in coral foods, additives, etc. I let the coral eat the small pieces of food - some of which I grind into very small particles
5. Lighting - (this is what I wanted clarity from the expert @Dana Riddle) - too little light is bad (long-term) - my interpretation - is that on the reef - where it can sometimes be cloudy for a week or more at a time - little light hurts growth - but not coral itself. Too much light - too quickly can cause problems. A PAR meter (which you can borrow from an LFS - or rent - or buy) can tell you where your light is at.
6. It is also my impression that the higher the alkalinity and the lower the flow - the more light-sensitive corals become.

Hope this helps some

Since using RO water, and using filter media, and cloth for Nitrates it not only let me control the algae, but also my leathers which at one point I split are coming on beutifully