PAR38 .06w x 168 LED Grow light Test

[Ace25]

I received 2 PAR38 'grow' bulbs (http://www.amazon.com/gp/product/B004BV3Q96/) in the mail today and swapped out my CFLs. On paper they sounded great for my application.. but as expected, what you see on paper is usually not the same in reality.

Problems I see right off the bat .. not bright at all, I think 1 3w 660nm LED is brighter than the entire bulb. Another thing is there is no way the red spectrum is 660nm like stated on the spec sheet. Even with something as bad as the human eye to test with I can tell there is way to much orange in the light. There is some pretty serious heat on the bulb itself, much more than what 10w of power should feel like, so I will put a Kill-a-Watt on it and test the wattage. So first impression, I had high hopes but now having used it I really don't have much confidence in it at all. I am replacing 2 42w 2700k CFLs and will continue using the LEDs just to see how they compare. At this point I would be happy with just getting the same growth, I no longer think these bulbs will produce any better results than the CFLs, but they will only use 1/4 the power. Time will tell and I will update as the weeks progress.

Here is a picture of what it looks like, the blue circle I drew on there to represent where the light is focused. Color is off because my camera makes red and blue LEDs appear almost white. It is a very tight/focused beam, much tighter than I want, so I am going to have to redo my ATS a little, which is something I should have done on day 1. I will make it about 2" shorter so I can fit it sideways in the sump instead of diagonal, center it, and then I can have the LEDs at each end of the sump. That should give me perfect coverage.

http://farm9.staticflickr.com/8216/8343248155_42143798ce_c.jpg

[Ace25]

Got the bulbs pulled away a little to get better coverage and did a PAR reading, I get 250-275 PAR on the screen @ 6" distance. In comparison, the T5 fixture used on the SM100 got 490 PAR @ 3", and my old 42w CFL bulbs got 390 PAR @ 3". So when you look at it in those terms and consider the spectrum, the LED light is putting out much more usable light.

[Floyd R Turbo]

Look like a similar lamp to the one posted in this thread

http://algaescrubber.net/forums/showthread.php?2491-New-led-bulbs

I would be concerned about using this. Not intense enough. At least your lamp shows the actual LED wattage of 0.06 per LED and admits it's only 10w

[Ace25]

A PAR meter measures the intensity of the spectrum between 400-700nm. The results above are from my PAR meter. Curious why you think they not intense enough when I posted the results showing they are? To me 275 PAR of red/blue light is much greater in 'photosynthetic' intensity than 390 PAR out of a 42w 2700k CFL where most of the spectral output is in the yellow and green bands. A red photon is no more or less intense out of a 10w LED as it is out of a .06w LED. Photons are a fixed wavelength/size, they don't act like balloons and store more intensity if you put a bigger light source behind it. Bigger lights just put out more photons with means higher PAR because more photons are hitting the sensor in a measured time frame, but my initial test seems to tell me there is plenty of photons/intensity and in a good spectrum so I do think the light will work, how well it will work is to be determined. I think it will be slightly better than the 42w CFL and use 1/4 the power, but not as good as my 3w setup (which uses about 30w), but I would like to be shown otherwise, that would be a pleasant surprise.

That other bulb.. not sure what the orange is about other than a waste. This bulb has a slight orange tint, but certainly not orange. Looks more like 630nm to me than 660nm, but I will take one into work tomorrow and get a true spectral reading to see what it really puts out.

The only reason I am testing these is because I got a Amazon gift card from work, so I spent it on these bulbs. I would not have bought them otherwise because I have all the parts to make a DIY light just a few feet away from me that I know would work great.

[kotlec]

Theory on photons vice power is what I was always thinking . Will be following your experiment with great interest.
Just look at Jaczals thread . He is using pink ribbon leds. I dont know what wattage individual leds has , but I thing way under 1W as it can be used with out heatsinking. Also nobody knows what spectrum it is on and how this pink light is made. Regardless of all that he is getting nice growth !

[Ace25]

Well, as expected, when put under a spectrometer the 2 peaks I see with this bulb are 462nm and 635nm. Not exactly the ideal spectrums for photosynthesis but close. I am more surprised how well I am starting to be able to look at a colored light and guess the spectrum. I think I have been staring at too many LEDs over the last few years, especially reds and blues.

I will update with results on Saturdays. I will clean tomorrow and then a week from tomorrow I will give my first impressions in comparison to the CFLs I was using.

[mess7777]

very interested to see the results here as I was about to run the same experiment on my ATS. I currently have 2 - 23 watt CFL bulbs. They certainly look cooler with that alien red purple tinge!

[Ace25]

So far my screen has just gotten a lot more green with these new lights. Before it was mostly that brown stuff and a lot of cyano on the screen with very weak algae when I used CFLs. Now it is bright green and stiff/stuck to the screen really well like my other LED scrubber.

So, initial results seem very positive, but it looks like it will take a few weeks to 'fill in' with green completely. I don't think these lights are 'ideal' by any means, but as far as a 'screw in bulb' goes to me it seems like one of the better options vs using the 12x 1w bulbs that are way to spotlighty.

[mess7777]

Why did you end on the one you chose. For example, this one is significantly less and looks similar.

http://www.amazon.com/LEDwholesalers-1313MX-PAR38-Power-Light/dp/B001NDRGNC/ref=pd_sbs_lg_4

Good advice on the 12x1w as that is what I was originally looking at.

[Ace25]

That one you linked to is in between what I bought and the 12w 1w LED light. That link has 30 RED 650nm + 12 Blue (450nm), where as mine has 168 LEDs, meaning less spot light/intensity and more even coverage. I still think mine is too spotlighty to put close to the screen, it seems 6" is the ideal distance on my setup which I know a lot of people don't have that much room on either side of the screen to mount lights, so I wouldn't recommend it for everyone. Looking at a picture of that bulb in your link not turned on it looks like it would also be very spotlighty because all the LEDs are packed tight in the center of the bulb. The Amazon picture is NOT a picture of the bulb for sale in the link, the picture below is what the bulb looks like.

http://www.sears.com/ledwholesalers-1313mx-11-watt-par38-blue-red-led-high/p-SPM6460230008P
http://c.shld.net/rpx/i/s/pi/mp/19845/6378369508p?src=http%3A%2F%2Fecx.images-amazon.com%2Fimages%2FI%2F21PZXWZ27eL.jpg&d=46d3d56fb563fc6adac0cddf45f5641f700393f9

[mess7777]

good stuff thanks. I think I'll go ahead and grab a couple, seems like they are going well enough for you and I'll get at least as good as CFL without having to do bulb changes