Lighting - using what you got

[Tony420]

I'm looking to discuss using lighting that I already have, not be told to go out and buy the newest LED grow lights (which I will probably do in the future anyway).

Here's what I have:
2 x 4 foot grow area.

4 - 4 foot long LED shop lights - 5000k (supposedly 9600 lumens each).
2 - 2 by 4 foot LED lights for a hanging ceiling (I was going to hang these vertically).
this yields a reading of 24,000 to 26,000 lux about a foot above the plants.

I know florescent light can be used in the veg stage fairly well, just not too cool for flowering. If these LED lights are equivalent to florescent and need more blue and red spectrum for flowering, could I place a gel or stained glass or some other material I have around over some of the lighting ( I was thinking one four footer with blue and one with red)?

 

[Mañ'O'Green]

I'm looking to discuss using lighting that I already have, not be told to go out and buy the newest LED grow lights (which I will probably do in the future anyway).

Here's what I have:
2 x 4 foot grow area.

4 - 4 foot long LED shop lights - 5000k (supposedly 9600 lumens each).
2 - 2 by 4 foot LED lights for a hanging ceiling (I was going to hang these vertically).
this yields a reading of 24,000 to 26,000 lux about a foot above the plants.

I know florescent light can be used in the veg stage fairly well, just not too cool for flowering. If these LED lights are equivalent to florescent and need more blue and red spectrum for flowering, could I place a gel or stained glass or some other material I have around over some of the lighting ( I was thinking one four footer with blue and one with red)?

@Tony420 welcome to AFN.

Blue Colored glass changes the color your eyes see by filtering out the other colors. It does not change the photons wave length. So the simple answer is no that won't help. The plants will just get less white, red or green light.

 

[Bruce Campbell]

Prof. Bugbee has some good videos explaining basic considerations for grow lighting - here's his youtube channel, and this video is a pretty good primer. (MIGRO's channel and website is also a very good source for reviews and info.)

26K lux with those lights should be somewhere between 300-400 PPFD - which is decent for germination and seedlings, but you'd normally want ~2x that for veg and ~3x that for flowering. Running 24 hrs a day for autoflowers, you would hit around 30 DLI, which is a decent value.

But, that may be a peak / dead center value - it may be a lot lower at the edges. Most lights fall off pretty steeply at the edges [of the grow space], especially at short distances (and 12-inches is pretty close). If you have them in hand, you can try using the Photone smart phone app to measure their PPFD across the grow space.

Adding a gel or filter will subtract colors from the spectrum and lower overall intensity - it wouldn't add any additional intensity for the colors it lets through. You'd be better off leaving those as-is unless you had way too much light to begin with.

You'll be able to grow something with those lights, but I wouldn't recommend it. You'll be spending enough effort over the grow trying to get ventilation, nutrients, etc just right that handicapping yourself with those lights at the start wouldn't be worth the cost of a $150 - $200 budget LED grow light for that space.

 

[Hok]

Check the migro cat on YouTube. He has a lux meter hack for different spectrums. For example 1000 par is 40000 lux on my meter at 3500k. He dose the test side by side with an apogee par meter pretty cool.

 

[Bruce Campbell]

Check the migro cat on YouTube. He has a lux meter hack for different spectrums. For example 1000 par is 40000 lux on my meter at 3500k. He dose the test side by side with an apogee par meter pretty cool.

A) Here's the MIGRO page for lux meters that Hok is referring to, and here's the MIGRO page evaluating phone apps.

Note that converting lux to PPFD depends on the specific spectra of the light source, and conversion factors / apps usually have options for common grow sources such as 3500K / 6000K / "Red + Blue" / etc. The 5000K for your lights isn't a typical spectra used in grow applications, so your conversions will be a bit off.

B) Circling back to your original question, there's nothing too horrible in itself about using a typical white spectra for growing. If you do want to modify it to add additional red / blue / etc, then you can use supplemental lighting like RapidLED enhancement pucks for specific wavelengths.

 

[Tony420]

Hmmmm Thanks, I so much appreciate the links and info/advice. I was hopeful a setup I used for starting vegetable seeds in the past could be repurposed. Maybe it could be a good environment until flowering commences?

Regarding the 26,000 lux was 12 inches above the 18 inch plants with the lights being almost 5 foot off the ground. (It makes you squint for sure)

 

[Tony420]

@Tony420 welcome to AFN.

Blue Colored glass changes the color your eyes see by filtering out the other colors. It does not change the photons wave length. So the simple answer is no that won't help. The plants will just get less white, red or green light.

Thanks. I thought the "filter" would be allowing more of that spectrum to get to the plant.

 

[Tony420]

Prof. Bugbee has some good videos explaining basic considerations for grow lighting - here's his youtube channel, and this video is a pretty good primer. (MIGRO's channel and website is also a very good source for reviews and info.)

26K lux with those lights should be somewhere between 300-400 PPFD - which is decent for germination and seedlings, but you'd normally want ~2x that for veg and ~3x that for flowering. Running 24 hrs a day for autoflowers, you would hit around 30 DLI, which is a decent value.

But, that may be a peak / dead center value - it may be a lot lower at the edges. Most lights fall off pretty steeply at the edges [of the grow space], especially at short distances (and 12-inches is pretty close). If you have them in hand, you can try using the Photone smart phone app to measure their PPFD across the grow space.

Adding a gel or filter will subtract colors from the spectrum and lower overall intensity - it wouldn't add any additional intensity for the colors it lets through. You'd be better off leaving those as-is unless you had way too much light to begin with.

You'll be able to grow something with those lights, but I wouldn't recommend it. You'll be spending enough effort over the grow trying to get ventilation, nutrients, etc just right that handicapping yourself with those lights at the start wouldn't be worth the cost of a $150 - $200 budget LED grow light for that space.

I built the overhead light panel. It is four of the 4 foot LED lights (in the attachment) spaced evenly across the 24 inch width. It covers the 2 x 4 foot area pretty thoroughly. I had 2 x 4 foot LED drop lights laying around and mounted them vertically on both of the 4 foot sides, even with the bulk of the vegetation zone.

 

[Bruce Campbell]

I built the overhead light panel. It is four of the 4 foot LED lights (in the attachment) spaced evenly across the 24 inch width. It covers the 2 x 4 foot area pretty thoroughly. I had 2 x 4 foot LED drop lights laying around and mounted them vertically on both of the 4 foot sides, even with the bulk of the vegetation zone.

If it's built-out already, I'd try a first cannabis grow and see how they do and maybe add some of those enhancement pucks I mentioned for flowering. That way, you'll have a better idea what to look for if you upgrade later.

The next challenge people usually have is temp / humidity control, so the second factor people usually consider in grow lights is heat efficiency (PPF/watt, where PPF is the photosynthetic equivalent of lumen). Cannabis probably grows faster / uses more water than the other vegetables you were growing in that space, so you may have a learning curve / need some tweaks to the ventilation, which a first grow can also help you sort out.

 

[Tony420]

If it's built-out already, I'd try a first cannabis grow and see how they do and maybe add some of those enhancement pucks I mentioned for flowering. That way, you'll have a better idea what to look for if you upgrade later.

The next challenge people usually have is temp / humidity control, so the second factor people usually consider in grow lights is heat efficiency (PPF/watt, where PPF is the photosynthetic equivalent of lumen). Cannabis probably grows faster / uses more water than the other vegetables you were growing in that space, so you may have a learning curve / need some tweaks to the ventilation, which a first grow can also help you sort out.

Thanks. Actually, I did start some "bag seeds"(?) in April. Lets just say that I'm not used to growing much more than spider plants indoors. I thought, give them lots of food to grow big. Some were growing real good. When I got to the 12/12 flowering stage, the remaining plants got mini flowers (maybe two three flowers) everywhere. I'm looking to start over (with the bag seeds) until I can get myself used to indoor growing. I was thinking one of those enhancement pucks would be a good idea. I do want to switch to autos as soon as I'm sure I'm not going to ruin $100 worth of seed.