Blue Par vs White Par

[JAMSOURY]

So I’m new to testing to par, is it normal that par under blue lights test come out significantly lower than under whites?

Just wondering how will I know my blues are strong enough if the par reads low or should I just be looking to aim for overall par with a mix of both of the blues and whites?

 

[James M]

Yes whites are the important ones to coral/anemones and should have a higher PAR reading than blue.

 

[JAMSOURY]

Yes whites are the important ones to coral/anemones and should have a higher PAR reading than blue.

I thought blues were best for growth though. For example, my 2 blue+ only bulbs on a small tank make low par readings.

 

[dantimdad]

Yes whites are the important ones to coral/anemones and should have a higher PAR reading than blue.

OK, not going to argue here but there is way more evidence to the contrary
As a matter of fact, there are those that don't run whites at all and have growth and color. @Lasse please chime in here.

If you look at the absorption graphs, it is in the violet, blue and reds where chlorophyll gets it's energy.

Now, that being said, it is normal for whites to be appear to be brighter.

Violet will spike PAR even though you don't see it as bright.

 

[James M]

OK, not going to argue here but there is way more evidence to the contrary
As a matter of fact, there are those that don't run whites at all and have growth and color. @Lasse please chime in here.

If you look at the absorption graphs, it is in the violet, blue and reds where chlorophyll gets it's energy.

Now, that being said, it is normal for whites to be appear to be brighter.

Violet will spike PAR even though you don't see it as bright.

Learn something new everyday.

 

[Dana Riddle]

I think we should be more interested in PUR (photosynthetically usable radiation.) Here's an analysis of Orphek's LEDs. These were done by measuring PAR and multiplying by the %PUR generated by each. UV and IR are very low (not surprisingly) since a PAR meter doesn't 'see' those wavelengths (but there is some light a PAR meter can measure.)

 

[dantimdad]

I think we should be more interested in PUR (photosynthetically usable radiation.) Here's an analysis of Orphek's LEDs. These were done by measuring PAR and multiplying by the %PUR generated by each. UV and IR are very low (not surprisingly) since a PAR meter doesn't 'see' those wavelengths (but there is some light a PAR meter can measure.)

I was hoping you would chime in.

How was your trip?

 

[Billldg]

I think we should be more interested in PUR (photosynthetically usable radiation.) Here's an analysis of Orphek's LEDs. These were done by measuring PAR and multiplying by the %PUR generated by each. UV and IR are very low (not surprisingly) since a PAR meter doesn't 'see' those wavelengths (but there is some light a PAR meter can measure.)

So my question is should we crank up the blues, purples, and violets, and then steadily turn up the whites, red, and yellow to get the par we want. We keep reading how the coral vendors r keeping their sps tanks at 350 to 500 par which is why I am in the process of switching to a T5/led hybrid.

 

[dantimdad]

So my question is should we crank up the blues, purples, and violets, and they steadily turn up the whites, red, and yellow to get the par we want. We keep reading how the coral vendors r keeping their sps tanks at 350 to 500 par which is why I am in the process of switching to a T5/led hybrid.

I would turn up the whites to get the look you want.

The PUR/PAR should come from UV and blue and reds (Keep in mind that WW and NW have red in them) At least that's my opinion on the matter. @Dana Riddle ?

 

[Dana Riddle]

The trip was great - Tony Vargas was another invited speaker, and we had some time to hang out and visit sites in Piacenza, Milan, and Bergamo. And the food served on Air France was surprisingly good - LOL! As for the Petsfestival, it caters to pets owners of every type - cats, dogs, fish, corals, you name it and it is estimated that 30,000 attend the 2 day event. Made lots of new friends and got some idea of what the reef hobby is in Europe.

 

[dantimdad]

Awesome! Glad to hear it.

 

[Billldg]

I know with the T5/led set up I am putting together I should buy a par meter as I will have more than enough par to cook my frags, just alot of money for very little use. Until then I am trying to find a happy medium with the setup, I will have my xr 15 g4 pros probably at 30 percent intensity and the AB+ program while th T5's are on, the T5's alone will give me roughly 200 par by themselves. Mixed reef tank. I should have Dana come to my house and set it up for me, he only lives 20 or so minutes from my house, LOL!!! Just kidding.

 

[Dana Riddle]

I would turn up the whites to get the look you want.

The PUR/PAR should come from UV and blue and reds (Keep in mind that WW and NW have red in them) At least that's my opinion on the matter. @Dana Riddle ?

There is some evidence that lamps producing about 14000K are best, so , yes, lots of violet-blue with some warmer colors to balance the spectrum out. Too much red, and zoox density/chlorophyll content could be reduced while lots of blue around 450nm is absorbed by protective xanthophylls. I need to research ways of determining xanthophyll content. If successful, the key to the 'best' light for corals could be found... with caveats.

 

[dantimdad]

There is some evidence that lamps producing about 14000K are best, so , yes, lots of violet-blue with some warmer colors to balance the spectrum out. Too much red, and zoox density/chlorophyll content could be reduced while lots of blue around 450nm is absorbed by protective xanthophylls. I need to research ways of determining xanthophyll content. If successful, the key to the 'best' light for corals could be found... with caveats.

Thanks!

I thought that had been sort of a conclusion in another conversation we were involved in, but wanted to make sure. I have slept several times since then.

 

[Ron Reefman]

I think we should be more interested in PUR (photosynthetically usable radiation.) Here's an analysis of Orphek's LEDs. These were done by measuring PAR and multiplying by the %PUR generated by each. UV and IR are very low (not surprisingly) since a PAR meter doesn't 'see' those wavelengths (but there is some light a PAR meter can measure.)

Dana, that's great info, but it brings up a question in my mind.

The graph doesn't show it because UV and IR are not measured by a PAR meter. But, are UV and/or IR valuable to coral zooxanthellae in terms of photosynthesis?

How about to corals for performing other processes like making pigments or other useful nutrients?

 

[dantimdad]

Technically, true UV is dangerous to corals.

Now, Violet in the 420nm area is very beneficial.

IR I have no clue but doubt it's helpful to an extreme.

Dana would know better than I. I just go off anecdotal evidence from testing this stuff out on my own setups. Not very scientific.

 

[dantimdad]

What is going to be interesting is when I have a display refugium setup in a few weeks and start testing the lighting for it and still have a decent "Look" to it.

My fiance' saw the refugium on the nano and said "I sure hope the light on that isn't on the tank you will be able to see" LOL.

The plan is macros, sponges and gorgs with a frog fish.

 

[Dana Riddle]

What is going to be interesting is when I have a display refugium setup in a few weeks and start testing the lighting for it and still have a decent "Look" to it.

My fiance' saw the refugium on the nano and said "I sure hope the light on that isn't on the tank you will be able to see" LOL.

The plan is macros, sponges and gorgs with a frog fish.

LOL. I once spent a great deal of time discussing spectrum and corals with a guy on the internet. I'm talking hours and we finally arrived at a conclusion. He later wrote that his wife made him change the lights because it made the carpet look purple. Lesson learned on my part.

 

[Dana Riddle]

Dana, that's great info, but it brings up a question in my mind.

The graph doesn't show it because UV and IR are not measured by a PAR meter. But, are UV and/or IR valuable to coral zooxanthellae in terms of photosynthesis?

How about to corals for performing other processes like making pigments or other useful nutrients?

Yes, UV-A can be used in photosynthesis. UV down to about 365nm (like that produced by the mercury line spectrum) is of use. Protective mycosporine-like amino acids don't provide protection until around 340nm or so (if my poor memory serves me.) The jury is out on IR - I've been sent data from Germany that suggests IR helps provide protection against UV (yes, you read that right.) I'm skeptical and want to confirm. I've ordered IR and UV bandpass filters. Unfortunately, they're on a slow boat from China. More later.
As for colorful proteins in corals (fluorescent and non-fluorescent) there is evidence that UV-violet light can trigger their production, especially in the Clade D proteins. I really need to get back to work on this. Just need to get a few projects out of the way first.

 

[Dana Riddle]

I know with the T5/led set up I am putting together I should buy a par meter as I will have more than enough par to cook my frags, just alot of money for very little use. Until then I am trying to find a happy medium with the setup, I will have my xr 15 g4 pros probably at 30 percent intensity and the AB+ program while th T5's are on, the T5's alone will give me roughly 200 par by themselves. Mixed reef tank. I should have Dana come to my house and set it up for me, he only lives 20 or so minutes from my house, LOL!!! Just kidding.

Will work for food or corals. Preferably corals.