Open letter to the LED industry

[Pacific Sun RD]

I would tap dat!

It's Brett's 850l SPS tank:
http://www.masa.asn.au/phpBB3/viewtopic.php?f=145&t=239341

TOTM award October 2013:
http://www.masa.asn.au/phpBB3/viewtopic.php?f=51&t=254449

 

[Reefer54]

I have posted the following on two other threads, but i think it may benefit here, if it has not already been posted. And it may have....I couldnt read 17 pages tonight. sorry for any redundancy.

I have read that LED Par needs to be 30-40% less than MH. I asked the longtime poster where the info for those numbers came from, source or experience......no answer.

So my question is if there is merit to the 30% decrease in Par value to essentially acheive the same amount of Par.....anybody, please enlighten with sources or experience, preferably both.

I read all too often of people scorching corals under super intense leds running 100%, and also that reducing the Led's from 50% to 70% power seems to be the norm for optimal par and the reaction of great coral color and growth.....I believe some info in regards to this may really benefit some.

I run (2) 165w custom full spectrum Leds on a 75g with a 7in DSB. Whites (red, green, yellow, and orange too) are run at 80% and Blues at 95%. 1 light hangs 6 in over the water, the other hangs 10" over the water.....15" to sand bed. Keeping LPS, SPS, Palys, and a clam. I did not light acclimate very long and did lose some color on SPS, browned a couple of LPS and have over time regained the color lost with the sps (though not to my liking yet) and slowly have started regaining the color browned with LPS (they are slower to adapt it seems so far). I have documented this from start to finish and will post progress at a year. In the meantime i continue to research and research, it just seems there are no good answers, just good word of mouth.....as is our hobby to some extent.

thanks and i hope i help someone.

 

[Reefer54]

Oh, my par meter reads 412 for a high at the surface, and a low of 89 on the sand bed...and of course everything in between depending on where.

 

[hypnoj]

I think it will be important for you to read the first 17 pages to get your answer.

 

[Ron Reefman]

It's just a personal opinion, based on my understanding of science.

The PAR from a MH and the Par from and LED or any other source is the same. It's a measurement of light photons hitting the surface of the sensor. The sensor doesn't care (or know) what source created the light.

Now the common PAR meter used is probably the Apogee and it reads a bit low in the 400nm spectrum and ramps up as the wavelength gets longer. And it also falls off a cliff at the other end of the spectrum, about 670nm and up. Does that make any difference to what your light sours is? I don't think so, but I'd be willing to hear arguments to the contrary.

 

[Pacific Sun RD]

PAR measured under blue leds can be 9in real) even 50% higher than on your quantum menter.
Why?
That chart explain everything:

For Royal Blue leds(which have dominant light wave at 445nm) quantum meter will show even 25% lower numbers.
If your lamp will use several violet leds also(with peak at 420-425nm) - real number for them will be even 50% higher).
So - real % "correction" for your lamp depend from:
- type of used leds
- their number and real output power(depends from current)
Even for cool white leds(which have also big "peak" at ca. 450nm - real number are up to 10% higher than measured under handy quantum meter(like Apogee).

 

[Lurking]

I want all the LED companies involved in a thread like this. !

It doesn't happen because as already evidenced in this thread, there are way to many who just troll and pick fights and want to be argumentative. It sucks but many company's in this industry have a policy forbidding forum use for this reason.

 

[nynick]

It doesn't happen because as already evidenced in this thread, there are way to many who just troll and pick fights and want to be argumentative. It sucks but many company's in this industry have a policy forbidding forum use for this reason.

...and according to that theory on forum debate degeneration it is only a matter of time before someone states that something is Hitler's favorite LED.

 

[Vannpytt]

It doesn't happen because as already evidenced in this thread, there are way to many who just troll and pick fights and want to be argumentative. It sucks but many company's in this industry have a policy forbidding forum use for this reason.

I can't really see anyone trolling with the information/facts that PS provided in this thread. Basically, if he's right, the others are wrong. Not saying the other lamps don't work, they are just not optimal.

 

[Big E]

The new Apogee 200 is accurate enough for hobbyist purposes when measuring White and Blue diodes.......it needs to be set on the "Sun" mode.

 

[Reefer54]

I think it will be important for you to read the first 17 pages to get your answer.

so clearly you dont know...or you could have said something constructive, like, its on page 4.

Thanks for all the input to everyone else, all 18 pages were a great read, and i gained a lot and I am sure i will revisit it often.

 

[Pacific Sun RD]

The new Apogee 200 is accurate enough for hobbyist purposes when measuring White and Blue diodes.......it needs to be set on the "Sun" mode.

Not exactly...
For example - measuring Royal Blue leds(cree) with peak at 445nm - reading error can be even 25%.
For "deeper" light like violet - with peak 420-425nm - mistake can reach even 50-60%!
Only using proferssional spectrum meters together with quantum meter you can read REAL PAR for led lamp..
Take a look for that chart:

 

[Big E]

That's not what I said..................I said the white and blues set at "sun" are quite accurate compared to the high end Li-Cor which is a high end meter and very accurate for our purposes.

The Apogee 200 unit will work fine for any hobbyist that is setting up the lights for their tank. The most important thing is consistent numbers anyways. Even being off 20% on certain minor LED colors is meaningless when setting any light for settings, height ect. for corals.

What most important is a minimum/maximim range of par to grow & and get good color.

There is no need to over analyze the numbers.......the corals don't react to small percentage differences. The Apogee 200 is a fine meter that has worked well for what was needed in LED setups in my experience.

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[rog2961]

Read this thread quite a bit in the beginning then trailed off as it got bigger. From what I've read, it would be wise to swap out some of the white leds in my d120 for a couple blue(better) and some royalblues? Would it be wise to replace the few reds with a couple blues as well?

 

[zachts]

On a previously mentioned note about the industry not making white LEDs just for the hobby, seems ORPHEK has two different violet based white LEDs in their fixtures.....

It's a start anyway.

 

[claudacate]

If that full spectrum would be responsible for strong corals pigmentation and growth - most beautiful corals should growth directly under water surface - up to 1-1.5m - but they arent.
Corals on shallow waters are mostly brown, cream(hard corals). They have many symbiotic algae and only two-three species colorfull which can be find in shallow water is Pocillopora sp.(verucosa, damicornis and meandrina) and
We did several measurments in Bali two years ago(on different deep - spectrum and PAR readings) and few Bali farms - when corals was placed in shallow water - growth was very fast(but colors - washed), for pigment activation(stronger colours before shipments) - they was putted to deeper stands - up to 5-10m(the same species).
Growth was slow, but color was very, very nice..
You have to agree, that on 10m deep there is less light than under surface - and some of wave are missing.
The same corals taken from 10m to "better" light condition (shallow water with "full spectrum" light) go to brown/bleach and loose pigments.
Similar we can see in our tanks - when we will not acclimatize corals to new, strong light.

I have a question when I read this part. If the spectrum reaches deep water is around 420nm to 500nm and it promotes good colors but slow growth, what spectrum is responsible for symbiotic algae and the subsequent coral growth?

 

[biom]

Hi ;-)
Its much more difficult than you think.
Light spectrum build by T5 bulbs depend from used gasses and and phosphor layers - newest T5 bulbs used Tri-phosphor coating(like ATI Purple Plus or KZ Fiji Purple - its almost the same bulbs - like ATI Aquablue and AquaMedic Blue Plus)... We have measured them all - and compared together..

I thought Fiji is far more different than ATI Purple. Very interesting thread, Subscribed.

 

[wayne in norway]

All that stuff about underreading blue light is equally valid for 20K MH and especially blue t5 tubes. I remember the table for PAR from various T5 tubes, and it makes you wonder we underestimated the power of the various narva blues.

 

[Pacific Sun RD]

I thought Fiji is far more different than ATI Purple. Very interesting thread, Subscribed.

They are different - but not so much(in spectral chart).
Here you can find comparision to another one, Pigment INT+
Its a "middle" tube - between KZ and ATI.

 

[rtparty]

All that stuff about underreading blue light is equally valid for 20K MH and especially blue t5 tubes. I remember the table for PAR from various T5 tubes, and it makes you wonder we underestimated the power of the various narva blues.

Not exactly.

Most 20k halides have less total blue than 6500-10k halide bulbs. There was a great Advanced Aquarist article all about it. Wish I had the link with me.

The 20k bulbs have less red, yellow and green to make the appearance more blue. So the 20k halides registered slightly lower on standard PAR meters but not enough to bother.

The ATI blue plus only registered like 7-10% lower than actual value because there is still a nice green peak to them. Again, not enough to truly worry about.