Question for LED owners

[mcarroll]

REgardless of what led make i used .. i always ramped up the blues all the way to 100 and always ran blues atleast 10 hrs at 100% ... never had a problem with it .. however was never able to ramp whites to 100% without having atleast few corals bleach on me ..

That's not a bad approach if you're going to "wing it". Consider doing the same thing aided by a lux meter (or PAR meter, if you have one already) where you could match your blues' brightness with the vendor where you bought the coral. (Cuz they run all blue too.) That gives you a great baseline to start your new corals because it's identical to your store's levels where the coral was before. You can take your time bringing up the main lights, and if needed, dialing down the blues. You'll be able to make much more exact changes and make fewer mistakes guided by a meter. It's actually easy to exceed full daylight conditions with many reef lights - this is where at least some of the mystery bleach-outs happen.

As much as I'd like to agree with you I can't. I quoted watts in how many led's I use but in all honesty there is only a casual relationship between watts and lux. You can take two led fixtures that pull the same wattage and yet produce different amounts of lux. Same goes to comparing a 400watt MH to a 400watt led. Lux is probably going to be quite different. The thing is watts is a measure of energy used and not a measure of light output. One of the selling points to high end led's is that they are more efficient producing more lux per watt than low end fixtures. All this makes comparing different lights almost impossible without a listing of the lux output not to mention comparing pinpoint lux values to overall spread. So you need to know the height above water and the actual area being lit and the average lux over the entire area and that doesn't include penetration depth in each individual tank. Lux meters can be a very useful tool but many of us simply rely on watching the corals and seeing how they react to the tank lighting to decide if the lux value is high enough.

The relationship really isn't that casual at all - don't buy into that overcomplexity. (Please?)

Differences between 400 watt halide bulbs are minute, and the more we learned about them back in the day, the more people realized that there was a correct mounting height for the different bulb wattages. Virtually nobody used a meter though, so there was a ton of guessing and, naturally, lots of mixed results.

Once part of an integrated light fixture, the efficiency differences among LED's are similarly small and anyone operating without a meter is almost assured of the same mixed results we metal halide users experienced back in the day. Of course that means some will succeed, but it'll be a predictably low percentage vs folks actually measuring what they are doing. (Worth restating that we're talking about a $15 meter. Nothing fancy.)

You want the correct spread for your tank size so you aren't wasting light over the edges of the tank, but you also want the correct intensity of light (about 30,000 - 80,000 lux). Without a meter, how are you supposed to know where the "edge" of your fixture's useful light is, or what the actual intensity is at the height your light is suspended? You either guess, or rely on manufacturer charts which are often hard to interpret in their own right. A $15 meter answers these questions.

It's really as simple as this: If you are generating daylight conditions (your actual requirement) as measured at the water surface, then by definition you're creating the correct below-water conditions for many corals. It's that simple, and you can make pretty much any LED system work by knowing and using that simple fact...with a meter. And comparing LED's isn't that hard either...provided you have all the info.

Some real life examples:

• If it's taking me 160 watts to satisfactorily light a 50-breeder (36x18), then it'll take you about the same watts with another light, all else (lenses and layout) being roughly equal. (In fact, this light hangs at about 9" from the water surface and spills a fair amount of light over the front and back since the layout was designed for a more cube-shaped tank, so there are some "waste" factors, but most people just accept these things, so I'm typing them in parenthesis. )
• To show how even wildy different LED's can be reasonably compared, let's take a closer look at my 36x12 tank. This was custom, so the light was designed for the tank. This means there is no light-spill, and I rarely have to scrape the glass. The light makes use of 1 watt LED's, 30º (gives a x3 intensity bonus) lenses and a different layout, but creates about the same daylight intensity as the first tank. Thanks to the lenses, the tank only needs (150 watts / 3 = ) 50 watts of actual LED's. In reality, measuring actual current usage, this light uses around 40 watts.

There is no black magic and, assuming my examples make any sense, the comparison isn't that tough to make even on these two VERY different lights.

I hope this makes sense!

 

[ca2or]

I listen to everyone, even those I don't agree with, and the only ones I ignore are those who'll tell you up front that their way is the only way you should be doing something.

Best line of the day for me.

 

[Devlin]

Devlin you'll find that any topic here will give you a wide range of views. This can come in handy especially if you have an issue with your tank. As always research from as many sources as you can find and then take your best guess. It's what we all do at one time or another. I listen to everyone, even those I don't agree with, and the only ones I ignore are those who'll tell you up front that their way is the only way you should be doing something.

I use everyone's info to a certain extent. I make sure my levels are good and adjust my lighting as to the way the corals respond. I'm getting 2 polyp's a month from my zoas right now and everything else in my tank seems to be happy. I have more fish than I should but I'm running carbon and have a tunze 9001 skimer running. Do water changes every other week. Dosing magnesium to keep the algae at bey. Feeding zooplankton every other week.

 

[Harold Green]

That's not a bad approach if you're going to "wing it". Consider doing the same thing aided by a lux meter (or PAR meter, if you have one already) where you could match your blues' brightness with the vendor where you bought the coral. (Cuz they run all blue too.) That gives you a great baseline to start your new corals because it's identical to your store's levels where the coral was before. You can take your time bringing up the main lights, and if needed, dialing down the blues. You'll be able to make much more exact changes and make fewer mistakes guided by a meter. It's actually easy to exceed full daylight conditions with many reef lights - this is where at least some of the mystery bleach-outs happen.



The relationship really isn't that casual at all - don't buy into that overcomplexity. (Please?)

Differences between 400 watt halide bulbs are minute, and the more we learned about them back in the day, the more people realized that there was a correct mounting height for the different bulb wattages. Virtually nobody used a meter though, so there was a ton of guessing and, naturally, lots of mixed results.

Once part of an integrated light fixture, the efficiency differences among LED's are similarly small and anyone operating without a meter is almost assured of the same mixed results we metal halide users experienced back in the day. Of course that means some will succeed, but it'll be a predictably low percentage vs folks actually measuring what they are doing. (Worth restating that we're talking about a $15 meter. Nothing fancy.)

You want the correct spread for your tank size so you aren't wasting light over the edges of the tank, but you also want the correct intensity of light (about 30,000 - 80,000 lux). Without a meter, how are you supposed to know where the "edge" of your fixture's useful light is, or what the actual intensity is at the height your light is suspended? You either guess, or rely on manufacturer charts which are often hard to interpret in their own right. A $15 meter answers these questions.

It's really as simple as this: If you are generating daylight conditions (your actual requirement) as measured at the water surface, then by definition you're creating the correct below-water conditions for many corals. It's that simple, and you can make pretty much any LED system work by knowing and using that simple fact...with a meter. And comparing LED's isn't that hard either...provided you have all the info.

Some real life examples:

• If it's taking me 160 watts to satisfactorily light a 50-breeder (36x18), then it'll take you about the same watts with another light, all else (lenses and layout) being roughly equal. (In fact, this light hangs at about 9" from the water surface and spills a fair amount of light over the front and back since the layout was designed for a more cube-shaped tank, so there are some "waste" factors, but most people just accept these things, so I'm typing them in parenthesis. )
• To show how even wildy different LED's can be reasonably compared, let's take a closer look at my 36x12 tank. This was custom, so the light was designed for the tank. This means there is no light-spill, and I rarely have to scrape the glass. The light makes use of 1 watt LED's, 30º (gives a x3 intensity bonus) lenses and a different layout, but creates about the same daylight intensity as the first tank. Thanks to the lenses, the tank only needs (150 watts / 3 = ) 50 watts of actual LED's. In reality, measuring actual current usage, this light uses around 40 watts.

There is no black magic and, assuming my examples make any sense, the comparison isn't that tough to make even on these two VERY different lights.

I hope this makes sense!

It may be beating a dead horse but I say again wattage is not a measure of lux. A heater element is measured in wattage yet produces very little lux.

 

[rovster]

It really comes down to personal preference between the different lighting options nowadays. Each has its advantages and disadvantages. Switching from MH to LED is not to complicated but people make it out to be. Because you can adjust the color temp of LED they think it is. If I am switching light sources I set the LED to the color temperature I plan to use and I turn down the intensity or raise the fixture. Over the next month or so I slowly turn up the intensity or lower the fixture. I find if the new coral came from a hight light source I was safely able to put it at mid tank level with no issues for the most part.

100%

Facts:
LEDs will grow and color any type of coral
Coverage is more important than intensity
LEDs are trickier to set up, start slow and let the tank do the talking
LEDs are deceptively dark. With MH and T5 it "looks" like they put out more light
LED gives you nearly unlimited possibilities with colors and programs

I have first hand experience running 4 radions over a 52" length at 60%. I recently added2 T5 not because I was unhappy with the led but because I'm a tinkerer and like to mess with things.

All lights have their pros and cons. Just have to figure out what you want and what you're willing to give up....

 

[Harold Green]

I'd like to add when you change to led lighting add a fixture more than the amount you think you need. Turn the intensity down and slowly ramp up as you find the corals can accept more. The added led's will allow you to color adjust without not having enough intensity.

 

[Quinn123]

Two radion. 100% blue and 60% white
Don't think my corals are growing at all after switching from metal halide
If not for the heat,electricity cost and bulbs replacement every eight months, my choice of light would be metal halide all the way.

 

[mcarroll]

It may be beating a dead horse but I say again wattage is not a measure of lux. A heater element is measured in wattage yet produces very little lux.

But if you take a 75 watt light and a 75 watt heater and seal each one in a box with a thermometer, you'll find they do produce the same amount of heat. Every photon produced ends up as heat. Try that in an experiment!

We know watts is not literally a measure of lux, but...

Watts is "a measure of lux"...as filtered through a roughly 90% efficient power transformer and about 90% efficient LED's on average.

• So no it's not precise, but it's close enough that if you know what you're talking about (layout, lenses and power) you can still pretty easily estimate a tank's light requirements in watts. (And I do. Frequently.)
• Once you have eliminated that mystery, there will be a correct mounting height for every given light fixture, and that height is based on not spilling light over the sides of the tank. (YMMV, but I don't like wasting light or the "reef light effect" a room gets from all that spilled light.)
• Last, the lighting system's dimmer is used to dial in the correct intensity with a PAR or lux meter.

I hope that's a more agreeable way of thinking about it.

BTW, having fixtures designed to light (e.g.) 24"x24" patches of tank (i.e. squarish tanks) over rectangular tanks (a mismatch) is the reason why you have to give the advice to "use more fixtures than necessary" and turn them down. More often than not, there's a lot of light spilling in these setups. Again, YMMV, but the waste and room-lighting-effect both annoy me.

 

[mcarroll]

100%

Facts:
LEDs will grow and color any type of coral
Coverage is more important than intensity
LEDs are trickier to set up, start slow and let the tank do the talking
LEDs are deceptively dark. With MH and T5 it "looks" like they put out more light
LED gives you nearly unlimited possibilities with colors and programs

I have first hand experience running 4 radions over a 52" length at 60%. I recently added2 T5 not because I was unhappy with the led but because I'm a tinkerer and like to mess with things.

All lights have their pros and cons. Just have to figure out what you want and what you're willing to give up....

You're just describing life without a light meter.

A $15 lux meter could change your whole view.

 

[mcarroll]

Now that's an interesting approach. So a lux meter is what one would need?

A ($15) lux meter is the most affordable way I know to stop guessing about your lighting setup, and it does work.

 

[mcarroll]

REgardless of what led make i used .. i always ramped up the blues all the way to 100 and always ran blues atleast 10 hrs at 100% ... never had a problem with it .. however was never able to ramp whites to 100% without having atleast few corals bleach on me ..

I forgot to add that technically if you had corals bleach on you, then it wasn't problem-free. That's a good example of a situation that's completely avoidable just by using a $15 lux meter or PAR meter.

 

[WesF]

lux readings can be deceiving since it's basically a measurement of perceived brightness. So certain wavelengths (ie red, blue, green) can have relatively low lux readings while still emitting quite a bit of PAR.

Since 99% of reefers aren't running their lighting at 5000-6000 Kelvin it's difficult to make that comparison of lux readings at the water's surface in nature.

 

[mcarroll]

I do it all the time and explained the wide tolerances that allow it earlier in this thread. For other purposes that accuracy may be an issue - for this use it is not.

 

[thereeferdude]

lux readings can be deceiving since it's basically a measurement of perceived brightness. So certain wavelengths (ie red, blue, green) can have relatively low lux readings while still emitting quite a bit of PAR.

Since 99% of reefers aren't running their lighting at 5000-6000 Kelvin it's difficult to make that comparison of lux readings at the water's surface in nature.

Finally! All this talk of lux and watts was making the vein in my forehead bulge a bit. PAR and more importantly, PUR, are much better measures of what I am interested in when determining what my corals need. These may be a bit more costly to measure accurately, but lux is a measure of what I SEE, not what the photosymbionts in my corals USE. Human eyes just don't perceive the most important wavelengths involved in photosynthesis very well.
I could have a poorly designed, high lux fixture that doesn't hit the PUR values my stick babies need. I do follow the logic and wisdom shared in this discussion, but oversimplifying the issue can mislead some folks.

 

[ca2or]

A ($15) lux meter is the most affordable way I know to stop guessing about your lighting setup, and it does work.

Where can I get one?

 

[mcarroll]

[...]I could have a poorly designed, high lux fixture that doesn't hit the PUR values my stick babies need.[…]

...not using reef lighting and the outline I've posted you can't.

 

[mcarroll]

Where can I get one?

Amazon and eBay...anyplace like that.

 

[ritter6788]

An iPhone has a free lux app. It's identical to my Milwaukee lux meter if you're wanting to go that route. I've seen it mentioned that if you divide lux by 50 you get a crude estimate of par.

 

[mcarroll]

There are a dozen or more lux : PAR conversion factors that have been published. There isn't a ton of variance between conversion factors known so far.

 

[mcarroll]

My luck with the lux apps has been mixed. Some have worked for me, but not for others. I think some apps can't control the aperture correctly on some cameras and end up with low or variable readings. Just be aware and try another app if you get weird readings. (A $15 handheld meter may be worth it.)

$0.02