I'm upgrading to LED

[zygote2k]

I saw one of the nanotuners' PAR38 LED bulb on a smalll tank and was thinking about using 3 of them to light my new 60 cube. I'm thinking that I don't need to light the whole tank but could get away with spotlighting 3 main areas of the tank and put the high light demand corals there. I have a question of which lense spread I should use: 40, 60, 80 degree?

Here's a pic of the bulb-

Edited January 26, 2010 by zygote2k

[ctenophore]

Try one of each to balance high PAR needs and spread. What color temp are you going with? Keep in mind that blue LEDs put out more PAR than white IIRC. I think PFO showed this with their solaris fixtures.

 

I will get some pics of the nano up soon (it's my daughter's tank Rob is talking about)

[zygote2k]

I was thinking about getting 2 12k's and 1 20k. Maybe I could get one with a mix of red, blue, and white too. I wonder if the individual colors can have different lenses?

[igozoom]

If you're going to have just 3 corals, clams, or anemones in the tank, I'd get the 30 degree spread (these would also be good for locking and anem into a specific location. The spread would depend on how much you want to 'spotlight' each light point and the distance from the surface of the water. What Evilc66 fails to concede in his lengthy diatribes about LEDs is that if you get the LED close enough to the surface of the water, the (<2") you don't need to get the native 60 degree more focused via a lens. You'll see the spread becomes 50% tighter focused if the get the light right above the surface of the water. If the 80 degree 'bulbs' do not include lenses (colimiters) I'd get that one. The lenses cut the 10% of your light output, which is a big deal when you add up how many of these things you'll need to get as much par as a metal halide.

Edited January 26, 2010 by igozoom

[Larry Grenier]

Sorry to butt-in but (pun intended)...

 

Wouldn't the 80 degree be the way to go?

 

Isn't an inheritent problem of leds the fact that they are too focused?

 

Cool subject (pun intended again)

[chucelli]

Lenses or optics may cut light output, but the amount you will be gaining more than offset the relatively negligible loss.

I would recommend a fixture with some type of optics, since the amount of light wasted (bleeding out the sides) without optics are not trivial.

I would choose 40˚ for high mount (>4' from water surface, and 60˚ of anything less than that. 80˚ if you are more concerned with coverage over intensity.

Also keep in mind, that comparing these LEDs to MH is not as easy as deciding how many you will need. With 40˚ optics and lower mount height, you can easily surpass any 400w MH output in a given area and end up bleaching your corals. I suggest borrowing the club PAR meter and running some tests.

-Robert

[chucelli]

Rob, do you know at what current these PAR38 bulbs are driven?

-R

[bluefunelement]

You can look at the threads showing the plots to see what diameter output you'll get at what distance then you can also buy a small LED setup to test different optics - 2 LED +driver + optics <$50 to test with.

 

I'm looking at 40 as I want to keep some height off the water but if I had a 60cube I'd likely go with 60optics so I could mount them closer to the water and still get more coverage.

 

PAR38 PAR plots

[chucelli]

I think 40˚ optics is a good idea simply because you have more options when it comes to intensity vs. coverage. All you have to do is adjust mount height to acquire desired intensity/coverage.

The best thing to do would be to get some PAR readings from these lamps.

Seeing that it is passively cooled, my bet is that they are running at 350mA, a very conservative setting to prevent overheating.

Just for reference (from Cree's datasheets):

XR-E outputs in lumens:

107 lum@350mA

160 lum@700mA 33% increase in output

210 lum@1000mA 51% increase in output

-R

[igozoom]

Are you installing these on a light track?

[zygote2k]

I need to figure out some way of making a bar that goes across the top of the tank that 3 lamps can get mounted to. I was thinking about some sort of track lighting, but I think that uses low voltage... I need help from the creative types here. Any ideas?

[ctenophore]

I need to figure out some way of making a bar that goes across the top of the tank that 3 lamps can get mounted to. I was thinking about some sort of track lighting, but I think that uses low voltage... I need help from the creative types here. Any ideas?

I believe Home Depot has a regular socket track light. Just look around their light display. You may need to pull/cut the lamp hoods off the fixtures.

 

One of those flexible tracks would look really nice. Bend it into a circle so that you can light the pillar from all sides, then you can raise or lower depending on PAR needs.

[bluefunelement]

The PAR20 is underdriven but I thought the 38's were overdriven-

[zygote2k]

I got all 3 of them today and just for a quick look, decided to use a clamp lamp and shine it into the tank. The lamp was at 45 degrees and the light surface was about 6" off the water. The area that is lit up in the picture is about 8" below the surface. It's pretty bright considering there is already a 400w mh and 64w of PC at the same time. I think 3 will suffice to replace the 400 fixture.

[dtfleming]

Did you talk to Evilc66 on NR. He made them and he has some pretty good charts with PAR reading with the different optics. Tracking would work. You dont want to enclosed the back of those lamps due to heat. Im looking at doing two on track lighting over a 20H with the 60deg optics.

[zygote2k]

It looks like I'll be going with a 3 bulb chandelier suspended from the ceiling. The bulbs will be open to air to allow for proper ventilation.

Here's another pic:

[davelin315]

Lowe's has flexible extension sockets. It's basically a socket that screws into an existing mogul base and then runs out through what looks like loc-line and you can bend it to what you want. They're about $15 if I recall correctly. I have a couple of them that I was trying to use with red lights to see at night (haven't gotten around to installing) and I took a reflector out of a recessed lighting fixture and put them into each one. Those might work well for you as you could simply put some mogul bases against the wall and bend these to where you want them. Lots of options.

[zygote2k]

the beginning of the LED craze on WAMAS- although at this time, Chucelli was building them already....

[monkiboy]

the beginning of the LED craze on WAMAS- although at this time, Chucelli was building them already....

haha, if you need any PAR38 bulbs, i got a great group buy going!

[zygote2k]

Using Par 38's in a massive array is my absolute favorite way to light a nice reef tank. Combined with the right reefscape, you can have high light zones, low light zones, striated lighting, and very nice shadows. Easy to build too.

The current trend of LED box lights is kind of boring and seems to be a recreation of T5 fixtures.

[Sharkey18]

Yes but they are easy.....