Trying to upgrade slowly

[twelvefive]

Background: 6ft 125 gallon with 4ft Ecoxotic Panorama LED's which have turned out to be really low on PAR readings. I need to upgrade.

Do you think 2 Reef Radiance dm-155e's by themselves would be more light than I have now? The Ecoxotics I have are only 80 led's total, that would jump me to 110 led's but they wouldn't be spread out as far... so I can't figure out if that's better or worse?

dm-155e specs:
15.75" long
55 led's
90* white/blue/violets (49 of the 55)
120* red/cyan/yellow-orange (6 of the 55)

Spaced like this:
----2ft-------|------2ft-------|------2ft----
|-----------Light-----------Light-----------|

 

[Ron Reefman]

It's not a bad fixture, but with as much white as there is in it, you really don't need the red, green and orange leds. The white will add more than enough of those spectrum. But the lenses are a good change from all 90 degree. The violets should be 120 degree as well.

 

[twelvefive]

But is it enough light for my tank to sustain softies and an anemone?

 

[jedimasterben]

Any way you cut it, you're going to need three of any of the Chinese light fixtures out there to cover a 72" tank.

To be frank, I'd avoid the fixture you're planning - the ultra-cool white LEDs they use are not capable of good coloration of non-fluorescent colors (basically, anything other than green and a very select few other colors) like you'd expect from a 14k metal halide. You want something that uses a neutral or warm white (4500K or less) as a base and then built up from there.

For the price, you cannot beat a Reefbreeders value fixture. It's an old design of mine, but will still give you better color than the Reef Radiance one you are looking at. If you want to configure the LEDs to what I would now suggest, it would be: CH1-10x warm white (3000-3500K), 8x 480nm blue, 9x royal blue. CH2- 22x 450nm royal blue, 6x violet

 

[Ron Reefman]

I'd go along with jedi on a couple of points. His suggested layout is 10 white leds and 39 blue (45 if you add in the violet). That's a 4:1 or 4.5:1 ratio. I'm not sure I would go all the way to 4:1, but look for something better than 1:1. It way too white. And given most fixtures will be more like 2:1 blue to white, you can look for a mix of whites warm, neutral and cool. But the less whites you have the more you want to lean toward warm white to get more red spectrum from them or add a couple of green and red leds. Personally, I wouldn't add red and green unless I was at least at a 3:1 blue to white ratio. And then I'd do 2 reds with 1 green, keep them close together and use 120 degree lenses (if any) and surround them with blue leds. Your eyes will mix the red, green and blue to look white, the corals will still 'see' red, green and blue because they don't have eyes like ours. Just my 2 cents worth.

And as he said, you are going to need 3 unless this is a FOWLR tank. The 'brick' shaped leds from China only do about 2' of end to end coverage. The OceanRevive does a bit better because it has a bigger led pattern in the fixture. And it just plain looks better and more modern anyway. But even with their fixture you'd be way better off with 3. And at $156 each, they are hard to beat. They were $199 when I got mine!

 

[jedimasterben]

I'd go along with jedi on a couple of points. His suggested layout is 10 white leds and 39 blue (45 if you add in the violet). That's a 4:1 or 4.5:1 ratio. I'm not sure I would go all the way to 4:1

The reasoning for that is not because it will be very blue - it won't be. Warm white takes FAR more royal blue to even out the color temperature than neutral or cool white does (especially if we're talking about the garbage high-K cool whites in most of these Chinese fixtures). In general, a 1:1 using cool white and royal blue will get around 12-14K, but takes 1:2 for neutral white to royal, and 1:3-4 for warm white and royal! I'm estimating the overall color temperature with both channels at 100% will be only around 14K.

And given most fixtures will be more like 2:1 blue to white, you can look for a mix of whites warm, neutral and cool. But the less whites you have the more you want to lean toward warm white to get more red spectrum from them or add a couple of green and red leds. Personally, I wouldn't add red and green unless I was at least at a 3:1 blue to white ratio. And then I'd do 2 reds with 1 green, keep them close together and use 120 degree lenses (if any) and surround them with blue leds. Your eyes will mix the red, green and blue to look white, the corals will still 'see' red, green and blue because they don't have eyes like ours. Just my 2 cents worth.

Should never mix different white LEDs together - there is overlap in their spectrum that should be avoided, and there is no difference to the eye when mixed with the proper combination of blue and royal blue. All you do is add complexity and use more LEDs that are all trying to do the same thing.

Green (530nm) is never a necessity in any LED fixture. Even crappy cool white LEDs have more than enough green in them. Red (630nm) isn't necessary at all when using a warmer white. Deep red (660nm) can be useful in certain situation when specific proteins need to be excited, but in a good high-CRI white, there is enough of this spectra to cause that excitation.