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

SIRIUS said:
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.
Hope this helps...
Click to expand...

Thanks Cruz.
Most of us have the same par meter.
I have no idea how the SP60 Portable Sphere Spectrophotometer plays into this, but is interesting.
The BiTec Meter is the tool I was curious to see what you used. Based from the list pricing I could find, that's not an option for the hobbyist market :D

The Ocean Optics units (even possibly their MD'd) are still my best option to date. I'm also looking at them as they have fiber optic input. My hope would be that if fiber lenght isn't a limiting factor it could be placed at depth in our tanks. In our homes, we're not looking to perform testign done in isolation from the many variables. We need to know what the corals are actually seeing real word. What a light does in an enclosed testing sphere, as some manuf do, isn't much good for all the reasons in the above posts.
 
I'm wonder about spectrum, because the T world (T12, T8, PC, and now T5) it is readily accepted that there is a duty-cycle and the performance fades over time.

But for LED it seems to be dismissed as "long life" don't worry about it. And somewhat of strange acceptance of "anything in the 400nm range is blue" and "blue is blue".

I feel that is an oversimplification made on purpose because (today) it is difficult to explain or measure.

In the T5 world it is common to hear about "good water parameters" and an algae bloom or fading coral colors to be blamed on old bulbs...time to replace.

What about LED spectrum and fade? It is nice that most now have controller options that let you "mix your spectrum" but it seems black magic like to do it in a way that results in a healthy reef. There are typically defaults for 14k, 18k, 20k but is that reliably getting you what you think or is that just getting a visual hue for the owner?

I'm using a "spread the chaos" approach today (2 different T5 bulbs (coral+ & actinic) and 2 different LED fixtures(AI Hydra & AI Hydra 26)) but its basically a guess.

It would be very helpful to be able to take readings around your tank, before and after adjustment, to determine settings and wear/fade/performance over time.
 
ultimatemj said:
I'm wonder about spectrum, because the T world (T12, T8, PC, and now T5) it is readily accepted that there is a duty-cycle and the performance fades over time.

But for LED it seems to be dismissed as "long life" don't worry about it. And somewhat of strange acceptance of "anything in the 400nm range is blue" and "blue is blue".

I feel that is an oversimplification made on purpose because (today) it is difficult to explain or measure.

In the T5 world it is common to hear about "good water parameters" and an algae bloom or fading coral colors to be blamed on old bulbs...time to replace.

What about LED spectrum and fade? It is nice that most now have controller options that let you "mix your spectrum" but it seems black magic like to do it in a way that results in a healthy reef. There are typically defaults for 14k, 18k, 20k but is that reliably getting you what you think or is that just getting a visual hue for the owner?

I'm using a "spread the chaos" approach today (2 different T5 bulbs (coral+ & actinic) and 2 different LED fixtures(AI Hydra & AI Hydra 26)) but its basically a guess.

It would be very helpful to be able to take readings around your tank, before and after adjustment, to determine settings and wear/fade/performance over time.
Click to expand...

You've hit one of the original reasons for me starting the project several years ago. I'm tired of guessing. All of us are guessing and worse we as a community jump on each new product that comes to market. Thinking, maybe it'll be the product that'll fix the problems we see.

I just don't see enough people getting up in arms about it, enough to change the manuf way of making profits. What's left but to test ourselves, or continue to guess and check with each new light/bulb/other combo?

I do feel all the prebuilt color options in most LED fixtures in the market today are purely to have the tank look as the owner wants it to. It's not about the science of what corals need to thrive. The most obvious reason is why hasn't a single manuf touted this as a selling feature? I mean real science of why their lights are tuned to the spectrum of corals in our tanks.
 
I would hope that LEDs having come from the "digital age" would produce a consistent spectrum regardless of power setting and length of use...
 
Ok, bump this back to the top. I've pretty much decided on buying a meter and which brand.
https://www.alliedscientificpro.com...t-smart-spectrometer-20827?category=14&page=2

I've been talking with the manuf to understand the different models, features and software. I'm thinking the pro essance $1300 model will do everything we need, but I'm still testing with sample software from them. Yes, it's a lot of $$$ but a small fraction compared to what I've spent on this tank to date (or how much I've spent on CR to date! :rofl: ) With lighting as or more important than an other critical factor in growing sps, I'm tired of guessing. I'm building my DIY LED and hoping to get a tunable full spectrum light too. I'd also build a waterproof box for the sensor so it can be used underwater.

So, now that I'm buying a meter, who anyone else as crazy about details as I am?
 
Wow Josh, I don't know how I missed this thread. Good stuff! I would also be very interested in seeing what kind of spectrums are being provided in my tanks.
Following along!
 
Interesting discussion.

Back in the day PFO broke the glass ceiling with only two Cree XR-E LEDs The Cool White and the Royal Blue.

The Cree Cool White provided a nice 450nm Spike along with a wide spectrum excluding <445nm, 470-490nm and >620nm. The extent was greatly dependent upon specific binning.

Only a couple years later Cell Phones became thinner Beards became thicker and we have a wide choice of LED options...The Quality ones offer tunability so one can set the spectrum of their preference.

Personally I like the Old School 400 watt Radium look but have to admit certian corals look better when highlighted with specific colours like 660nm Red and a low to medium amount of 460-600nm...

Just my preference...

For the record I nor my Company is associated with Cruz...

Bill
 
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[MENTION=144]wld1783[/MENTION] and anyone else following.

Finally was able to get all the bugs worked out of the trial software and pulled the trigger this morning. The Essence Pro Meter and Advanced PC software are on their way from Canada. NO MORE GUESSING on the lighting spectrum, with nist calibration trace it's time to see actual results Sanjay stye.
 
jrpark22000 said:
[MENTION=144]wld1783[/MENTION] and anyone else following.

Finally was able to get all the bugs worked out of the trial software and pulled the trigger this morning. The Essence Pro Meter and Advanced PC software are on their way from Canada. NO MORE GUESSING on the lighting spectrum, with nist calibration trace it's time to see actual results Sanjay stye.
Click to expand...

Sweet looking forward to the results

Bill
 
While the advanced software interface sucks, here's a sample output of just a specrtragraph. Green is AI sol blues and the red is the new supplementation lighting I added. For the time being I matched the supplemental light a similar wave form of the AI sols to make sure the coral are happy. I'll then start tweaking the spectrum to include wavelengths seen in natural sunlight.

The graphs are not scaled to each other, their relative output isn't scaled but those are the native outputs in direct comparison. I left in the little UV and higher blue peak on the supplemental light and will watch the coral for a months for negative impact.

View attachment 16921
 
This article brings up an interesting angle to the topic https://reefbuilders.com/2016/08/26/underwater-par-measurement-is-strongly-impacted-by-immersion-effect/
‘When a translucent, diffusing material is submerged in water the change in index of refraction at the boundary of the diffusing material results in a larger percentage of the incident radiant flux being back scattered into the water than would be back scattered into air. This immersion effect is the result of changes in interface reflections, both internal and external, combined with multiple scattering within the diffusing material.’
Click to expand...
 
ultimatemj said:
This article brings up an interesting angle to the topic https://reefbuilders.com/2016/08/26/underwater-par-measurement-is-strongly-impacted-by-immersion-effect/
Click to expand...

I had a very similar worry when I put the spectrometer into the acrylic box. My baseline test was to set the meter on the patio table in full midday sun. Then again in the acrylic box. Overlaying the two graphs, they are essentially one line.

When it comes to submerging the acrylic box with the meter enclosed in it, well I can't. Once the top of the acrylic box is more than 1" below the water level it looses blutooth signal to my phone rendering the sensor useless. What I've setteled on is matching the sun's spectrograph to m lights as much as possible at the surface of the water. Letting whatever happens below the water to happen. While far from perfect, it's the best possible with this setup and a lot better than a par meter alone.
 
So a little update while I'm here. I've added a lot of new spectrum using my DIY supplements and the new fixture. There are several corals that have gone gang busters since doing so. I've also had a large breakout of cyno and the red/brown photosynthetic flatworms. Spectrum was the only change done to the tank, so the likely culprit is the red spectrum addition. I've stopped adding more white end of the spectrum and am waiting to see how it plays out. In the meantime I'm reducing my nutrients significantly with a turf scrubber. Time will tell and I'll post a proper review once I can get a handle on the new problems.
 
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