# PAR38's



## kingfisherfleshy (Jun 4, 2010)

Hey guys...I did another LED thread awhile back, and just want to bring up PAR38's because there is a chance that it might be cheaper or more expensive to go that route. The other advantage is that I would probably buy one that was dimmable. 

Anyone that has used them should chime in on what they are using, how they like it, what they dont like about it etc. 

I have a standard 10g tank, eco complete substrate, RM complete tabs, and pfertz low tech fertilizers, I also use DIY co2, and dose excel. 

I am willing to upgrade fertilizers to do some, and I was supposed to be getting a paintball co2 system in the mail...but Im pretty sure the seller ditched on me. If need be, I would get another to make sure I didnt have too much light. 

So let me know what you are using, and what I would need to do to start using leds as well (As far as ferts and co2 go)

Thanks!


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## audioaficionado (Apr 19, 2011)

I'd like to know too. Using dimmable PAR30/38 LED bulbs could be less expensive and easier to manage in the long run. Most of the buz here and at the reef sites is total DIY programmable sunrise to sunset arrays and that might be why no one is really getting interested in this LED deployment method.


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## kingfisherfleshy (Jun 4, 2010)

That is a pretty sweet thread. 

No one has anything to say on these guys? My last thread was everyone telling me to switch over to them.


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## kingfisherfleshy (Jun 4, 2010)

Anybody?


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## HolyAngel (Oct 18, 2010)

Yeah I don't know anything about them sadly but I want to.. Ive been debating on them for my 5gallon but without par numbers or any info, I don't want to spend the cash quite yet.


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## audioaficionado (Apr 19, 2011)

Hoppy has a formula (spread sheet usable I think) that might be able to answer our specific questions. Since he isn't answering our specific threads on PAR38/30 LED bulbs, maybe he want's us to at least try and calculate based on the total 1W/3W LEDs, element spacing, angle of divergence and distance from substrate.

Our formula might be easier as all the LEDs on a bulb should be superimposed into one cone of light. If we can figure out the cone angle/spot size for a given distance to substrate and convert the specified lumens to approximate PAR it should be easy-peasy. Just figure out how many bulbs on a track to produce slightly overlapping illumination cones that you'll need for a given length of a tank.

I think the general rule is to overbuild and then dim to suit.


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## kingfisherfleshy (Jun 4, 2010)

Sorry havent been on in awhile, thanks again audio. 

There are dimable ones on [Ebay Link Removed] they cost like $60 a piece. That is probably what I will have to end up getting though it looks like.


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## Hoppy (Dec 24, 2005)

By far the best way to evaluate those PAR38/30 LED lights is to get one and measure the PAR it produces at various distances, plus how much light spread you get. I don't think the equation I worked up will work for that type of LED configuration.


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## audioaficionado (Apr 19, 2011)

In a way it will. We'd just figure the spread angle of a single element and multiply it by the # of LEDs. Spacing would be zero and no additional rows. Should be a simple equation that will require someone with PAR meter access to buy a few of the 7W to 21W bulbs w/1W and/or 3W LEDs and experiment.

Hoppy, has anyone figured out how to convert a standard light meter reading to 
a close approximation of PAR?


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## Hoppy (Dec 24, 2005)

audioaficionado said:


> In a way it will. We'd just figure the spread angle of a single element and multiply it by the # of LEDs. Spacing would be zero and no additional rows. Should be a simple equation that will require someone with PAR meter access to buy a few of the 7W to 21W bulbs w/1W and/or 3W LEDs and experiment.
> 
> Hoppy, has anyone figured out how to convert a standard light meter reading to
> a close approximation of PAR?


Light meters are weighted to match human eye sensitivity. But, PAR is based on the light that plants can use. You could find a conversion factor for any one bulb, but a different bulb, with a different spectrum of light would need a different conversion factor. I think if we limit ourselves to just the various white light LEDs such a conversion factor will be accurate enough for all of them. But, not having such a meter I haven't played with doing that.


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## kingfisherfleshy (Jun 4, 2010)

I like how everyone mobs my last thread telling me to use these, and now, nothing. 

I cant believe that no one has experience with these fixtures. 

Seems kinda pricey for me if Im going into it blind.


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## Jeffww (Aug 6, 2010)

I was going to get one of the par38 bulbs for a nano reef but I'm also wondering whether or not they put out enough PAR. I'm planning on some sps too. I mean 17watt LED light seems like plenty of penetration but I guess we'll see.


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## kingfisherfleshy (Jun 4, 2010)

I have a friend that is using the same brand of PAR38 that I am looking at using on his reef. His comes with blue leds, the one I would use on the planted does not. 

Both are dimmable though.


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## Jeffww (Aug 6, 2010)

How big is his reef tank? Does he have any sps?


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## mulm (Jun 3, 2010)

audioaficionado said:


> ...
> 
> 
> 
> ...


This is my build. I would be glad to take PAR readings if anyone has a meter. Deposit...shipping...just let me know. I am curious too.


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## Jeffww (Aug 6, 2010)

100% sure you can ask a reef club in florida to borrow a par meter. they're big on fancy gadgets reefers are.


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## audioaficionado (Apr 19, 2011)

I'm starting to see 5000 K bulbs in Lowe's now and the price is starting to come down. I'd like to plug one in and measure the spread angle. Perhaps I can talk a store customer assistant to allow me to try a few out in store. I'm holding out for some 6500 K bulbs and have the cash to buy one if I like what I see. Until then I'm not wasting his time.

Looking for a small desktop LED lamp to use with my shrimp bowl project showed me that published specs mean nothing. The lamps I thought looked great on paper were not as good as the dirt cheap 2.1W lamp I eventually got at Staples. The difference was that the lower powered lamp had much better focus and a narrow beam angle to project more light at my substrate.

I bet there is a large difference in useful beam size between different brands and models in PAR3x bulbs even if they have the same paper specs. They also come as flood or spot lights and many boxes don't say which one either.


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## Jeffww (Aug 6, 2010)

I'm sorry what? We're talking about PAR her. Spread is inconsequential if you have sufficient PAR. Plus this bulbs were made for our hobby. the PAR38 bulbs were originally made as a high penetration reef lighting unit. We aren't comparing CFL's or cheapo 2 watt LEDs of unknown PAR. We're looking at a 120 dollar piece of equipment and real numbers showing how good they are at making living things stay alive. Not how bright they are.


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## audioaficionado (Apr 19, 2011)

No way I'm looking at any $120 reef bulbs. I want bang for the buck and that ain't it. My 2.1W lamp was just an example of the lack of meaningful published specs at least for our purposes of planted aquariums. This is a discussion, not an argument


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## scapegoat (Jun 3, 2010)

mulm said:


> This is my build. I would be glad to take PAR readings if anyone has a meter. Deposit...shipping...just let me know. I am curious too.


how is growth?

i see those LED lamps at Lowes and i'm tempted to pick one up for my 20l


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## yikesjason (Jul 2, 2008)

I am glad someone finally took the plunge and got some of these LEDs. I want to do the same with my planned 34 gal mr aqua set up, but I am hesitant to get the LEDs because of lack of history and info. I was even looking at the 5,000k bulbs at HomeDepot the other day and narrowly escaped convincing my self to buy them then and there.


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## mulm (Jun 3, 2010)

The lamps I am using are not from Lowes/Home Depot. They are CREE XRE based from ledliquidatorsinc.com. I cannot speek for the hardware store versions...but these have been great for me. I used two 21w PAR30s on a 24"x15"x17" tank and had crazy growth (L. aromatica, P. stellatus, R. wallichii, etc)...but I suspect still light limited (as desired). 

Currently I am using 2 36w PAR38s on a 48"x18"x18" tank roughly 30" off the substrate. It is too new to tell for sure, but I suspect it is light limited as well. The setup is very pleasing to my eye. I may add a 21w to the set up at some point in the future if I decide to add more demanding plants. For now, it looks great...and the crypts and ferns probably wont need any more.


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## scapegoat (Jun 3, 2010)

it seems like two of those would be too much for my 20l... but one probably doesnt have the necessary spread required from 4-6" off. i may see about two of the weaker ones and see what i can do


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## Hoppy (Dec 24, 2005)

mulm said:


> The lamps I am using are not from Lowes/Home Depot. They are CREE XRE based from ledliquidatorsinc.com. I cannot speek for the hardware store versions...but these have been great for me. I used two 21w PAR30s on a 24"x15"x17" tank and had crazy growth (L. aromatica, P. stellatus, R. wallichii, etc)...but I suspect *still light limited* (as desired).
> 
> Currently I am using 2 36w PAR38s on a 48"x18"x18" tank roughly 30" off the substrate. It is too new to tell for sure, but I suspect it *is light limited* as well. The setup is very pleasing to my eye. I may add a 21w to the set up at some point in the future if I decide to add more demanding plants. For now, it looks great...and the crypts and ferns probably wont need any more.


The goal for a planted tank is to have the plants growth rate limited by the amount of light available to them. We don't want the growth rate to be limited by nutrients or CO2, just by light. I think that is what you are saying, and, if so, I agree with it.


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## mulm (Jun 3, 2010)

Hoppy said:


> The goal for a planted tank is to have the plants growth rate limited by the amount of light available to them. We don't want the growth rate to be limited by nutrients or CO2, just by light. I think that is what you are saying, and, if so, I agree with it.


Yep. My goal is primarily aesthetic... and to provide just enough light to maintain slow growth and minimal fluctuation in nutrient demand. Long term that should result in fewer battles.


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## kingfisherfleshy (Jun 4, 2010)

Jeffww said:


> How big is his reef tank? Does he have any sps?


Its a 2g but he has it dimmed down quite a bit.

He is starting to try sps. 

Looks like this is finally picking up...so what do I need to do to run some of these on a 10g?

What am I looking at getting?

Fertz? Co2? (Other than DIY?)

Thanks


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## Sharkfood (May 2, 2010)

Has anyone measured these things yet?


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## kingfisherfleshy (Jun 4, 2010)

Bump?


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## IWANNAGOFAST (Jan 14, 2008)

I picked up 2 of the rapidled par38 bulbs and I'll test the PAR. however, these are reef models so there's a lot of blue light on them. 

The thing with these bulbs is that "par38" just means bulb size, PAR levels can depend on optics, what kind of LEDs are used, how many, etc etc.

I've seen par38 bulbs with only 5 LEDs whereas others have like, 11 LEDs on them. Brand to brand it's hard to tell, and unless people are willing to spend the money to buy them and test them out, we're never going to know.


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## kingfisherfleshy (Jun 4, 2010)

Thanks...let me know what happens.


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## Sharkfood (May 2, 2010)

Just looking around at different bulbs and comparing their intensities in Lumens, the cool white CREE based 12W spotlights seem to be putting out the most light about 1200 Lumens. 

That's a pretty serious amount of light from such a small bulb, considering a typical 48" T5HO bulb is putting out 5,000 lumens. I believe this is spread out along the length of the tube, since shorter bulbs are listed with lower lumen output. 1200 Lumens from a single point is impressive to say the least. 

Cheapest I can find them online is about $40-$50 each.

Since they are to some extent directional, you could provide different light levels to different areas of the tank (You could blast light at your red stems without frying your moss.), and less spread would make it easier to keep light from striking the glass high in the tank where GDA likes to lurk. You could also cluster them to increase intensity fairly easily or angle them to get light past hardscape.

I've been on pins and needles for weeks waiting for someone to post measurements of these things.


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## kingfisherfleshy (Jun 4, 2010)

How much for a 10g tank? I have seen one of these...and it looks like the sides of the tank are in the shade...two units is seeming like overkill however.


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## 2in10 (Feb 8, 2011)

The Par38 bulbs using 3W LEDs are the strongest and best for penetration depending on the optics. 40 degree optics can penetrate up to 48" of water with medium PAR per Hoppy's table. Most come with 60 to 80 degree optics and penetrate very well. Cool white LEDs have a Kelvin temperature of around 6500K. I am certain you can get RapidLed to put one together with cool white LEDs only. Thay have been quite responsive to requests from the reef forum I am on.


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## 2in10 (Feb 8, 2011)

OrphekUSA and RapidLED have PAR30 and PAR38 bulbs. Rapid's PAR30 has 5 diodes and the PAR38 has 7 diodes. Orphek's PAR38 has 11 diodes. 

Check out their sites for more information. I think Orphek may have PAR data on it IIRC.


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## IWANNAGOFAST (Jan 14, 2008)

rapid no longer makes par30 bulbs, and their par38 bulbs are more like 14k in color


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## 2in10 (Feb 8, 2011)

IWANNAGOFAST said:


> rapid no longer makes par30 bulbs, and their par38 bulbs are more like 14k in color


I believe you can contact Rapid and they will build one using all white diodes for you.


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## speedie408 (Jan 15, 2009)

I think I'll get these: http://flbs.us/index.php?page=shop....id=54&vmcchk=1&option=com_virtuemart&Itemid=2

Unless someone else offers something equivalent or better? Best price I've seen so far after 30mins of Googling.


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## gnod (Mar 24, 2011)

"The F.L.B.S PAR38 is equivalent to a 250 watt (21.5watt) or 250 watt incandescent bulb" wowsers! that sounds like a lot of light.. any idea what this would be in terms of T5 lighting? like how many strips or watts? just curiously thinking outloud


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## 2in10 (Feb 8, 2011)

gnod said:


> "The F.L.B.S PAR38 is equivalent to a 250 watt (21.5watt) or 250 watt incandescent bulb" wowsers! that sounds like a lot of light.. any idea what this would be in terms of T5 lighting? like how many strips or watts? just curiously thinking outloud


About 4 bulbs worth I think, 96 watts.


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## WingoAgency (Jan 10, 2006)

This is a chart of the 15x1W 6,700K, 60 degree. 
http://www.flickr.com/photos/[email protected]/6047800527/in/set-721576260547715112W


Next week, I will chart a 5x2W, and may be also the 3x2W 6,700K 60 degree. Stayed tuned.


I think a 15x1W will be over kill for a 10G. Use 2 pcs 3x2W (the one to the right)
http://www.flickr.com/photos/[email protected]/5805805342/in/set-72157626054771511


How to post pic, please? I cannot get it to work.


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## speedie408 (Jan 15, 2009)

Here you go...


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## kingfisherfleshy (Jun 4, 2010)

What sort of par do you want in a mixed lighting setting? I dont have anything that takes up too much light, but want more because Im switching to dosing, and pressurized co2 if I do this...I also grow floaters, so light penetration is affected by that. 

Glad to see that we finally have some meat on the subject ha


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## IWANNAGOFAST (Jan 14, 2008)

You'd want to shoot for 40-50umols of par, and you can grow anything with that. 

These par bulbs are pretty nifty. Unfortunately, rapidled doesn't make custom ones anymore, I contacted them to see if they could make an all royal blue one for my reef but Mike said they can't anymore.


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## 2in10 (Feb 8, 2011)

IWANNAGOFAST said:


> You'd want to shoot for 40-50umols of par, and you can grow anything with that.
> 
> These par bulbs are pretty nifty. Unfortunately, rapidled doesn't make custom ones anymore, I contacted them to see if they could make an all royal blue one for my reef but Mike said they can't anymore.


Well that is a royal bummer.


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## IWANNAGOFAST (Jan 14, 2008)

yeah for reals. oh well, the rest of their line is top notch so I'll still order through them for any DIY stuff.


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## speedie408 (Jan 15, 2009)

LED EXPERTS,

Would these be good just as fill in lights? Or would they be too weak? What's your opinions? http://www.superbrightleds.com/cgi-...ategory=MR16&Page2Disp=/specs/PAR30D-W7X1.htm









I know they're only 1W LEDs and not the 3W ones.


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## audioaficionado (Apr 19, 2011)

speedie408 said:


> LED EXPERTS,
> 
> Would these be good just as fill in lights? Or would they be too weak? What's your opinions? http://www.superbrightleds.com/cgi-...ategory=MR16&Page2Disp=/specs/PAR30D-W7X1.htm
> I know they're only 1W LEDs and not the 3W ones.


It would make a good spot light to highlight an area, but for less than twice the price you can get thrice the light levels with 7x3W bulbs.


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## speedie408 (Jan 15, 2009)

audioaficionado said:


> It would make a good spot light to highlight an area, but for less than twice the price you can get thrice the light levels with 7x3W bulbs.


Are you referring to the F.L.B.S PAR3s?


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## audioaficionado (Apr 19, 2011)

Dimmable par38 6500K LED search.

All kinds of selections for dimmable LED PARxx bulbs.

http://www.ledliquidatorsinc.com/cat-dim.php

http://www.ledliquidatorsinc.com/PAR30-LED-Dimmable-21-Watt-Cree.php


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## Sharkfood (May 2, 2010)

It seems like the best output comes out of the 12x1W leds at over 1000 lumens. The 27W only puts out slightly more at about 1200. Being the same price I suppose it's better to go with the 1200 lumen light, but I wonder if there's a big difference in heat or bulb life?

I realise that worrying about LED bulb life is probably idiotic.

I really don't have any experience with LEDs. It seems like I should be able to easily add lights to a tank over time with these lights as they simply screw into a regular edison base.

Still, at 70-90 dollars a piece it would take about $300-$400 to get the light output of a 48" T5HO bulb. (Though the light would be more concentrated.)

I won't be buying lights for my next project for a couple of months likely, so hopefully the next generation will be out by then and they will either put out more light, or cause the current bulbs to be cheaper.


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## audioaficionado (Apr 19, 2011)

Another thing to consider: How many T5HO lights can be dimmed? Sometimes raising your light fixture isn't an option.


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## dknydiep1 (May 21, 2006)

Just FYI, Rapidled makes an all white 6500 bulb now. Someone test it!


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## WingoAgency (Jan 10, 2006)

dknydiep1 said:


> Just FYI, Rapidled makes an all white 6500 bulb now. Someone test it!


I have test 6,700K PAR38 before, of course before Rapidled is selling theirs, here is the par chart








[/url] Flickr 上 WingoAgency 的 PAR38 15x1W WingoLED DayLight 6,700K PAR DATA[/IMG]


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## audioaficionado (Apr 19, 2011)

Looks like there is a hot spot in the center.


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## WingoAgency (Jan 10, 2006)

audioaficionado said:


> Looks like there is a hot spot in the center.



Correct, all LEDs when cluster together will create a hot spot so is all fixtures with even distribution. Unless the fixture is shape convex(I am thinking of making an engineering sample) or use reflector for a reverse mount(so far only one company made this), this phenomenon is unavoidable.

With 60 degree lens the somewhat optimal placement would be about 30-36" from bottom 15"-12" apart, for more even spread.


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## audioaficionado (Apr 19, 2011)

I was thinking of going with these PAR30/38 dimmable LED lamps, but with that hot spot issue, DIY with individual LEDs on a extruded heatsink should give more even results.


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## DogFish (Jul 16, 2011)

I've just run my wiring, installed the dimmer, hung the track light pendants. From doing that I'd tell you want dimmable. Especially at this point in the hobby as it's pretty clear we collectively really don't fully understand these bulbs for plant use ...YET.

There are not many out of the box options to hang these lights. I was able to pc. a "kit" together from Home Depot. I am speaking in terms of equipment that goods good enough for a display tank, not some industrial, steam punk, retro Frankinsten's lab fixture.


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## WingoAgency (Jan 10, 2006)

audioaficionado said:


> I was thinking of going with these PAR30/38 dimmable LED lamps, but with that hot spot issue, DIY with individual LEDs on a extruded heatsink should give more even results.



Actually the the difference is little if you place the par bulbs carefully. Remember you are not putting just one bulb in most deployment.

I did an experiment with the even spread of the DIY style and the cluster style and measured them years back, the results were not very different. There is actually one guy who did an actual writeup with measurements some where, either in this forum or in reefcentral, that clustering and none clustering of the LEDs have very little effect in the how even the lights are, the optics play the much more importance in this aspect.

Try to impose two bulbs' value over the other at 12" apart and sum the value of the yellowish orange number, you will get almost all similar summed par values.


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## WingoAgency (Jan 10, 2006)

Comment withdrawn


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## DogFish (Jul 16, 2011)

I found this in an ad for PAR38 bulbs:

Notes on dimmers:

All of our dimmable LED light bulbs are tested and compatible with many dimmers. However, they are not 100% compatible.

Using only single light bulb sometimes will cause flickering with some of the dimmers. To avoid this problem, and in order to achieve the best performance, we request our customers to install a minimum of two LED light bulbs per dimmer. The typical dimmer normally has 600W of power and requests a minimum of 60W of power used in order to be stabilized, with less than this power usage, it is under loading condition and is not the original dimmer designed for. Single LED light bulbs are hardly over 20W, so if the user can install minimum of 4 LED light bulb, the performance will yield a visible difference.

Home Depot has a Dimmer for LED lights, I installed that for mine. 

I ordered my bulbs from e bay "PAR38 LED CREE 18W WHITE FULLY DIMMABLE Light Bulb E26" They should be here Friday, I'll follow-up after I install.


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## DogFish (Jul 16, 2011)

Got my bulbs today, PAR38 LED CREE 18W 5500K DIMMABLE 12LEDS, 30degree lens.

The the lights are 26" above the Aquarium stand, PAR38 vs. 60watt bulb for comparison, in a dark room. Need to find another lamp shade :wink:


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## DogFish (Jul 16, 2011)

Found another source EagleLight LEDs 

ttp://www.eaglelight.com/product/PAR38-E27-11W9-DIM/Dimmable-11W-PAR38-LED-Spot-Light.html


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