6500k T5 Bulbs - Important Spectrums Missing in LEDs?

[oreo54]

Interesting - normal LED PWM works above 2000 Hz (2kHz) and T5 tubes has a frequency of around 40 000 kHz

Sincerely Lasse

for which drivers? Most Meanwells and Aduino based controllers create outputs in the 500Hz range...Couple of O-scope traces out there showing output.
BOTH PWM signal and drive voltage signal. Need to keep the 2 things separate..
Like just because one uses 0-10v dimming does not mean output is NOT pulsed..
No idea about what most "commercial" units use..Now switching Power supply frequencies are that high..AFAICT

PWM fans and motors push those high frequencies as well..

going back a bit.. phosphor latency (and other electrical voodoo) in T5's could smear the off time.. really never going "truly off" per-se..
LED's def are different in that area..well other than whites or phosphor converted types..

From what I remembered LED monochromatic diodes can turn on and of at VERY high rates and very errr.. sharp cutoff..picoseconds..

Just stuff to think about..

Direct emission LEDs typically have a turn-on time in single-digit nanoseconds, longer for bigger LEDs. Turn-off times for these are in the tens of nanoseconds, a bit slower than turn-on. IR LEDs typically show the fastest transition times, for reasons given ahead.

Special purpose LEDs are available, whose junction and bond-wire geometries are designed specifically to permit 800 picosecond to 2 nanosecond pulses. For even shorter pulses, special purpose laser diodes, in many ways operationally similar to LEDs, work all the way down to 50 picosecond pulses.

As pointed out by @ConnorWolf in comments, there also exist a family of LED products with specialized optical beam shaping, that boast pulse widths of 500 to 1000 picoseconds.

Phosphor type LEDs have turn-on and turn-off times in the tens to hundreds of nanoseconds, appreciably slower than direct emission LEDs.

 

[Lasse]

@oreo5457 Can we please get back to the OP. Please - if you want to keep on with PWM - start your own thread about it

Sincerely Lasse

 

[oreo54]

One last thing - the use of PWM dimming. The photosyntetic process is by natur a quantum mechanical process - it means that it act in a digital maner - on/off with a frequency. The wet dream would be to find this frequency and send out photons of the right wavelengths and with the right frequency in order to optimize this. The problem, however - what is the frequency and how stable is it? What´s happen if the frequency is wrong? Some commercial producers of LED fixtures for green houses do only use PWM for the first 10 % and after that 1-10 V signal to manage the current. Are there any biological reasons for that? I do not know and probably will not ever know - but since I realized this - I run at 100 % or limit the current. Just ramp up and let it be there.

"I" didn't bring it up in the first place.. but sure..
But bringing it up added a piece to my understanding/pondering of LED"differences" so much appreciated..
Carry on...

cyan, cool blue, violet, are lacking or missing in common 6500k Led's and needs more red..
Only 6500k LEd worth anything , without "building" the spectrum w RGB is Luxeon fresh fish and sunplus.
CREE does make some but are harder than hens teeth to find..
You can build almost any light pattern emitted by t5's or MH's using LEDs.
unfortunately manuf. could care less atm..

currently I believe there are no "magic" photons emitted by any particular light source.

 

[Phelipe's Ocean]

I am not saying that I am right. I do not even care if I am right. I am just saying that there is evidence that should be considered at and not discounted... Radion at 80% burns coral, but at 100% does not? RB Photon definitely burns coral with too high of percentages, but at 100% also appears to be better/OK (I cannot confirm this like with Radions). Coincidence, maybe... but maybe not. I think that it is worth looking into.

I am sticking around for when the implementation gets good. I do not care to be a guinea pig with my tank right now. I am losing faith that it ever will get good since it has been 10-15 years and there is still a long way to go. I have not really seen a real innovation since panels changed from just blue and white to multicolored. I am ready for the next disruptive advancement.

I totally agree with this, there is still a long way to go in regards to technology advancements with LED’s and I will not be switching out any of my halides or T5’s to experiment with the latest and greatest LED. The day the lighting debate is over is the day I will know LED’s got it down. People that say LED’s perform the same as halides and T5’s there I have a very simple answer for them. If that was true there would not be a lighting debate anymore. If you could get the same results why would anyone deal with heat and bulb switches? Exactly...

 

[Velcro]

I totally agree with this, there is still a long way to go in regards to technology advancements with LED’s and I will not be switching out any of my halides or T5’s to experiment with the latest and greatest LED. The day the lighting debate is over is the day I will know LED’s got it down. People that say LED’s perform the same as halides and T5’s there I have a very simple answer for them. If that was true there would not be a lighting debate anymore. If you could get the same results why would anyone deal with heat and bulb switches? Exactly...

Maybe they are using lighting as a scapegoat for system instability.

 

[Norcalreef]

I didn’t want to get involved but man it’s is just insane how @jda has to turn every single lighting thread into a mh is better than led battle. My other passion is growing medical. No one and I mean NO ONE use MH. They are incredibly inefficient dinosaur way of lighting. I was truly shocked to still see people using them when I started this hobby. Oh and that UV and other “goodies” most people claim MH has is blocked by the jacketing. Most reef leds are not designed well. It’s not the fault of the leds but the companies designing the fixtures.
I have all but stopped reading the lighting section because of this nonsense. This thread was about 6500k not mh being better than led. The ego of some on here is pretty pitiful

 

[Velcro]

I didn’t want to get involved but man it’s is just insane how @jda has to turn every single lighting thread into a mh is better than led battle. My other passion is growing medical. No one and I mean NO ONE use MH. They are incredibly inefficient dinosaur way of lighting. I was truly shocked to still see people using them when I started this hobby. Oh and that UV and other “goodies” most people claim MH has is blocked by the jacketing. Most reef leds are not designed well. It’s not the fault of the leds but the companies designing the fixtures.
I have all but stopped reading the lighting section because of this nonsense. This thread was about 6500k not mh being better than led. The ego of some on here is pretty pitiful

I don't think the jacket of the SE bulbs nor the glass shield for DE bulbs blocks all UV. Just blocks UV-B right? Maybe I'm mistaken.

 

[madweazl]

I don't think the jacket of the SE bulbs nor the glass shield for DE bulbs blocks all UV. Just blocks UV-B right? Maybe I'm mistaken.

That is correct; UV-A is approx 400-320nm and UV-B is 320-290nm. Looking at the measured spectrum of MH (along with T5s and some LEDs), there are certainly wavelengths being emitted well below 400.

 

[Lasse]

The graphs below show the amount of photons in micromole per second and square meter at different wavelengths at different deeps for a 1000 W Reeflux MH

Surface

​

30 cm - notis the loss of wavelengths > 800 nm. It is IR (Heat) transmitted to the water already at 30 cm

​

60 cm depth - most of the heat are transmitted

​

90 cm depths All heat transmitted

​

Interesting is also to see that there is a small amount of UV A going down but at 60 cm - wavelengths below 390 nm appear to disappear.

Sincerely Lasse

 

[Phelipe's Ocean]

Maybe they are using lighting as a scapegoat for system instability.

Interesting then I guess our water just decides to become stable when we put haides over it.

 

[jda]

The glass bulb for SE removes the super harmful UV below 350nm - you do not need any glass shield to use SE bulbs. This does not happen with a DE bulb, which is why you need the glass shield on the fixture or you can damage your fish, corals and even algae. Both allow a good amount of UV from 350 to 400nm. Not only does T5 and MH emit this spectrum, so does sunlight on the reef... I guess that the water on the reef becomes stable when the sun illuminates it too. UV penetrates in good numbers down to about 10 meters on the reef.

 

[Velcro]

Interesting then I guess our water just decides to become stable when we put haides over it.

How many tanks have you personally seen where someone went from LED to halide with no other changes and suddenly everything got better? Better yet, how many of those situations were there that the LEDs were adjusted by PAR and had truly enough coverage of fixtures, yet they still weren't having success? Exactly....

 

[tsav87]

PAR numbers tell you nothing unless you have spectral date along side it. You can have PAR and 150-300 and not be able to grow coral if the spectrum isn't right.

I think that is the disconnect between LED and MH / T5s. I'd would guess that 99% of hobbyists have no idea what spectrum their LEDs are putting out.

MH/T5 is easy, it just works, no setting to tweak. I think that is why the success and failure gap is so wide with LED users. For most LED fixtures, the user is flying blind when it comes to spectrum.

 

[Velcro]

PAR numbers tell you nothing unless you have spectral date along side it. You can have PAR and 150-300 and not be able to grow coral if the spectrum isn't right.

I think that is the disconnect between LED and MH / T5s. I'd would guess that 99% of hobbyists have no idea what spectrum their LEDs are putting out.

MH/T5 is easy, it just works, no setting to tweak. I think that is why the success and failure gap is so wide with LED users. For most LED fixtures, the user is flying blind when it comes to spectrum.

Okay.... but let's look at the most common fixture. A radion with SPS AB+ setting. The spectrum is known and the only variable is intensity. Par is going to be very useful in 99% of LED applications in the hobby... Sure you can crank reds and greens and falsely inflate PAR, but that just isn't going to happen most the time. Even if you crank the whites it's mostly blue.

 

[Sallstrom]

If metal halide better then a new LED fixture, then how can we test it? What makes it better? Should we meassure growth in weight and compare? How to compare lamps, in watt or in PAR? Compare covarage? Compare spectra?

It's fine to like this or that better, but with no arguments more than "this is better..", this thread is not getting anywere..

So do they need wavelenghts over 750 nm or below 400 nm to grow? Or to grow better? Or to reproduce? Or are those wavelenghts wasted on corals?

 

[tsav87]

Okay.... but let's look at the most common fixture. A radion with SPS AB+ setting. The spectrum is known and the only variable is intensity. Par is going to be very useful in 99% of LED applications in the hobby... Sure you can crank reds and greens and falsely inflate PAR, but that just isn't going to happen most the time. Even if you crank the whites it's mostly blue.

The manufacturer of that unit did the hobbyist a service by creating a spetrum favorable for coral health and growth. That hasn’t always been the case with many LED fixtures.

 

[jda]

Crabs just did... saw tremendous improvement from adding T5s... got to thinking that if the T5s alone made all of this difference, then why not go even further. 250w Halide with T5s for him now.

Schnitzel is another one, but with ATI T5s.

Tom (Tdb320) was another one.

There are three just off the top of my head, not to mention the ones in the threads where people ask these questions.

Think of the successes of adding T5s to LED (which are many) as step one in a three-step program that more and more are taking to the finish line.

These stories are all over the place if you actually want to hear. Rather than listen to the hobbyist, some can also make excuses that it was water, "using the LED wrong," husbandry and otherwise explain it away.

If it is that easy to just use AB+ or Kessil with "known good spectrum," then why all the talk about using LED wrong? Can it both be that easy and that hard? (I do understand that people screw with their fixtures too much)

 

[jda]

If metal halide better then a new LED fixture, then how can we test it? What makes it better? Should we meassure growth in weight and compare? How to compare lamps, in watt or in PAR? Compare covarage? Compare spectra?

It's fine to like this or that better, but with no arguments more than "this is better..", this thread is not getting anywere..

So do they need wavelenghts over 750 nm or below 400 nm to grow? Or to grow better? Or to reproduce? Or are those wavelenghts wasted on corals?

Growth weight is not enough, but it is a start. The old standby is that "LED can grow coral just fine" which is true... but also only part of the picture. Where this will always be hard is that you need the eye-test as well. There will always be people who will want to see a tank like Copps under LED... or Steve Weast... or some of the many others that are real masters (not just masters in ReefBuilders articles). There are some good ones, but none that get to where these people are.

Do you see benefit from 700-750nm, or was that a typo? I also believe that there is benefit in IR, so I am curious. I like light from 350-800nm, personally.

All that I know is that the best of the best tanks, and the ocean, use lights (MH and T5) that have these wavelengths. Coincidence... probably not. I would rather be like those people than the ones that do not. If you want to argue that most people have never been at this level and will never get to this level, then cool, I will not argue with that... but I can, so I do not limit myself.

 

[tsav87]

Really, the whole thing about it is that we are human. If we can bump up an LED channel that MIGHT increase growth, you know we are going to try. That sort of thinking is good for progress but not good for the coral. How long do you stunt growth while the coral tries to readjust to the new spectrum? Hobbyists get impatient, then make another adjustment, then another, and so on. The success from MH and T5 comes from the lack of fine adjustment that can be done by LED. The net result is a steady, stable light source. It's human proof lighting.

 

[oreo54]

Crabs just did... saw tremendous improvement from adding T5s... got to thinking that if the T5s alone made all of this difference, then why not go even further. 250w Halide with T5s for him now.

Schnitzel is another one, but with ATI T5s.

Tom (Tdb320) was another one.

There are three just off the top of my head, not to mention the ones in the threads where people ask these questions.

Think of the successes of adding T5s to LED (which are many) as step one in a three-step program that more and more are taking to the finish line.

These stories are all over the place if you actually want to hear. Rather than listen to the hobbyist, some can also make excuses that it was water, "using the LED wrong," husbandry and otherwise explain it away.

If it is that easy to just use AB+ or Kessil with "known good spectrum," then why all the talk about using LED wrong? Can it both be that easy and that hard? (I do understand that people screw with their fixtures too much)

you can't determine anything without quantifying what went from what to what..
I'm not completely adverse to your opinion but again.. say replacing 2 Kessil 360's w/ a 450W MH and getting better growth?
NO surprise considering the added photons..REGARDLESS of spectrum.
Same w/ say adding an 8 tube t5 (432W) vs 2 or 3 Kessils ect (270W)..

Adding t5's to an LED array and more growth again, NO surprise considering you are adding more photons..
Adding some Orphek strips might have done exactly the same thing.

Devil is ALWAYS in the details..

I guess some like things idiot proofed, others like a challenge..