LED Array for 15" x 10" Scrubber - Picture Attached, Help Please

[Black Widow]

I have come up with a diagram for a possible LED Array which I am going to build with parts sourced from RapidLED.com, I would like suggestions on this design and whether you think it will light 15 x 10 Scrubber screen well enough or not?



Each unit will light one side of the scrubber so I am building 2 of these.

[Black Widow]

So Santamonica and floyd any ideas! Would this work?

[Floyd R Turbo]

Blues will have to be run at 1/2 power. Otherwise, should be fine.

[Black Widow]

why half power?

[Floyd R Turbo]

most of my Rev 1 L2's had 6 reds in a 2" O.C. rectangle pattern with a single blue in the center. All of them ended up with screens that took forever to fill in at the middle. I thought it was because there were 2 reds on either side of a blue (1" apart each) but that wasn't the whole story.

Far end LEDs (420nm violet and 660nm red) have a lower radiometric flux output, essentially they are less intense than the next LED towards the middle of the visual spectrum - this would be 440nm blue and 620nm red. Those are multiple times as intense. 440-450nm blue has plenty of spectrum to hit both the Chlorophyll A & B blue peaks, but the flux output is very high and it photoinhibits growth. It will likely eventually fill in, but I still instruct Rev 1 users to put black tape over the diffuser right in front of the blue LED to knock down the intensity.

For Rev 2, I use 2 blues and wire them in parallel within the series string (like a current divider), and this significantly reduced screen burning. Most people do not have it at all, it's only the tanks that have low nutrients to start with that show signs of lower growth center.

The bottom line is that after having over 100 units in the field, I have determined that LEDs can be too intense if you don't arrange them properly.

Also I would not get them from Rapid. I would get them from Steve's, he is a distributor and selects only specific bins, and they are optimal for what we do, and they cost less. Their 660s are all identical and more importantly, the RBs are 440-450 (deep blue) and are all very well matched (same bin). He also carries a good deep violet. But IMO you don't need it. Rapid is 2nd in my book, because you do not have specific bin selection. Because they are a retailer and not a distributor, in order to keep their prices down, you get more of a random mixture of bin selection. Not as bad as the knock-off LEDs like LEDgroupbuy ("exotic" = "grab bag junk") or even worse the chinese and e-bay knock offs. But why not pay $0.10 less per LED at Steve's and get better ones. Kind of a no brainer.

[Black Widow]

most of my Rev 1 L2's had 6 reds in a 2" O.C. rectangle pattern with a single blue in the center. All of them ended up with screens that took forever to fill in at the middle. I thought it was because there were 2 reds on either side of a blue (1" apart each) but that wasn't the whole story.

Far end LEDs (420nm violet and 660nm red) have a lower radiometric flux output, essentially they are less intense than the next LED towards the middle of the visual spectrum - this would be 440nm blue and 620nm red. Those are multiple times as intense. 440-450nm blue has plenty of spectrum to hit both the Chlorophyll A & B blue peaks, but the flux output is very high and it photoinhibits growth. It will likely eventually fill in, but I still instruct Rev 1 users to put black tape over the diffuser right in front of the blue LED to knock down the intensity.

For Rev 2, I use 2 blues and wire them in parallel within the series string (like a current divider), and this significantly reduced screen burning. Most people do not have it at all, it's only the tanks that have low nutrients to start with that show signs of lower growth center.

The bottom line is that after having over 100 units in the field, I have determined that LEDs can be too intense if you don't arrange them properly.

Also I would not get them from Rapid. I would get them from Steve's, he is a distributor and selects only specific bins, and they are optimal for what we do, and they cost less. Their 660s are all identical and more importantly, the RBs are 440-450 (deep blue) and are all very well matched (same bin). He also carries a good deep violet. But IMO you don't need it. Rapid is 2nd in my book, because you do not have specific bin selection. Because they are a retailer and not a distributor, in order to keep their prices down, you get more of a random mixture of bin selection. Not as bad as the knock-off LEDs like LEDgroupbuy ("exotic" = "grab bag junk") or even worse the chinese and e-bay knock offs. But why not pay $0.10 less per LED at Steve's and get better ones. Kind of a no brainer.

I understood most of what you said including about series strings / current dividers but you have to understand I am still an LED Newb so I dont know what a BIN is? So when you say half power the Blues you mean put them in there own parallel circuit? or put em on a dimmer?

Also if Deep Red is significantly weaker than the Peak at Royal Blue but 620nm Red is quite powerful would it not be better to replace all the deep reds with 620nm reds so that all the reds will match the royals blues in intensity/flux?

I only suggested RapidLED as my source as they are a Sponsor on a another forum and they ship to UK, who is Steve / Website? Will he ship over the Pond so to speak?

Thanks Turbo for your help so far

ps you dont have remind me that you have a 100 scrubbers / units on the market, we all know you are scrubber king

[Floyd R Turbo]

Here is my L4 fixture



Closeup of one half



closeup of the blues



Pic of the fixture running. Notice how the blues to not take over in the photo, the output looks about the same as the reds

[Floyd R Turbo]

Oh yeah on binning. Binning is a sorting method. After the LEDs all are produced, they test them at various power levels to determine what their dominant bandwidth, voltage drop, intensity, etc are. Distribution is like a bell curve, so you will have some that are really poor emitters, and some that are really exceptional, and of course, most of them right in the middle. They separate out all of the emitters into "bins" and then you can select exactly which one you want.

Most companies (like Rapid) don't tell you what bin you are getting because they just get whatever is the right price point for the quality they wish to provide. They will get you specific bins if you want them, usually, for extra.

Steve's lists the exact bin that he gets, every time. They are the best bin, highest output. Always. You get what you pay for.

[Black Widow]

StevesLEDS Heatsinks suck, he only has Aluminium Tubes I need Heatsink plates. Does he do the traditional LED Heatsinks ?

[Floyd R Turbo]

Not as far as I know. I haven't used his aluminum tubes, but I know that they are made to be used in conjunction with those little fans he sells.

Rapid sells extruded heat sinks, as well as HeatsinkUSA, or you can just get them from MakersLED.