21USALED 50w 12k single led users?

[Dburr1014]

Does anyone have any experience with these bulbs? Is this truly an alternative to metal halide?

 

[oreo54]

Does anyone have any experience with these bulbs? Is this truly an alternative to metal halide?

Now you are just trying to stir up trouble.
:astonished-face:

"Truly an alternative" is a pretty loaded question.
In my fw world they are used all the time. In sw there are def "use-able" with the caveats below:
Match the par output.. certainly with enough watts.
Historically the replacement of legacy lighting w/ leds followed a trend of 1W led to 2W "other" to get the same par..seems to work everywhere.... except here.
Why ?? No clue.
I'd not start lower than 1W led to every 1.5W legacy with the output tailored to what you want the par to be. Actual measurements are all over the board though.
Match the "tone" no
Have a "full spectrum" as some have defined it.. no

fw or sw my biggest err "complaint" is all the electronics are smack dab on top of the LED heat.
Led tend to radiate heat up not down. As such buying a spare or 2 is a wise decision.
In other words don't have the greatest longevity.
It's even possible they only last about as long as a MH bulb does.:)

What they do have is a lot of royal blue in the spectrum and little or less heat directly radiated into the water.
Spreads generally around 120 degrees so they can cover tanks fairly well though that means low mounting heights and subjecting them to higher environmental stresses though many are sealed so there is that.

Now as to what they can do or those that use them, pretty sure they are not exactly popular so your data base is going to be a bit err skimpy.
Now there could be some users who don't want to admit it.. for various reasons..

https://forums.reefcentral.com/thre...-seagrass-tank.1725963/page-157#post-28657903
Note, why 171 pages on seagrass..????
Sadly they could be a LOT better with the right phosphors (and maybe shifting the blue base to a lower nm, or both) but apparently that isn't going to happen.
Anyways, enjoy.

 

[Dburr1014]

Now you are just trying to stir up trouble.
:astonished-face:

"Truly an alternative" is a pretty loaded question.
In my fw world they are used all the time. In sw there are def "use-able" with the caveats below:
Match the par output.. certainly with enough watts.
Historically the replacement of legacy lighting w/ leds followed a trend of 1W led to 2W "other" to get the same par..seems to work everywhere.... except here.
Why ?? No clue.
I'd not start lower than 1W led to every 1.5W legacy with the output tailored to what you want the par to be. Actual measurements are all over the board though.
Match the "tone" no
Have a "full spectrum" as some have defined it.. no

fw or sw my biggest err "complaint" is all the electronics are smack dab on top of the LED heat.
Led tend to radiate heat up not down. As such buying a spare or 2 is a wise decision.
In other words don't have the greatest longevity.
It's even possible they only last about as long as a MH bulb does.:)

What they do have is a lot of royal blue in the spectrum and little or less heat directly radiated into the water.
Spreads generally around 120 degrees so they can cover tanks fairly well though that means low mounting heights and subjecting them to higher environmental stresses though many are sealed so there is that.

Now as to what they can do or those that use them, pretty sure they are not exactly popular so your data base is going to be a bit err skimpy.
Now there could be some users who don't want to admit it.. for various reasons..

https://forums.reefcentral.com/thre...-seagrass-tank.1725963/page-157#post-28657903
Note, why 171 pages on seagrass..????
Sadly they could be a LOT better with the right phosphors (and maybe shifting the blue base to a lower nm, or both) but apparently that isn't going to happen.
Anyways, enjoy.

Me? Stiring up trouble? No way. :p

I understand all your points. It says they have a 17 year life, mm, probably not.
If they were an alternative, I would definatly run blue T5 with them.

Thanks for the input!