Anyone Thinking of Dumping LEDS and going back to Halides

[shred5]

He is not using a par meter, also only some consumer grade low cost par meter have that issue.
The bottom line is that a 90w Kessil is not a replacement of a 250w metal halide lamp as their efficiency are similar.

http://www.apogeeinstruments.com/quantum/

Actually that had been fixed.
Apogee released the SQ/MQ-500 and the SQ-420 sensors which fix the issues and anyone with the older type can upgrade for a cost.

Not saying he didn't use a older one but letting people know the problem is fixed with newer models.

 

[dkeller_nc]

And yet, I've seen others who have had success with acropora using Radions. Confuzzled stuff...

Yep. I should re-emphasize that generally all SPS that I have except for acropora do quite well. And in the case of acropora not all colonies do poorly, just most of them. One possible difference is that I do not buy frags or named corals. They are all generally maricultured colonies that have done well for 4-8 weeks (sometimes much longer) under MH in a tank. So it may simply be that certain acropora strains that have been pre-selected in the aquarium hobby do well under any sort of light of sufficient intensity.

Indeed. Personally I've never liked the look of an all T5 tank. I'm also not a fan of high K MH. I just don't like the blue shifted look.

As to the missing green in LEDs I'm a little surprised that the Luxeon lime has not found wider use in LEDs. For those fixtures using them, the colour balance, with the appropriate settings, is quite good.

There is one company that I'm aware of that makes use of the lime green diodes - Nanobox. They get high marks for color rendition.

 

[oreo57]

As long as you take all those factors into consideration, you can figure out how much light you're really getting.

Get a PAR meter - you'll be happier

Def. agreement there..

Using raw output is "almost" pointless.
An easy way to think about it is if you turned a MH upside down....Great light output but practically zero to the tank..
but one does need to start somewhere..

ONLY a in vivo measurement will be worth much of anything..

FYI.. a Kessil light distribution at 24" plot:

One can see where a decrease or parity in efficiency can still lead to a higher "effective" delivery..

http://www.myledlightingguide.com/led-versus-traditional-lamps-a-fight-between-unequals

 

[Wazzel]

Yep. I should re-emphasize that generally all SPS that I have except for acropora do quite well. And in the case of acropora not all colonies do poorly, just most of them. One possible difference is that I do not buy frags or named corals. They are all generally maricultured colonies that have done well for 4-8 weeks (sometimes much longer) under MH in a tank. So it may simply be that certain acropora strains that have been pre-selected in the aquarium hobby do well under any sort of light of sufficient intensity.

It could be an acclimation issues. I only buy captive propagated frags and have had no issues growing anything. Definitely one of those things that make you scratch your head.

 

[karimwassef]

Thanks oreo. Glad we connect on this.

I have a separate thread where I measure the power and PAR of different multichip LEDs and I've come to the conclusion that DIY fixtures are not all equal. Different chips from different sources are significantly different from their "ratings"

Any design that isn't confirmed with a PAR measurement is a wate of time.

I wonder what the statistical distribution of PAR and wall-plug efficiency in commercial LED fixtures would look like vs. their promise.

What I'm getting at is that the variability in LED results across different users may be because LEDs can be individually different.

It's not that LEDs are worse than Halides... It's that your specific LEDs are inferior compared to my Halides or my LEDs. Someone else buying the same fixture may have gotten a better batch of chips.

Without measuring PAR, it's a crapshoot.

 

[Wazzel]

Thanks oreo. Glad we connect on this.

I have a separate thread where I measure the power and PAR of different multichip LEDs and I've come to the conclusion that DIY fixtures are not all equal. Different chips from different sources are significantly different from their "ratings"

Any design that isn't confirmed with a PAR measurement is a wate of time.

I wonder what the statistical distribution of PAR and wall-plug efficiency in commercial LED fixtures would look like vs. their promise.

What I'm getting at is that the variability in LED results across different users may be because LEDs can be individually different.

It's not that LEDs are worse than Halides... It's that your specific LEDs are inferior compared to my Halides or my LEDs. Someone else buying the same fixture may have gotten a better batch of chips.

Without measuring PAR, it's a crapshoot.

I suspect the QC/QA is adequate enough that manufacturing difference should not come into play.

 

[theatrus]

I suspect the QC/QA is adequate enough that manufacturing difference should not come into play.

For a mainstream fixture yes. The Chinese black boxes are going to be all over the map.

 

[drummerboyevil]

For a mainstream fixture yes. The Chinese black boxes are going to be all over the map.

Wait, you mean you get what you pay for in this hobby?!

 

[oreo57]

Wait, you mean you get what you pay for in this hobby?!

Somewhat.. and not without a gooooood look...
To be honest the cheap "Bridgelux" chips run around 50 lumens/watt while current chips (some like the small smd5630's) are now pushing 200 lumens/watt.

"Old tech" Metal halides and t5's are still (and will continue to be) around 100lumens/watt

Now that is lumens..not PAR ..soo take that into consideration..

As the high output small emitters become more "mainstream" i.e cheaper by volume, things will adjust accordingly..

BTW even buying "name brand" i.e CREE doesn't necessarily mean superior chips.. All have "bins" of varying output and electrical characteristics..

Not even considering drive currents...

Pushing cheap Bridgelux to their specs (and probably greatly shortening their lifespan) can produce more or equal output to the finest CREE's run conservatively..

Point is it is not always easy to determine "if" you get what you pay for..

 

[karimwassef]

Unless you have a PAR meter... Then you'll know

 

[karimwassef]

By the way, theatrus has a thread on here about a DIY PAR meter and the latest from Apex is a good value (IMO). It's not the super expensive luxury item it used to be.

 

[drummerboyevil]

unless you have the NEW par sensor too...

 

[karimwassef]

Also, the binning constraint is a very important one. Most of what makes it into the crappy cheap fixtures or DIY chip sources are reject bins. Those LEDs are not all bad, but you need to know what you're getting to accurately determine life, PAR, and thermal management.

Cheap isn't always bad and expensive isn't always good...

But knowing and measuring what you have is good, and not knowing is bad...

If you know, you can always correct or even throw it away day 1. If you don't, you assume LEDs are bad after your corals shrivel up.

Knowledge is your friend...

 

[theatrus]

Manufacturers would also be buying or keeping in stock several bins (depending on how they can source them and availability), and blend chips in the fixture to maintain a consistent output to meet their minimum spec (you could get *better*, and I have no idea if anyone is calibrating output levels via software - with swappable emitter boards I doubt it).

The eBay chips are effectively the rejects, but usable - the more it costs the better it will be (kinda). LEDs from main US distributors for Cree/Osram/Lumileds/Bridgelux are generally not guaranteed to be any bin in the cut tape quantities, but in my experience are the middle of the road in desirability of bins (the cut reel will be sold for evaluation purposes, so they don't want to put the worst ones in the mix for a customer). If you're buying whole reels you can generally pick, based on availability (the upper end bins may not even exist in volume production or would only appear years later as fabrication improves) and who has a better purchasing contract than you .

 

[Jeddite]

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[dkeller_nc]

It could be an acclimation issues. I only buy captive propagated frags and have had no issues growing anything. Definitely one of those things that make you scratch your head.

Quite possibly. Though in general any of these colonies will hang out for 4-6 weeks in apparent perfect health, and then RTN in a couple of days, or STN over a period of a couple of weeks. However, frags of these same colonies seem to do quite well in a tank that I have that's run with T5HO. Moreover, many of these colonies are "second generation" propagated from the initial maricultured ones from Indonesia under MH.

Nevertheless, it could still be a light acclimation issue. It's unlikely to be intensity, since the PAR measurements come out quite closely. But it's certainly not impossible for it to be a spectral issue. Quite a number of these colonies color-shift under the Radions.

 

[Wazzel]

Quite possibly. Though in general any of these colonies will hang out for 4-6 weeks in apparent perfect health, and then RTN in a couple of days, or STN over a period of a couple of weeks. However, frags of these same colonies seem to do quite well in a tank that I have that's run with T5HO. Moreover, many of these colonies are "second generation" propagated from the initial maricultured ones from Indonesia under MH.

Nevertheless, it could still be a light acclimation issue. It's unlikely to be intensity, since the PAR measurements come out quite closely. But it's certainly not impossible for it to be a spectral issue. Quite a number of these colonies color-shift under the Radions.

Looking around it seems that most people that have success with LED started with LED from frags. Those that swap in a mature tank seem to have more issues. I have no clue on what is going on, but it seems to be common.

 

[Bpb]

Probably because those who start with LEDs already have their schedule and intensity settled and aren't constantly experimenting with settings and mucking everything up. Experimenting with different t5ho bulbs is different since most have the same spectral properties from 380-500nm or at least very similar. Changing out tubes seems to be a gentler process and not many people frequently swap out their Mh bulbs except for when they're spent.


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[oreo57]

But it's certainly not impossible for it to be a spectral issue. Quite a number of these colonies color-shift under the Radions.

not really unexpected.. Stick them outside and they'd probably color shift..
That is a spectral proportion thing I assume..
of course since spectum control is now in ones own hand instead of a manuf.. well that is an issue right there..

Of course the "opinion" of what is a "correct" color is just an opinion..
but people like "standards"..

 

[blasterman789]

One critical difference between LED and MH or tube is the vast majority of LED reef lights use optics while MH or t5s dont. Take a large 2 foot fresnel lens, mount it in front of your MH, and more than likely youll suddenly have intensity issues and bleaching. LED sources are great for coral. Collimated light sources not so much, and likely accounts for most of the problems with LED. Picked up some frags from a local guy with a 400 gallon display over the weekend. This guy had half a dozen acropora colonies 2 feet in diameter over growing the thing, and he was running all generic LED fixtures.