LED lighting and PAR measurements -- Advice?

pdelcast · 07/26/2008, 11:07 PM

Just FINALLY completed my DIY LED setup for my new 300 gallon tank. The setup uses about 1150 watts of LEDs (384 x 3 watts), in a 66% blue (450nm), 33% 12000K white (470nm pump, triple phosphor) combination.

Tank measurements are 96" x 24" x 31" high

PAR measurements were done with an Apogee Instruments SQ-110 Quantum sensor connected to a Fluke 83 III digital multimeter.

Measurements were:

Above water surface (2.5" from LEDs): 3250 PAR
Just below water surface(4" from LEDs): 2200 PAR
5" below water surface (6.5" from LEDs): 1700 PAR
At top of rock shelf (about 17" deep) : 875 PAR
At surface of sand (about 28" deep) : 450 PAR

All PAR measurements are in umol m-2 s-1

So, higher than sunlight intensity just under the water surface, and still very bright at the top of the sand.

QUESTION -- Did I go too far? Will I bleach everything I put in the tank?

Pictures follow:
Apogee Sensor :

This thing is SO BRIGHT it washes out all the other lights in the room:

Edge on : 110 degree beam pattern visible in the murky water (new tank)

LEDs reflecting off top of the water: (Note the fans, ballasts, and heat sinks)

Whole tank shot: -- NOTE all lights are on in the room -- the camera had to back the lighting down

Chris Lakies · 07/27/2008, 12:04 AM

wow wish i could afford one of those!

Yea those are awesome par readings!

you DIY'd that sucker?!

I wonder can it be dimmed?

That way you can ramp it up slowly.

pdelcast · 07/27/2008, 12:07 AM

Quote:

Originally posted by Chris Lakies
wow wish i could afford one of those!

Yea those are awesome par readings!

isn't it dimmable?

I think I'm gonna have to go back and make it dimmable now. I'll have to replace the ballast control resistor with a pot --

But there are 16 ballasts (each running 24 LEDs) -- so that's a lot of soldering.

I did DIY this sucker.

Here is the original thread where I discussed the creation of the LED boards:

http://reefcentral.com/forums/showth...readid=1418787

Gomer · 07/27/2008, 12:18 AM

which emitters/drivers did you use? Nice to see more LED projects!

pdelcast · 07/27/2008, 12:41 AM

Quote:

Originally posted by Gomer
which emitters/drivers did you use? Nice to see more LED projects!

These are Cree XRE emitters - Royal blue (450nm) and cool white (binned at 12000K color)

Driver was designed by me. Generates 950ma (current regulated) from 110/220V input, at up to about 90VDC output (so up to about 26-28 LEDs in series maximum.) In this application, each 24 LEDs are driven by a separate ballast -- and there are 16 ballasts total running the 384 emitters.

Picture of the LED boards (still in array form -- straight from the machines)

And here is a closeup showing the emitters: (Note the aluminum core circuit boards)

Philwd · 07/27/2008, 01:01 AM

384 Cree XRE LEDs. WOW!! That makes sense now. 48 per foot. That's double what PFO and AI have.

Sooo how much did this set you back?

pdelcast · 07/27/2008, 01:35 AM

Quote:

Originally posted by Philwd
384 Cree XRE LEDs. WOW!! That makes sense now. 48 per foot. That's double what PFO and AI have.

Sooo how much did this set you back?

A lot.

Had to buy a couple reels of each LED color, and buy qtys of the circuit boards (over $2K just for the boards.)

All in all, about $5K or so for the project -- but this is a prototype for a commercial product.

What I'm mostly worried about is bleaching everything I put in the tank with the amount of light -- I guess it's time to start trying some corals in there to see how they do.

pdelcast · 07/27/2008, 09:46 AM

bump

I really do need someone who knows about high lighting levels to chime in -- do I need to turn these lights down, or will corals adjust OK to the high light levels?

Thanx!

Philwd · 07/27/2008, 11:26 AM

Use window screen between the lights and corals to help acclimate. Put a coupe screens down and take one off each week.

pdelcast · 07/27/2008, 01:50 PM

Quote:

Originally posted by Philwd
Use window screen between the lights and corals to help acclimate. Put a coupe screens down and take one off each week.

Do that every time I add new corals? Or will 350-450 PAR (on the bottom) be OK for most corals, and then just keep moving them up the tank every week?

Thanx!

Doahh · 07/27/2008, 01:57 PM

I think starting at the bottom and moving them up would work...
So... How much to make me one of these for a tank 36wx30dx19h

Doahh · 07/27/2008, 02:02 PM

Rereading the thread I'd actually raise the lights to about 12" over the surface of the water...

pdelcast · 07/27/2008, 05:30 PM

Quote:

Originally posted by Doahh
Rereading the thread I'd actually raise the lights to about 12" over the surface of the water...

I agree -- I'm gonna raise it 8" (can't go higher -- will interfere with the hood I'm building.)

Fish'InMN · 07/27/2008, 05:33 PM

I'll third that motion, no pun intended. Raising the lights will give you a wider spread as well so you won't have the "spotlight" effect as seen in your side-view shot.

pdelcast · 07/27/2008, 05:35 PM

Quote:

Originally posted by Doahh
Rereading the thread I'd actually raise the lights to about 12" over the surface of the water...

I'm also thinking about removing 1/2 of the LEDs. After doing a PAR measurement on my 90 gallon (8 bulb T5HO fixture,) I'm afraid it might just be too much light. My 90 gallon only reads 600 PAR just under the lights...

Can anyone tell me if this is TOO MUCH light?

Thanx!

Philwd · 07/27/2008, 09:41 PM

Hahn's data on the AI which uses Seoul Semi LEDs(Cree die) showed on a per watt basis it was equivalent with a HQI Phx 14K 250W in a good reflector. Since the AI is roughly 1/3 the wattage total light is also roughly1/3. With your doubling you will come much closer. So IMO keep the extra LEDs and either raise the light or make the strip double wide and halve the LEDs/foot.

07/26/2008, 11:07 PM	#1
pdelcast Registered Member Join Date: Mar 2008 Location: Kansas Posts: 256	LED lighting and PAR measurements -- Advice? Just FINALLY completed my DIY LED setup for my new 300 gallon tank. The setup uses about 1150 watts of LEDs (384 x 3 watts), in a 66% blue (450nm), 33% 12000K white (470nm pump, triple phosphor) combination. Tank measurements are 96" x 24" x 31" high PAR measurements were done with an Apogee Instruments SQ-110 Quantum sensor connected to a Fluke 83 III digital multimeter. Measurements were: Above water surface (2.5" from LEDs): 3250 PAR Just below water surface(4" from LEDs): 2200 PAR 5" below water surface (6.5" from LEDs): 1700 PAR At top of rock shelf (about 17" deep) : 875 PAR At surface of sand (about 28" deep) : 450 PAR All PAR measurements are in umol m-2 s-1 So, higher than sunlight intensity just under the water surface, and still very bright at the top of the sand. QUESTION -- Did I go too far? Will I bleach everything I put in the tank? Pictures follow: Apogee Sensor : This thing is SO BRIGHT it washes out all the other lights in the room: Edge on : 110 degree beam pattern visible in the murky water (new tank) LEDs reflecting off top of the water: (Note the fans, ballasts, and heat sinks) Whole tank shot: -- NOTE all lights are on in the room -- the camera had to back the lighting down __________________ Patrick Current Tank Info: 90 gallon reef - Acans, Zoas, Acros, Montis == 300 gallon reef to be mostly SPS

07/27/2008, 12:04 AM	#2
Chris Lakies Registered Member Join Date: Feb 2003 Location: Grand Blanc Michigan Posts: 1,446	wow wish i could afford one of those! Yea those are awesome par readings! you DIY'd that sucker?! I wonder can it be dimmed? That way you can ramp it up slowly. __________________ CL Current Tank Info: 50 breeder, 2 x XR15w pro (G4), 1 x MP40wQD, Apex JR, Ehiem-Jager 200 watt heater, Jabao DC6000 return, Reef Octo 150 elite SSS skimmer

07/27/2008, 12:18 AM	#4
Gomer Registered Member Join Date: Dec 2003 Location: SF Posts: 1,049	which emitters/drivers did you use? Nice to see more LED projects! __________________ -Tony

07/27/2008, 09:46 AM	#8
pdelcast Registered Member Join Date: Mar 2008 Location: Kansas Posts: 256	bump I really do need someone who knows about high lighting levels to chime in -- do I need to turn these lights down, or will corals adjust OK to the high light levels? Thanx! __________________ Patrick Current Tank Info: 90 gallon reef - Acans, Zoas, Acros, Montis == 300 gallon reef to be mostly SPS

07/27/2008, 01:57 PM	#11
Doahh Registered Member Join Date: Apr 2007 Location: Loomis CA Posts: 2,398	I think starting at the bottom and moving them up would work... So... How much to make me one of these for a tank 36wx30dx19h __________________ -Josh Current Tank Info: 90 Gal Custom SW Reef

07/27/2008, 01:01 AM	#6
Philwd Premium Member Join Date: May 2004 Location: Gilbert, Az Posts: 4,057	384 Cree XRE LEDs. WOW!! That makes sense now. 48 per foot. That's double what PFO and AI have. Sooo how much did this set you back?

07/27/2008, 11:26 AM	#9
Philwd Premium Member Join Date: May 2004 Location: Gilbert, Az Posts: 4,057	Use window screen between the lights and corals to help acclimate. Put a coupe screens down and take one off each week.

07/27/2008, 02:02 PM	#12
Doahh Registered Member Join Date: Apr 2007 Location: Loomis CA Posts: 2,398	Rereading the thread I'd actually raise the lights to about 12" over the surface of the water... __________________ -Josh Current Tank Info: 90 Gal Custom SW Reef

07/27/2008, 05:33 PM	#14
Fish'InMN Premium Member Join Date: Dec 2005 Location: MN Posts: 398	I'll third that motion, no pun intended. Raising the lights will give you a wider spread as well so you won't have the "spotlight" effect as seen in your side-view shot.

07/27/2008, 09:41 PM	#16
Philwd Premium Member Join Date: May 2004 Location: Gilbert, Az Posts: 4,057	Hahn's data on the AI which uses Seoul Semi LEDs(Cree die) showed on a per watt basis it was equivalent with a HQI Phx 14K 250W in a good reflector. Since the AI is roughly 1/3 the wattage total light is also roughly1/3. With your doubling you will come much closer. So IMO keep the extra LEDs and either raise the light or make the strip double wide and halve the LEDs/foot.