Why all the talk about LUX?

[saltyfilmfolks]

A. The apps dont use the camera. They use the light sensor that the software then uses for the camera ISO auto adjustment.

B. "The olden days"is also a time period when almost all reef aquarists were using similar bulbs, either incandecent or hallide 6500K lighting so saying 3000 lux at the sandbed was an easily comparable statement tabk to tank. Todays technology simply makes LUX and nearly useless measurement as even fixture to fixture some quality defects, tank particulate, even salt concentration can effect LUX levels. Let alone as previously stated many times, the simple lower end of spectrum where lux diminishes and PAR/PUR rockets upward in measureable values.

You should read that article. They list different bulbs. Par has the same problem with diffusion there an apogee formula now addressing it. The two half way decent lux apps use the camera. It says so.

 

[saltyfilmfolks]

I use several cheap luxmeters myselft as substitute for PAR measurements but only in my greenhouse and on my window sills. Natural daylight has always an even and similar spektrum. But you just can´t compare a Royal Blue LED with a white LED using a luxmeter except you have an exact conversion factor for both. But even then I would doubt that a cheap luxmeter follows the norm lux response curve precise enough that you have meaningful numbers in the end.
For aquaria and artificial lighting I prefer the PAR measurement, for example with a Apogee PAR meter.

I would prefer a par meter too.
But if you start blind with a mars Aqua on a 24 in deep tank setting the intensity to 20000 lux is pretty safe advice no matter the conversion factor. Then move up from there. Keep an eye on the coral as you increase intensity. There's also user par lux data available on the mars Aqua.

Natural daylight actuall changes through the day and and changes greatly when indirect. Depending where you are in the world you can get 60000 lux from just sky.
No direct sun. That's usually Aron's 20kelvim maybe littl less But depending what your growing. It prob fine. Some plants don't like 65k. Arboreal orchids and othe shade plants.

 

[chema]

It's in a different article by the same author.

Please, could you point me out to that article?

 

[Hans-Werner]

I think luxmeters cannot be applicated to compare different LEDs and they have their limitations when the light has lots of blue or violett. To get a good estimation you should have the spectrum of the lighting in addition to see whether there is a large proportion of PAR that is underrated by the luxmeter.

 

[Hans-Werner]

... sorry, luxmeters cannot be applied ...

 

[madweazl]

Reading the posts, the one thing that keeps being ignored is the ability to compare similar lights with measured results. I see no mention of users measuring a Radeon with blues at 100% with no red to one with 100% red and no blue. If we measure a Radeon with 100% and 5% red with a LUX meter and get 50 LUX (arbitrary number), the next Radeon running the same configuration will be roughly 50 LUX. If this same configuration was also measured with a PAR meter at some point, you have a correction factor that should remain relatively constant at those settings. If you then create a database with this information (similar to what was linked to in an earlier post), somebody can go out and purchase light X, set it X inches off the water, with XXXXXX spectrum and shoot for X LUX with a pretty good idea of what the PAR would be (far better than no idea what-so-ever).

 

[gus6464]

You can get one that goes in the aquarium if your curious. Or put it in a ziplock bag or get one designed to go in the ocean. They make those.


Most people who use any light meter of any type are surprised at how rabpidly light fields change any where at any time of day Fromm room to room. From fixture to fixture too depending on the design.
You should actually try it.
I have for 25 years. In snow water rain swimming pools forests stages deserts city's buildings slums and aquariums.

He also says the lux meter is ok as it's cheaper but not as accurate in many ways and has limitations like all of us lux meter users also say. And have from the beginning of this thread.

I find see where he said it was usless.

You won't give an inch because you don't know anything else.
We all understand a par meter.
Your camp clearly does not understand light meters.
You definitely do understand not having access to one.

None here have come forward with a better way at to teach and understand how to explain how to set a light on a tank without guessing besides getting something they can't afford or find or borrow.
We have. It is not ideal. It is not entirely accurate. But it works.

That is an article by an actual expert who says it works but has limitations that we all accept and also explain that same thing to people on a daily basis but you won't set aside Whatever your issues are to accept th scientific fact.

In a forum so accepting of any and all types of reefing from canisters to aquaclears I find it mind blowing the dissent and near ridicule in this thread to the use of a simple tool to educate people on how light works.
Intensity. Spectrum.

You are welcome to believe that a difference in 14 par wilnkill your coral and I will gladly
Let you run your tank that way. People chase ph and everybody say not to so you can chase yours. How about you let us chase ours. I can use an API test kit if I want to. If I get the full salifert one day great. Right now it's what we got.

I'm sure there's a problem with salifert too if I post a thread on it.

Ok actual ridicule. That's still got me pretty steamed. It not what we see here or do or how we behave here. So a discussion about meters devolves into this?
Well done sirs Well done.

All of those Dana Riddle articles are insanely old and don't pass any muster today unless you have actual conversion factors for modern LEDs. I have yet to see any post from you posting the conversion factors for any of today's most popular modern light units. You keep quoting his articles and he clearly states that a different conversion factor is required for every single light source as the spectrum is different. So once again, where are your conversion factors with your recommended lux numbers?

Let's take just one single example from the chart. Ushio 10K and Coralife 10K. Both 10K bulbs. Conversion factors could not be any more different. 54 vs 30 is almost 2:1. You tell both guys they want around 40000 lux. Ushio guy will be pushing 740 PAR while Coralife guy will have 1333 PAR. You don't see anything wrong with that?

That scenario above is even worse with modern LED fixtures where people can switch the spectrum with the push of a button to something completely different than what they had 5 seconds before. Now you are being petty is saying that the difference is 14 PAR when in reality the difference can be huge.

 

[gus6464]

Reading the posts, the one thing that keeps being ignored is the ability to compare similar lights with measured results. I see no mention of users measuring a Radeon with blues at 100% with no red to one with 100% red and no blue. If we measure a Radeon with 100% and 5% red with a LUX meter and get 50 LUX (arbitrary number), the next Radeon running the same configuration will be roughly 50 LUX. If this same configuration was also measured with a PAR meter at some point, you have a correction factor that should remain relatively constant at those settings. If you then create a database with this information (similar to what was linked to in an earlier post), somebody can go out and purchase light X, set it X inches off the water, with XXXXXX spectrum and shoot for X LUX with a pretty good idea of what the PAR would be (far better than no idea what-so-ever).

That's totally fine but do you see any of the people telling others to use LUX meters posting these conversion factors? I just always see random lux numbers and that's it.

 

[saltyfilmfolks]

I think luxmeters cannot be applicated to compare different LEDs and they have their limitations when the light has lots of blue or violett. To get a good estimation you should have the spectrum of the lighting in addition to see whether there is a large proportion of PAR that is underrated by the luxmeter.

Yes it is underrated for those spectrums. Read mr riddles article. He explains this. He also still uses the Lux meter.
Incedently (lighting joke there) he collects par meters because he likes them. Still says lux meters are ok and he is an actual scientist.
Again a lux meter will give you a close approximation or estimate. Is you want a more true par reading get a par meter.
Get a good one thoug because they are not all as accurate.

 

[Daniel@R2R Verified Admin]

I think at this point I have the answer to my question. Basically, the use of LUX should be helpful in determining relative light levels in the same way the human eye does, but it's more precise. This is useful when you already know you need to raise or lower a level (assuming you're keeping the same spectrum) as it provides a more precise measurement than the human eye. However, it is not useful in determining levels needed for corals if moving from one light source to another since spectrums are going to be different which will change PAR/PUR levels. Conversion factors can help, particularly with MH or T5 bulbs, but with LED's, the variables are too much to really speculate PAR based on LUX.

Takeaways are...

1) LUX is better than the naked eye (so if you're not going to use a PAR meter, LUX is better than nothing).
2) Without understanding the difference between LUX and PAR or how corals use light, trying to use LUX could actually be detrimental to your livestock (as it can give a false sense of security if misunderstood).
3) PAR is definitely a superior measurement for reef tanks, but LUX meters are an affordable substitute if used as a "better than nothing" solution with recognition that they are inferior to PAR meters.
4) Using any blanket statements about your corals will do best under X amount of LUX is a bad idea because of variations of PAR under the same amount of LUX.

Is that a fair summary?

 

[saltyfilmfolks]

Please, could you point me out to that article?

Yes here it is.
Interestingly his conversion numbers are very low. numbers

I was going to ask Dana about this at macna but dr Craig Bingman cut me off and I wound up standing there with them learning more about light flow and alkalinity uptake than any poor reefer deserves.
Yes y'all. I shouldn't have bought a par meter instead I spent it on three days in a room with scientists

 

[saltyfilmfolks]

That's totally fine but do you see any of the people telling others to use LUX meters posting these conversion factors? I just always see random lux numbers and that's it.

Lux has been so downplayed in reefing its become forgotten. It's not cool it's not fancy and it's not expensive. Led with the insanely controllable color combinations for really no purpose to most is very hard to do as the variables are so extreme.
I'm also fairly certain If you did do Lux par conversions at full intensity on the best leds it would show that they are not nearly as good as a mh or t5.
I'm absolutely dying to see it done on a Radion. Not that it would put me off buying one. Because again if it has the correct spectrum it may need more intensity to deliver it.
The seneye has a Lux function but I've seen a couple of user tests that make absolutely no sense whatsoever compared to the PAR of a mh at the same intensity. Seneye fwiw does not appear to subscribe to the same led testing outlined in apogees white paper on the subject.

 

[madweazl]

Lux has been so downplayed in reefing its become forgotten. It's not cool it's not fancy and it's not expensive. Led with the insanely controllable color combinations for really no purpose to most is very hard to do as the variables are so extreme.
I'm also fairly certain If you did do Lux par conversions at full intensity on the best leds it would show that they are not nearly as good as a mh or t5.
I'm absolutely dying to see it done on a Radion. Not that it would put me off buying one. Because again if it has the correct spectrum it may need more intensity to deliver it.
The seneye has a Lux function but I've seen a couple of user tests that make absolutely no sense whatsoever compared to the PAR of a mh at the same intensity. Seneye fwiw does not appear to subscribe to the same led testing outlined in apogees white paper on the subject.

What do you mean by, "If you did do Lux par conversions at full intensity on the best leds it would show that they are not nearly as good as a mh or t5?"

 

[saltyfilmfolks]

All of those Dana Riddle articles are insanely old and don't pass any muster today unless you have actual conversion factors for modern LEDs. I have yet to see any post from you posting the conversion factors for any of today's most popular modern light units. You keep quoting his articles and he clearly states that a different conversion factor is required for every single light source as the spectrum is different. So once again, where are your conversion factors with your recommended lux numbers?

Let's take just one single example from the chart. Ushio 10K and Coralife 10K. Both 10K bulbs. Conversion factors could not be any more different. 54 vs 30 is almost 2:1. You tell both guys they want around 40000 lux. Ushio guy will be pushing 740 PAR while Coralife guy will have 1333 PAR. You don't see anything wrong with that?

That scenario above is even worse with modern LED fixtures where people can switch the spectrum with the push of a button to something completely different than what they had 5 seconds before. Now you are being petty is saying that the difference is 14 PAR when in reality the difference can be huge.

Well first I obviously don't have a par meter. Second I don't have access to every light made. I do have the means and knowledge to build a Blak box to par map a fixture though. That's pretty easy. And if you look at the first post I actually did do that on the most popular box. A mars Aqua.

Also once you start doing the easy math involved you begin to see a range that all our fixtures fall into.

As far as danas articles I'd like to see you say that to his face. Second yes the led is out of date. But I don't think the halide has changed. Third although some seem to take those words as gospel, upon meeting him and his peers itbacame mich more clear that he and they are studying single data points. Those data points are to be used in further research by other scientists for the larger study of the subject as a whole. That's how science actuall works. Case in point red led article remember that furor? Also Po in aquaria is another good example. Hobbiests read it as gospel on parameters but in fact it's reccomend to easily balance a home system. If you take those same numbers and increase ne factor it effects the others and produces different results And those may very well be beneficial.

And I'm confused as to how 14 par can be confused as anything other than 14 par. Unless you mean you traded blue for yellow. And still that's 14 par. Pretty sure you lose that with dirty glass or a pod bloom

The las paragraph makes. No sense. Why would you use the conversion factor of two completely different bulbs. Seems you may be implying I use the same factor for a t12 full spectrum as a kessil. I'd reccomend you go back and read my first post in this thread.

 

[saltyfilmfolks]

What do you mean by, "If you did do Lux par conversions at full intensity on the best leds it would show that they are not nearly as good as a mh or t5?"

Look at dana or apogees chat on mh and t5.
Those conversion constants at less than 50 generally. A mars Aqua from a years research and par Lux data from users seems to be a Around 60. That's at a 1to1 ratio both channels.
If you take a Radion at full 1to1 all leds and did a par lux comparison what would that conversion constant be? My bet is that is in the 50's not the 30 or 40 as many t4 and mh are.
All that really means is it has to be brighter or has more intensity to achieve the same par as mh t5.
I will still grow coral.

 

[Daniel@R2R Verified Admin]

Look at dana or apogees chat on mh and t5.
Those conversion constants at less than 50 generally. A mars Aqua from a years research and par Lux data from users seems to be a Around 60. That's at a 1to1 ratio both channels.
If you take a Radion at full 1to1 all leds and did a par lux comparison what would that conversion constant be? My bet is that is in the 50's not the 30 or 40 as many t4 and mh are.
All that really means is it has to be brighter or has more intensity to achieve the same par as mh t5.
I will still grow coral.

That's an interesting speculation. It's actually reverse of what I would expect. Generally PAR readings on LED's are higher comparatively when tuned to the same visual spectrum. So LED's look (to the naked eye) like they are putting out less light even when achieving the same PAR reading as a mh or T5. That's one reason why so many people burned up their corals when switching from mh to LED...they tried to match the output visually.

 

[saltyfilmfolks]

2) Without understanding the difference between LUX and PAR or how corals use light, trying to use LUX could actually be detrimental to your livestock (as it can give a false sense of security if misunderstood).
3) PAR is definitely a superior measurement for reef tanks, but LUX meters are an affordable substitute if used as a "better than nothing" solution with recognition that they are inferior to PAR meters.
4) Using any blanket statements about your corals will do best under X amount of LUX is a bad idea because of variations of PAR under the same amount of LUX.

Is that a fair summary?

Umm yea kinda
1...yes
2...no. Not really IMO in as much as folks regularly dose mineral alk when thier nutrients are actually out of whack and if you don't know how to use a par meter with a six channel led how do you blindly decide how to increase or decrease what. So detrimental is relative
3....superior if you really really really belive that par changes that much from place to place in a tank even though the light all comes from above
4....no. If you tell me what fixture you have I can pretty closely tell you the rang you want to be in SAFELY an then acclimate from there.
A mars Aqua will throw 100,000 lux at 12 in at full no matter how you crunch those par numbers it'll fry a 20g. Your best off at 15 to 20,000 to start and go up from there. 1500 to 2500 a week depending on livestock and rock work.
ESP when you consider the olden days we took a couple mh on a 55 to grow shrooms routinely as corals are adaptable to a point.
Paruse par maps in google image and you'll begin to see what I mean. The same corals in vastly different par ranges. And I do always reccomend acclimation. Unlike our friend here Russ who has 1500 par at the top of his tank and will drop any coral right in.

This kinda leads to part of rich Ross and Sanjay talk at macna. Why are we afraid of it when we didn't used to be ? Because now we can test for it.

As always I do reccomend to everyone reef the the way you want to. And do what's comfortable for you. But don't bash my canister filter because it works it just has special requirements to make it work well.
There's pros and cons to Every thing.

 

[gus6464]

Well first I obviously don't have a par meter. Second I don't have access to every light made. I do have the means and knowledge to build a Blak box to par map a fixture though. That's pretty easy. And if you look at the first post I actually did do that on the most popular box. A mars Aqua.

Also once you start doing the easy math involved you begin to see a range that all our fixtures fall into.

As far as danas articles I'd like to see you say that to his face. Second yes the led is out of date. But I don't think the halide has changed. Third although some seem to take those words as gospel, upon meeting him and his peers itbacame mich more clear that he and they are studying single data points. Those data points are to be used in further research by other scientists for the larger study of the subject as a whole. That's how science actuall works. Case in point red led article remember that furor? Also Po in aquaria is another good example. Hobbiests read it as gospel on parameters but in fact it's reccomend to easily balance a home system. If you take those same numbers and increase ne factor it effects the others and produces different results And those may very well be beneficial.

And I'm confused as to how 14 par can be confused as anything other than 14 par. Unless you mean you traded blue for yellow. And still that's 14 par. Pretty sure you lose that with dirty glass or a pod bloom

The las paragraph makes. No sense. Why would you use the conversion factor of two completely different bulbs. Seems you may be implying I use the same factor for a t12 full spectrum as a kessil. I'd reccomend you go back and read my first post in this thread.

You spit out random lux numbers that people need to get to and don't take into account their fixture or spectrum. For the Kessil AP700 you specifically said it has low lux numbers so the PAR must be low without having a single clue to what the spectral graph or conversion factor is of that light.

 

[saltyfilmfolks]

That's an interesting speculation. It's actually reverse of what I would expect. Generally PAR readings on LED's are higher comparatively when tuned to the same visual spectrum. So LED's look (to the naked eye) like they are putting out less light even when achieving the same PAR reading as a mh or T5. That's one reason why so many people burned up their corals when switching from mh to LED...they tried to match the output visually.

Very likely yes.
And why I reccomend a meter of any kind
Even I during the course of the day will look at the tank and say whoa it's dark.

Because if you do for some reason get a light meter you will be amazed at the amount of light our eyes can see in. Bright or dark. Your house is probably 100 lux or less. And the kitchen is bright. 150 lux.
We have the second or third best eyes on the planet.

 

[gus6464]

You should read that article. They list different bulbs. Par has the same problem with diffusion there an apogee formula now addressing it. The two half way decent lux apps use the camera. It says so.

Way to completely misrepresent the apogee immersion factor. The new sensor has a cover that is not clear like the old one so it requires a compensation factor when it's under water. In open air it does not require it. That is totally different than doing a bunch of different calculations per spectrum wavelength.