Are all PAR38 fixtures created equal?

[moonlightdriver]

Well as the title says, are are PAR38 fixtures equal in their ability to maintain a reef tank or can they even maintain a reef tank? I am setting up an 8ish gallon tank in my office with a buddy and we would like to use a PAR 38 LED fixture. We are looking to keep some basic corals in it and give our office mates a small taste of our hobby. As I'm sure some of you know there are different varieties if of these fixtures if you do a search for them on the net. I think i know the answer that there are cheapos and for example only the brands like Ecoxotics have the 3W LEDs in them. We are look to do this on a bit of a budget of course so we are looking for the cheaper fixture without sacrificing performance. Anyone with some experience with the knock offs or have any input as to if they would even cut it since the tank is so shallow? Its only about a foot deep.

 

[hotshot619]

I have 4 Par38s from Rapid LED going over my 46, from what I have learned in this hobby is you get what you pay for. (aka cheap is well cheap and are a waste of money) I would only recommend using Rapid LEDs or Evilc66's Par38 from Nanocustoms as from all I have read these are the tippy top of quality, but also pricey. I just mounted up one over a flu-val edge reef tank and it looks GREAT! I probably would be able to grow most LPS and down.

 

[der_wille_zur_macht]

They're not created equal.

LEDs are extremely deceiving in their variability. It's easy for two LEDs or two LED fixtures to look, sound, taste, and feel more or less identical, especially on paper, when in fact they may perform at vastly different levels in terms of intensity, power consumption, spectral profile, and spatial distribution.

For example, people toss around terms like "it's a 3W cool white LED." That's absolutely meaningless if you care about what the LED is actually doing. For one thing, labeling LEDs at a nominal power level is misleading, because that same LED might be running at vastly different power levels in different fixtures. It's one thing to say a particular MH lamp is a 250w lamp, because anyone using that lamp will effectively be running it at 250w. However, the same exact LED used in two different applications could very well be operating at vastly different power levels.

Further, the performance of LEDs that look the same can vary significantly. Even if you know the manufacturer and model of a particular LED, you really need to know the bin - different performance bins within a given model of LED can be off by 100% or more in terms of how much light they provide at a given power level.

And then we get to spectrum, where the differences can be at least as vast. This is the hardest to wrap our heads around because pretty much no manufacturers of finished units tell us enough info to be extremely well informed about spectrum and color. This is probably because most of them probably use a range of bins depending on what the manufacturer sells them any particular week.

Another major variable is optic choice - this can have a vast impact on spread and intensity. A fixture with narrow optics might produce 400 PAR over an 8" spread, while the same fixture with wide optics might produce 80 PAR over a 20" spread.

What it really boils down to is, unless you know the model and bin info for the LEDs in the fixture, it's a bit of a shot in the dark. In essence, your question is like saying "are all single ended MH lamps the same?" Well, no - there are different wattages of SE lamps, different colors, different manufacturers, different levels of efficiency - plus it depends on the driver and reflector, and so on.

 

[Jacwil]

I had a Nanotuners Par 38..love it but I think the business is faltering and people with orders in there are waiting big time, sooo I would wait on ordering from there unless you speak to them directly first.

I can't speak for any other brands myself.

As far as one lighting your 7g...absolutely. I believe I read that one could grow most anything in a 12" cube. You'll just have to experiment with height and spread and decide what type of optics you want as well as color. You'll also have to plan for what type of fixture you will use to house the lamp. It weighs about a lb so many of the multi-articulating desk style fixtures don't have the backbone to support it...but there are many out there to chose from, just remember to remove any shield it comes with so the lamp may cool properly.

 

[Jacwil]

Nice explanation Dweezum!

:beer:

 

[der_wille_zur_macht]

That was kinda long winded. I'll try a cliffnotes version: If you are collecting anecdotal evidence, I would try to be extremely specific about knowing exactly which brand/model/version someone was talking about. I have a handful of PAR38 fixtures at home but honestly I don't remember what brands or models they are so I won't give feedback at the risk of misleading anyone.

If you are researching from scratch, I would concentrate on the following points:

1) Try to determine exactly what brand/model/bin of LEDs were in the fixture
2) Determine at what current they are being driven
3) Determine what optics are on the fixture

Those are going to be the main variables and will help you compare from unit to unit.

I will say, one thing that seems to be missing from most of these is good wide-spectrum white lighting. Most of them use only cool white LEDs for white light, which tends to wash out the colors of some corals - this is why many DIY'ers and higher-end commercial fixtures are now starting to include neutral or warm white or even monochromatic red or orange LEDs.

 

[der_wille_zur_macht]

That was kinda long winded. I'll try a cliffnotes version: If you are collecting anecdotal evidence, I would try to be extremely specific about knowing exactly which brand/model/version someone was talking about. I have a handful of PAR38 fixtures at home but honestly I don't remember what brands or models they are so I won't give feedback at the risk of misleading anyone.

If you are researching from scratch, I would concentrate on the following points:

1) Try to determine exactly what brand/model/bin of LEDs were in the fixture
2) Determine at what current they are being driven
3) Determine what optics are on the fixture

Those are going to be the main variables and will help you compare from unit to unit.

I will say, one thing that seems to be missing from most of these is good wide-spectrum white lighting. Most of them use only cool white LEDs for white light, which tends to wash out the colors of some corals - this is why many DIY'ers and higher-end commercial fixtures are now starting to include neutral or warm white or even monochromatic red or orange LEDs.

 

[teamdulski]

nanotuners.com has a great par38. sometimes they have deals on them as well, i bought one off that site awhile ago for $89 with 60 degree optics. these are not the same as many other ones. you can even buy par38s at home depot, but they arent the ones youll be looking for. you can switch the optics out if you desire to 80 or 40 theyre like 2.50/piece. a 60 degree optic will give you around 18 inches of light 2 feet up, an 80 will give you around 2 ft of light 2 ft up...approximately

 

[teamdulski]

nanotuners.com has a great par38. sometimes they have deals on them as well, i bought one off that site awhile ago for $89 with 60 degree optics. these are not the same as many other ones. you can even buy par38s at home depot, but they arent the ones youll be looking for. you can switch the optics out if you desire to 80 or 40 theyre like 2.50/piece. a 60 degree optic will give you around 18 inches of light 2 feet up, an 80 will give you around 2 ft of light 2 ft up...approximately

Kyle, you could have at leasted posted using your account. I need to learn to log out.

 

[cardiffgiant]

I will say, one thing that seems to be missing from most of these is good wide-spectrum white lighting. Most of them use only cool white LEDs for white light, which tends to wash out the colors of some corals - this is why many DIY'ers and higher-end commercial fixtures are now starting to include neutral or warm white or even monochromatic red or orange LEDs.

This makes a lot of sense. I have experienced washing out of colors for paly's and some SPS with my 2 nanotuners par38's.

 

[Jacwil]

Yea...I agree...I'd like to see one of the new ones with a touch of red. I know there are a ton of variables but I wonder if it would look like a t5 tank with a fiji purple in the lamp mix...I wasn't a fan when I tried it but of course it could have been the combo I was using.

 

[der_wille_zur_macht]

Ok, the two I have on my 60g at this very moment are nanotuners 20k XR-E with narrow optics, according to the label. These are a little older, dunno if they have changed the product since then. They work just fine, but do definitely wash things out. To the human eye, it looks more like what I would call a 12 - 15kk look than a real nice deep 20kk look, yet it somehow manages to suffer from the one-dimensional washed out effect you get from some 20kk's.

These things are definitely very intense though, with the narrow optics (the label doesn't specify the width, unfortunately - but I would guess it's around 30 degrees. It's definitely narrower than the 40's I have on other LEDs right next to them).

Here is a photo to give you an idea of the color. This is a temporary holding tank so please excuse the random coral placement, rampant microbubbles, cyano, and the fact that the glass hasn't been cleaned in about 6 months. This is two of these lamps aimed at a portion of the tank that is maybe 18" square. You can see that it's pretty dark near the edges. The lamps are maybe 16" above the water and their "hot spot" is maybe 9" across, each.

 

[Gravesj1s]

I noticed a color difference by eye between 2 different t-5 fixtures both running a k-zuct figi purple bulb. On my fixture it appears more pinkish when lit and on someone elses I noticed it looks purple-ish.Exact same 4 bulb combo but two seperate brand manufactures

 

[zooman72]

DWZM has done a very good job of laying out the basics (or concerns if you will...), but there are a lot of others who have already served as "guinea pigs" and have used these LED PAR bulbs over their tanks, and who have reported various results - unfortunately color representation in photos is usually not correct when photographing LED's, but you can get an idea.

I think that, other than the Nanotuners/ Nanocustoms PAR bulbs, you may also want to look at the RapidLED PAR38's and the Boost LED PAR30's. I will admit that I use a BoostLED PAR30 over a 15 XH, and I do like the fixture, but as has been stated, it does appear washed-out to a degree. I think a PAR30 LED with 60 degree optics would be enough over an 8 gallon (and maybe too much depending on what you want to keep...), and both Rapid and Boost are now using colors in addition to the cool whites to address the washed-out effect.

Boost LED also has a nice "gooseneck" lamp fixture for their bulbs that is not too expensive and appears to be quite useful as a common complaint when using these bulbs is "how do I mount it?"...

 

[hotshot619]

I will post a picture up of how I have a Rapid LED over my nano when I get a chance. It will make you laugh for sure but thought you might like to see this guys 12 gal with one par38 bulb.
http://web4.reefcentral.com/forums/showpost.php?p=17937493&postcount=626

 

[teamdulski]

Mike at Rapid Led is the best, always helps me out with pricing on larger orders.