Can I combine a blurple with a 5000k LED for flowering?

chamenon

Member
I've scored some hyper tough shop LEDs. 45w at $8 a piece, 180 w in total. I'm planning to use one of these for the mother plant and use the remaining 3 for vegetating and flowering 3 clones cut from the mother. For this I was planning to buy a proper full spectrum grow light and use 2-3 of these shop lights as side corner supplemental lights.

But looking at grow lights, they are practically a combination of 2700K-5000K white LEDs and some red LEDs around 660nm with some blue LEDs. So I'm thinking since I've bunch of 5000K LEDs already, what if I add a 20-40w blurple in order to just enhance my 5000K lights' spectrum for flowering?

I'm aware that a proper grow light is more convenient but my starting costs for my grow tent is starting to add up and I'm trying to utilize what I've on hand for now and get the most amount of PAR for the money with the equipment on hand.

Looking at the distribution of light spectrum in various lights here is my calculation to justify my logic;

According to the chart I'm sharing below my white 5000K LEDs produces

0.8 part InfraR, 41 parts Red, 45 parts Green, 14 parts Blue, 0.15 parts UV

and a Blurple LED produces

1.4 IR, 75 R, 25 B an 0 UV,

therefore if I combine 135 watts of 5000K and 20w of Blurple, I should get a 155w LED with these ratios;

0.8 IR, 45 R, 39 G, 15 B, 0.13 UV which seems to an acceptable balance of RGB compared to Sun, HPS and other options like white and red lights.

Here is how I calculated;

1. Multiply the spectrum values of the 135-watt light by 135:
  • InfraRed (IR): 0.8 * 135 = 108
  • Red (R): 41 * 135 = 5535
  • Green (G): 45 * 135 = 6075
  • Blue (B): 14 * 135 = 1890
  • UltraViolet (UV): 0.15 * 135 = 20.25
2. Multiply the spectrum values of the 20-watt light by 20:
  • InfraRed (IR): 1.4 * 20 = 28
  • Red (R): 75 * 20 = 1500
  • Green (G): 0 * 20 = 0
  • Blue (B): 25 * 20 = 500
  • UltraViolet (UV): 0 * 20 = 0
3. Add the resulting spectrum values of the two lights:
  • InfraRed (IR): 108 + 28 = 136
  • Red (R): 5535 + 1500 = 7035
  • Green (G): 6075 + 0 = 6075
  • Blue (B): 1890 + 500 = 2390
  • UltraViolet (UV): 20.25 + 0 = 20.25
4. Divide the resulting spectrum values by the total power of the two lights (155 watts):
  • InfraRed (IR): 136 / 155 = 0.88
  • Red (R): 7035 / 155 = 45.39
  • Green (G): 6075 / 155 = 39.19
  • Blue (B): 2390 / 155 = 15.42
  • UltraViolet (UV): 20.25 / 155 = 0.13
So, the resulting spectrum when these two lights are combined would be

0.88 IR, 45.39 R, 39.19 G, 15.42 B, and 0.13 UV.

I can also add another 20w Blurple to have 175 watts at the following light ratios;

0.94 IR, 48.77 R, 34.71 G, 16.51 B, and 0.12 UV.

This assumes 20w Blurple will produce equal amounts of red and blue (but I primarely care about the RED part since 5000K LED should have enough blue in it already)

So my question is; are my assumptions wrong? Am I missing anything in this comparison? (One thing that I'd be missing is 2700K LEDs but I think the amount of red LEDs in the blurple light should make up for the lack of them, also I can always throw a 30w 2700K LED in there for $6 if needed)

These are the blurples I'm considering;


Sure, I can get a UNIT FARM grow light for a little bit more at $30 but this won't give me enough REDs, I would be just buying more white light with the grow light tax added.

To reiterate my point, I'm not trying to have a blurple grow setup, I understand why they are not optimum, I'm just trying to enhance my 5000K for flowering with the addition of some blurple lights for spectrum coverage.

Looking forward for inputs, suggestions, and inevitable roasting for wanting to use Great Value grow lights. :) Also looking for any other blurple LED recommendations.

Or is this a terrible plan and should I bite the bullet and get a 100-150w ViparSpectra and try to save money somewhere else?

ss.png
 
Last edited:

Drop That Sound

Well-Known Member
I just get 4 packs of 14-15 actual watt LED bulbs at walmart for around 8-15 bucks, daylight or soft white variety. They are cheaper in store for some reason, but I have scored deals on their site during clearances... Anyway, my point is.. Just one of the cheap single 100w equivalent screw in great value LED bulbs (with the plastic diffuser globe removed) puts out as much if not more light than that $30 20w tube fixture... The price per watt just doesn't make it worthwhile IMO. Just saying..



EDIT: NM, I see. You said you get the 30 dollar lights for 6? I would still buy a pack of screw in bulbs instead, and get 60w total, and rig up my own fixture, with one of these or something...
^ found these for $10 on their site, but only 13actual watts each..


How much you pay for screw in bulbs? ;)
 
Last edited:

chamenon

Member
I just get 4 packs of 14-15 actual watt LED bulbs at walmart for around 8-15 bucks, daylight or soft white variety. They are cheaper in store for some reason, but I have scored deals on their site during clearances... Anyway, my point is.. Just one of the cheap single 100w equivalent screw in great value LED bulbs (with the plastic diffuser globe removed) puts out as much if not more light than that $30 20w tube fixture... The price per watt just doesn't make it worthwhile IMO. Just saying..



EDIT: NM, I see. You said you get the 30 dollar lights for 6? I would still buy a pack of screw in bulbs instead, and get 60w total, and rig up my own fixture, with one of these or something...
^ found these for $10 on their site, but only 13actual watts each..


How much you pay for screw in bulbs? ;)
Thanks for the response, I totally agree, this is why I'm using the 5000K shop lights as the base for my light setup. At $8 a piece, I got 135watts (real not equivalent) of 5000K light for $24 and I can probably add more as more deals come up. Also since they are multiple pieces, I can have a dimming action going as well (I can light 1-3 LEDs individually). Here is the actual link to the light itself;


My worry is the ability to flower using just 5000K LEDs due to lack of RED spectrum. So even though that 20w $30 grow light has the "grow light tax" embedded in the price, I'm trying to catch a balance between being cheap and getting optimal results at the end of the harvest. Have you flowered with only 5000K LEDs? I don't want to end up with fluffy and miniature buds. Ultimately, if there were enough RED spectrum in the 5000K or even at 2700K spectrum, current grow lights wouldn't have included the RED (660nm) LEDs in their grow lights, right?
 

chamenon

Member
I just get 4 packs of 14-15 actual watt LED bulbs at walmart for around 8-15 bucks, daylight or soft white variety. They are cheaper in store for some reason, but I have scored deals on their site during clearances... Anyway, my point is.. Just one of the cheap single 100w equivalent screw in great value LED bulbs (with the plastic diffuser globe removed) puts out as much if not more light than that $30 20w tube fixture... The price per watt just doesn't make it worthwhile IMO. Just saying..



EDIT: NM, I see. You said you get the 30 dollar lights for 6? I would still buy a pack of screw in bulbs instead, and get 60w total, and rig up my own fixture, with one of these or something...
^ found these for $10 on their site, but only 13actual watts each..


How much you pay for screw in bulbs? ;)
I have 9 of those 9 actual watts 2700K LEDs and I thought about utilizing them but ultimately getting enough sockets for them beats the purpose of being affordable. The $6 30w Great Value LED I was talking about is different than the $30 20w blurple great value LED though. The $6, 30w 2700K LED is a screw on type LED and it's sold as high lumen LED. Here is the link for it;


I'm thinking maybe sticking two of these 30 actual watt 2700K LEDs in addition to my current 5000K 135w setup and maybe one of those $30 20w blurple will get the every single part of the light spectrum. So in total it's going to be about 135watts of 5000K, 60watts of 2700K and 20watts of red and blue spectrum at the both ends of the PAR spectrum.

Here is the data for the blurple light;

IMG_6774 - Copy.jpg
 
Last edited:

Jjgrow420

Well-Known Member
Once I saw a notification from you I actually thought to myself "I just hijacked their growoff "
Meh. If it were more linear I might have said maybe next time but since we would all be running diff cuts the legitimacy is ... questionable? Still fun and gives an understanding of what could be though so I'm all for it. Truth be, I'm a bit curious to see the results myself
 
Top