What's Your Lowest Successful PAR Level?

[Dana Riddle]

Years ago (in the dark ages, pun intended) we believed intense light was a prerequisite for success with corals, especially SPS. At one point, we actually tested a Fusion sulfur lamp that produced so much light that it maxed out the PAR (measured up to 20,000 micromole/m2/sec.) We know now that corals can grow quite well in low light (if other parameters are in order.) So, what's your lowest PAR that keeps a coral alive (we'll keep growth rates out of the equation for now.) It would be great if you want to mention the lamp type/spectral quality.

 

[Crabs McJones]

Years ago (in the dark ages, pun intended) we believed intense light was a prerequisite for success with corals, especially SPS. At one point, we actually tested a Fusion sulfur lamp that produced so much light that it maxed out the PAR (measured up to 20,000 micromole/m2/sec.) We know now that corals can grow quite well in low light (if other parameters are in order.) So, what's your lowest PAR that keeps a coral alive (we'll keep growth rates out of the equation for now.) It would be great if you want to mention the lamp type/spectral quality.

Well for the longest time I didn't have access to a Par meter. I have my two Kessil A360WE's over my 40 breeder, and I was scared as hell to burn or bleach my corals. So I never turned the intensity up past 30% When I finally did get a par meter, I found out that nowhere in the tank went over 80 Par. Yet I had SPS corals that were growing (very slowly, but they were growing) Jedi Mind Trick Monti, Reverse Superman Monti, Red Cap monti, Sunset monti, Tri color acro, and strawberry shortcake acro. Since then cranked it up to almost 70% and getting around 250-300 par at my SPS and everything is taking off and growing faster than I ever could have imagined.

 

[Dana Riddle]

Well for the longest time I didn't have access to a Par meter. I have my two Kessil A360WE's over my 40 breeder, and I was scared as hell to burn or bleach my corals. So I never turned the intensity up past 30% When I finally did get a par meter, I found out that nowhere in the tank went over 80 Par. Yet I had SPS corals that were growing (very slowly, but they were growing) Jedi Mind Trick Monti, Reverse Superman Monti, Red Cap monti, Sunset monti, Tri color acro, and strawberry shortcake acro. Since then cranked it up to almost 70% and getting around 250-300 par at my SPS and everything is taking off and growing faster than I ever could have imagined.

This thread will probably get off track quickly, but how did the coloration respond (intensify/weaken)? I'm seeing good coloration and growth at a PAR of around 25 (mostly blue LEDs.) This is pretty darn close to the minimum needed by corals (the compensation point) but it's working for even corals that are generally considered (falsely) 'light-loving.'

 

[Crabs McJones]

This thread will probably get off track quickly, but how did the coloration respond (intensify/weaken)? I'm seeing good coloration and growth at a PAR of around 25 (mostly blue LEDs.) This is pretty darn close to the minimum needed by corals (the compensation point) but it's working for even corals that are generally considered (falsely) 'light-loving.'

They had color, but nowhere near what they have now. My tri color kind of had like a pale pink color to it, and now its bright purple, bright pink

 

[scchase]

Wish I had a par meter back in the early 90s when I had a 55g reef with 2 shoplights, 4 40 watt lamps, never was successful with sps with that setup though. Late 90s I kept a 10g with 2 18 wt NO lamps and had some limited sps success in it.

 

[jwshiver]

Well for the longest time I didn't have access to a Par meter. I have my two Kessil A360WE's over my 40 breeder, and I was scared as hell to burn or bleach my corals. So I never turned the intensity up past 30% When I finally did get a par meter, I found out that nowhere in the tank went over 80 Par. Yet I had SPS corals that were growing (very slowly, but they were growing) Jedi Mind Trick Monti, Reverse Superman Monti, Red Cap monti, Sunset monti, Tri color acro, and strawberry shortcake acro. Since then cranked it up to almost 70% and getting around 250-300 par at my SPS and everything is taking off and growing faster than I ever could have imagined.

How long did it take you to acclimate your corals from 30% to 70%?

 

[Crabs McJones]

How long did it take you to acclimate your corals from 30% to 70%?

I raised it by 10% every week or so ti'll I hit 70%

 

[alton]

Not sure what is the name, I am typically cheap. The first picture is in my 180 that I just fragged from and the Par level is around 80. The second is in my office tank with a Par level of 250. The colony in my office started from a 2" frag 18 months ago. Sometimes quality of light is better than quantity. Both tanks are lit by BML.

 

[revhtree]

This is a great topic!

 

[mcarroll]

Around 10,000 lux from a single array of 3-watt GU10 bulbs that use 30º lenses over a 12" wide tank. Less than 40 watts.

• Bulbs each have three 1-watt emitters.
  • I have cool white bulbs that have three ~6500K white emitters.
  • I have blue bulbs that have three ~450nm emitters.

These are alternated down the row, white then blue all the way to the end.

I also have some "hybrid blue" bulbs where one 455nm emitter has been replaced with one 6500K. The look is slightly better, but they didn't last as long....and they were custom, so >2x more expensive. The regular blues and whites cost $1-$3. Sockets <$1.

Here's where I began considering them when I needed to switch from my old halide system:
LED's to replace a 2 x 150w Radium setup - looking for thoughts!

Note, thread begins in 2012 and ends last year. Post#9 is where I added a note about my current gu10 light. Same original bulbs in a new, much simpler build.

 

[Greybeard]

Don't know, never owned a meter. Had a 40g long with 2x 55w straight pin power compacts, 10k bulbs, that I'd consider very successful, back in the day. Wasn't a cheap light, Corallife, if I remember right. PC aquarium lights were the latest thing, at the time. Grew xenia, colt coral, zoanthids, palythoa, mushrooms, and leathers very, very well. Certainly dim by today's standards.

 

[Dana Riddle]

Not sure what is the name, I am typically cheap. The first picture is in my 180 that I just fragged from and the Par level is around 80. The second is in my office tank with a Par level of 250. The colony in my office started from a 2" frag 18 months ago. Sometimes quality of light is better than quantity. Both tanks are lit by BML.

Sweet!

 

[Dana Riddle]

Not sure what is the name, I am typically cheap. The first picture is in my 180 that I just fragged from and the Par level is around 80. The second is in my office tank with a Par level of 250. The colony in my office started from a 2" frag 18 months ago. Sometimes quality of light is better than quantity. Both tanks are lit by BML.

I've had good success with BML and many experiments we did would have been practically impossible without their lights, but these never looked at minimum lighting requirements but spectral quality instead. BML (Nick and Randy) had to make a business decision about which market they should concentrate their efforts. Naturally, greenhouse lighting is a much larger market than the aquarium side of things.

 

[BoomCorals]

Years ago (in the dark ages, pun intended) we believed intense light was a prerequisite for success with corals, especially SPS. At one point, we actually tested a Fusion sulfur lamp that produced so much light that it maxed out the PAR (measured up to 20,000 micromole/m2/sec.) We know now that corals can grow quite well in low light (if other parameters are in order.) So, what's your lowest PAR that keeps a coral alive (we'll keep growth rates out of the equation for now.) It would be great if you want to mention the lamp type/spectral quality.

I have montiporas and cyphastreas in the far corners of my frag tanks only getting 40-75 PAR. And they grow and grow.

Example:
This mystic sunset montipora frag started as a fresh cut on June 4th. I have kept it in between 40-75 PAR in the far corner of the tank.
From fresh cut, here is how it looked after one month (July 8)

Same frag today, still in low PAR. Though I did switch from SB Reef LED to Kessil LED.

Coloration I think improved (notice the polyps specifically).

edit: looked up the PAR numbers and corrected them

 

[AllSignsPointToFish]

I have montiporas and cyphastreas in the far corners of my frag tanks only getting 40-75 PAR. And they grow and grow.

Example:
This mystic sunset montipora frag started as a fresh cut on June 4th. I have kept it in between 40-75 PAR in the far corner of the tank.
From fresh cut, here is how it looked after one month (July 8)

Same frag today, still in low PAR. Though I did switch from SB Reef LED to Kessil LED.

Coloration I think improved (notice the polyps specifically).

edit: looked up the PAR numbers and corrected them

I run 90-145 PAR and my montipora grow like crazy. I have some acropora, but they seem to struggle a bit.

I run six Kessil A360WEs on 50% intensity max. I've been thinking of increasing the intensity, but I've had the montipora begin to bleach in the past with just minor increases in PAR. I think the acropora would really appreciate more light.

 

[AllSignsPointToFish]

 

[Dana Riddle]

I have montiporas and cyphastreas in the far corners of my frag tanks only getting 40-75 PAR. And they grow and grow.

Example:
This mystic sunset montipora frag started as a fresh cut on June 4th. I have kept it in between 40-75 PAR in the far corner of the tank.
From fresh cut, here is how it looked after one month (July 8)

Same frag today, still in low PAR. Though I did switch from SB Reef LED to Kessil LED.

Coloration I think improved (notice the polyps specifically).

Very interesting. Red fluorescence is generally believed to be found at deeper depths/low light situations. But if blue light excites the fluorescence and, according to prevailing wisdom, transforms it into wavelengths known to promote photosynthesis (and certainly at an efficiency less than 100%), why go to all this trouble? Wouldn't it be advantageous to use the blue light directly? Nice coral BTW!


edit: looked up the PAR numbers and corrected them

 

[Dana Riddle]

I run 90-145 PAR and my montipora grow like crazy. I have some acropora, but they seem to struggle a bit.

I run six Kessil A360WEs on 50% intensity max. I've been thinking of increasing the intensity, but I've had the montipora begin to bleach in the past with just minor increases in PAR. I think the acropora would really appreciate more light.

Great info! Thanks! I need to look at the zooxanthellate clades in Montis and Acros and will comment later.

 

[Dana Riddle]

Around 10,000 lux from a single array of 3-watt GU10 bulbs that use 30º lenses over a 12" wide tank. Less than 40 watts.

• Bulbs each have three 1-watt emitters.
  • I have cool white bulbs that have three ~6500K white emitters.
  • I have blue bulbs that have three ~450nm emitters.

These are alternated down the row, white then blue all the way to the end.

I also have some "hybrid blue" bulbs where one 455nm emitter has been replaced with one 6500K. The look is slightly better, but they didn't last as long....and they were custom, so >2x more expensive. The regular blues and whites cost $1-$3. Sockets <$1.

Here's where I began considering them when I needed to switch from my old halide system:
LED's to replace a 2 x 150w Radium setup - looking for thoughts!

Note, thread begins in 2012 and ends last year. Post#9 is where I added a note about my current gu10 light. Same original bulbs in a new, much simpler build.

Do you think I'm safe in assuming I could use a lux to PAR conversion factor of 50 or 60 to arrive at PAR values of about 170-200? Good info - thanks!

 

[pdiehm]

So I have a reefbreeders Photon 48. I love the 20k look but have been told that my par of like 165 on the rocks with the light at that setting (100 blue, 5 white) is too weak for sps.

So in reading this that is quite possibly wrong?