Know your lights - what is it's spectrum? Who else wants to know?

jrpark22000

jrpark22000

Premium member
Ok, this isn't going to be for most folks. Anyone who knows me, knows overkill and too much knowledge is underrated.

So, here's a good read.
http://www.advancedaquarist.com/2006/6/review

To summarize, many of us have seen the spectral graphs done by Dr Sanjay Joshi, stuff like this (not his work but simplified graph for example)
View attachment 15191

It's the actual radiation measurement of the light source; ex, sun, T5, led, MH, plasma. Not only will each light type but also each bulb or color combination of each will affect the graph.


What's the point to all this? It's been a quest of mine for several years now, but a project on the back burner do to its complexity and lack of tool to measure the end result. Our lights for the most part suck at replicating the sun and corals natural light. Add to that our coral comes from different depths which also affects the speed of the light (water slows light and changes it color.) As a reefing community at large, we have a few lights which we have seen grow coral the best. Most hold 6.5k to 10k halides as the best growing lights out there and why commercial growers use them. Most of us can't deal with the heat of halides, the electricity and the bulb replacements. Given that, the lights we all use are sub-optimal.

We spend crazy money on amino blends, salts, dosing, ULNS and far too many other things. Why isn't anyone putting that much detail into their lights? For one it's difficult. Two, no light manufacturers are focusing on this, instead they are adding random LED colors to their light fixtures because it's what reefers think they need. Or worse, based on what reefers just want, think Iphone and Apple hype.
 
Onto the reason for my thread.

Who else cares or wants to tweak their lights, especially LEDs to be a certain wavelenght?

Let's start an list of those who are interested;

1.ME!
2.
3.
4.
 
I'm contemplating buying such a meter. They're in the $1200 starting range from what I've been able to find in my own research. I have a couple lines out to others who do this beyond a hobby to see their input.

Think community PAR meter program. This isn't something I'd be able to mail to people. It's far to detailed, requires software and is a delicate device. At this point I have gotten any further in the thought process of such a program more than to check interest. I'd likely say we'd be the only ones in the country as a community to go here. I can only hope it'll end up like PAR, the meter costs come down and it's available to everyone. Until then, it takes someone with means and justification to buy one.

As a community organizer I can get around this somewhat. The purchase would still come from my own pocket, not from the forum bank account (I'm not going to affect the giveaway budget for something so few of us would use.) But with the larger community it's not just me looking to use it hopefully. The larger use would help justify the cost.

So who's in to use such a meter? Reply and I'll get you on the list.
 
Further example from Sanjay; Comparison of Sol Blue, 14K ushio and 400W radiums.

See how many of our lights fail across the wider spectrum? Instead of just taking the word of so many manufacturers, let's tell them to shove their marketing and show us the data.

View attachment 15192


Then overlay photosynthesis over these and see where they all fail.

View attachment 15193

and now a simplifed graph showing the sun's radiation seen on earth and how photosynthesis fits with it. The algea in our corals have evolved to grow in it.

View attachment 15194
 
So i read all this and i dont get what u asking lol so this new meter reads different from par like it actually graphs the light source like in the graphs shown or what? I thought i always cared about my lighting and i have a par meter although it never seems to be in my house smh when i need it lol. Ive always swapped bulbs to get right color and still good par but now u saying theres more to it then that dammit wtf smh
 
PAR is by definition is Photosynthetically active radiation. It is a measurement of how any light source matches the Photosynthesis bands show in a graph such as this.

View attachment 15196

There are a couple problems or limitations to a PAR number. First it's a single number. It's generally accepted that AI SOL blues are PAR monsters putting out huge numbers. We can see from the images in the post#4 AI SOL blues are missing a lot of the other spectrums included in photosynthesis. So a high PAR number isn't a full picture of the light as seen by the coral. We need to look at the entire spectrum of the light, taking data points all along the spectrum using a spectrometer. Instead of taking a calculation of the spectrum https://en.wikipedia.org/wiki/Photosynthetically_active_radiation and displaying it as a single number.

To describe it in using a different sense organ, taste. Let’s say we could calculate the taste of an entire food, such a pizza. Create a similar complex formula to PAR but use it to summarize an entire pizza. Then have you taste the single flavor vs you tasting each individual flavor in a mouthful. Trying to express the flavor of an entire pizza in one flavor would surely miss a lot of other flavors. No matter what you do, it’s just not going to taste like a pizza, there aren’t enough flavors.

The same with light. PAR is a portion of the usable light to photosynthesis. Taking more data points (aka flavors) of the given light gives you a better chance to see what it’s actually looks like to the algae in our coral.
 
Dammit now i want pizza sounds cool but still lot of coin plus guessing u would need to be able to change lights dim etc change bulbs and so on am i right
 
madjoe said:
Dammit now i want pizza sounds cool but still lot of coin plus guessing u would need to be able to change lights dim etc change bulbs and so on am i right
Click to expand...

Yep, just had pizza for lunch :D Also correct on you need to be able to adjust your lights in different wavelenghts. With T5 or MH you have to settle with mixing bulbs. Or you can add LED strips to add in colors you are missing.

For my build I'm starting with AI sol blues. Then adding 5 other colors in seperate housings. Each of these colors can be dimmed seperatly and should help get me close as possible with my limted access to LEDs as a end user.
 
Let me also add in some additional research and engineering problems. These are three of which I know of, which there are undoubtedly more.

1. LED dimming. Most people do not run LEDs at their full power. When designed and tested LEDs are given their “nm” spectrum rating when tested at or near full rated power. You can dim LEDs via two driver methods, PWM and CRR. This is the actual method the LED is dimmed by the driver, not how our controllers sends the analog or PWM command format to the driver of what level to dim to. When dimmed via CCR it changes the output spectrum of the LED. When dimming via PWM the spectrum is changed very little. The problem is almost all the drivers on the market today are CCR dimmed.
I ask more about it back in 2013 on RC; http://www.reefcentral.com/forums/showthread.php?t=2165340

2. LED manufacturing. LEDs, especially the cheaper ones, we DIYers have access to are built with a quite large range of acceptable variance in spectral outputs as compared to the actual rating. Getting a 420nm rated LED could get you 390-450nm range or greater. How do you custom tune a LED fixture to a specific output when the components you are using vary this greatly?

3. Wave harmonics. This one Cruz [MENTION=3493]SIRIUS[/MENTION] opened my eyes to. Many of us have experience with audio, in which the waves interact and change each other. Light is just different wavelength radiation, so the same principal applies. By changing one LED spectrum you will affect the others as they interact.

So how you get around all of this?
Measure the actual output of the given light. Adjust each color channel, measuring the output and validating you are getting the spectrum you desire to your corals. Anything else is at best an engineered estimate or at worse, a wild guess.



***edit****
Reviewing the linked thread in RC I rememberd a fourth problem. As LEDs age they color shift. Even if you setup a new fixture correct, as it ages the spectrum will move.
 
A lot of information. I get the basic idea.
I know that MH change spectrum as they age and you said LED do also. So is there a light source that does not?
Also it is apparent that the disruption of the surface of the water causes changes in light intensity, aka glitter lines. Does this also cause spectral change or only intensity? One more wrinkle to figure in. It looks like a pretty complex problem to have a stable spectrum over time.
If nothing else but esthetics , I like the glitter lines and currently only use MH, with no supplementation. This has been the most cost effective solution for the area I need to light, with the look I want. The energy may cost more, but the cost of fixtures to replace the MH , would take a long time to recoup in energy cost.
 
Volcano1 said:
So is there a light source that does not?
Also it is apparent that the disruption of the surface of the water causes changes in light intensity, aka glitter lines. Does this also cause spectral change or only intensity?
If nothing else but esthetics , I like the glitter lines and currently only use MH, with no supplementation. This has been the most cost effective solution for the area I need to light, with the look I want. The energy may cost more, but the cost of fixtures to replace the MH , would take a long time to recoup in energy cost.
Click to expand...

I havn't done the reasearch to know what lights do have spectral changes and which don't.
The surface water movement does casue changes in the light, the larger change from my understanding is the actual depth of the water. As the light passes through more and more water some of the energy is lost to the water. The loss in energy is what causes the spectral shift.
If you can effectively cool the tank and fish room with MH are a good choice for many. When you factor in all the costs; bulbs, ballasts (if ever fail) electricity for running MH and electricity for cooling the tank/fish room due to the excess heat of the MH, it may not take as long to pay off as you think.
 
Cooling hasn't been a big issue. A fan blowing across the surface ,connected to a controller seems to work. My tank is in the basement and the fan blows toward a cold air in take for the A/C. In the winter the MH help heat the tank. I tried going the Kessil route and for my taste , it looked like I would need 3 360WE to replace 1 400 watt Lumenarc large reflector. It would be big up front cost. My other concern was lack of UV light. I choose the Kessils because they were said to be the only LED that gave some UV. I don't have any research to back it up, just grapevine info. I'm sure someday I may be forced to change light sources as MH seem to enjoy less support. Research in plasma lighting may yield another option in the future. It would be nice to find a low energy use product that will cover all the bases. Hopefully tech will come up with something.
 
The wave ripple effects in the water surface creates a convex or concave "lens" platform for any light source... the pulsing of the wave is actually the more natural way that corals receive their light... especially in deeper waters...
I have never been in the ocean scuba diving without seeing beams of lights dancing over the corals...

This is one of the reasons why I have seen better growth and coloration of corals in systems that have larger peaks and valleys in their water surface and a high powered lighting system.... regardless of lighting technology...

There are intermittent intense lines/planes of focused lights in a very sporadic pattern... then a quick refractive dispersion with the ebb of the "water surface lens"...

Is water a lens? Yes... yes it is...

Can we as hobbyists utilize this knowledge to increase depth and penetration of our lighting systems? Yes.... Yes we can...
 
****Edit****by jrpark22000

Sorry no advertising in this thread. Feel free to copy relevant nonproduct specific info.
 
SIRIUS said:
The wave ripple effects in the water surface creates a convex or concave "lens" platform for any light source... the pulsing of the wave is actually the more natural way that corals receive their light... especially in deeper waters...
I have never been in the ocean scuba diving without seeing beams of lights dancing over the corals...
This is one of the reasons why I have seen better growth and coloration of corals in systems that have larger peaks and valleys in their water surface and a high powered lighting system.... regardless of lighting technology...
There are intermittent intense lines/planes of focused lights in a very sporadic pattern... then a quick refractive dispersion with the ebb of the "water surface lens"...
Is water a lens? Yes... yes it is...
Can we as hobbyists utilize this knowledge to increase depth and penetration of our lighting systems? Yes.... Yes we can...
Click to expand...

Can you answer to the phase shift of the light during this effect? Does it affect phase during these short bursts of the lens as they travel across the subsurface?

I can only use my par measuring experience as a guide. With surface distortion, PAR does have some variance but it's relatively small and we’d expect in the ocean as well. Of course it’d depend on the wave conditions. While many of us shoot for the shimmer affect in our tanks, isn’t it more reasonable to tune a light source spectrum to stay in line with what the sun is at the surface of the water? In the wild the water conditions are going to vary from hour to hour, day to day. Trying to mimic an average of these conditions, as our tanks have a much more stable water surface condition, in my thoughts would be more practical. Even without lensing, phase shift caused by depth would still be worth wild to measure. I’ve seen little to no scientific data on the measured phase at depth, typically just anecdotal info or observations. Even without lensing, accounting for any phase shift at depth could be likely too complex to factor given our corals different depths in the wild. Actual measurements would correct any theories. I’m thinking the most likely method to account for depth would be based the depth of the tank measured and the typical water depth of the wild coral in question. Then shift the entire spectrum red as our tanks are on average shallower. The amount is the $1million question. How to average the depth of these different corals could end up a quite muddy solution and suboptimal.

That is one of my far off goals, a more reasonable short term goal is to obtain measurement tool(s). There are cheaper (Manufacturer Discontinued) alternatives but they are far less portable.
 
SIRIUS said:
****Edit****by jrpark22000

Sorry no advertising in this thread. Feel free to copy relevant nonproduct specific info.
Click to expand...

Apologies!!! There was just a lot of information on there regarding PAR, spread, real life intensities... :) But I will refrain...

Sorries!
 
JR, We utilize three different instruments.... actually four (the fourth is a 3rd party tester) at SIRIUS tm...
One is the PAR meter, the MQ-200 Quantum Separate Sensor with Handheld PAR Meter (what most people use in the hobby so we can correlate with hobbyists)
Second is a light meter, the BTS2048-VL BiTec Sensor Light Meter (Gigahertz-Optik) for most of our in house testing
Third is a sphere spectrometer (portable) SP60 Portable Sphere Spectrophotometer (which is no longer being manufactured but blocks out all other external light sources)
Fourth is a 3rd party lighting lab that tests the intensity and the spectral composition of the light source (or blend) for 3rd party certification results that is objective, not subjective.

Most LED companies in our hobby today do not even test... FYI

Hope this helps...
 
What we as hobbyists have to take into consideration is that dynamic water (moving and pulsing like in nature) produces both reflective and refractive planes...
Still undisturbed water is bad to know exactly what the penetration of a certain PAR or Intensity you are actually measuring...

I have seen many people wonder why their corals are not coloring up or not growing... they read 300PAR at the coral (but with the return pump and wave makers off)

Intensity and duration of intensity is key in understanding the requirements of our glass caged reef inhabitants...
 
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