What's new
  • Please note members who been with us for more than 10 years have been upgraded to "Veteran" status and will receive exclusive benefits. If you wish to find out more about this or support IcMag and get same benefits, check this thread here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

Controlled Spectrum experiments

ganjourno

Member
There are many threads around the net on MH vs HPS vs LED and various flavors thereof, but such tests may have wildly different efficiency and thus they are controlling for watts rather than spectrum.

I'm looking for a test that is specifically controlled for spectrum. For example, three grows from clone to bag with identical PPFD at the canopy across four spectrums:
2:1 Blue:Red
1:1 Blue:Red
1:2 Blue:Red
1:3 Blue:Red

This is possible with today's LED technology.

The point is to find the best spectral ratio for flowering so that the most efficient emitters of that profile can be identified.

Is anyone aware of any well controlled experiments on spectrum?
 

Andyo

Active member
Veteran
Last edited:

Phaeton

Speed of Dark
Veteran
I did similar side by sides using equal photon counts with the different spectrums. Pretty much same same as you with slightly different wording.

That was in 2012, times have changed the technology quite a bit since then. My final results indicated a hybrid lighting system to balance the spectrum fairly close to that of the sun, those fringe wavelengths at the edge of the spectrum have an outsize effect compared to the percentage of total light they contain.
 

Phaeton

Speed of Dark
Veteran
flowering veg was with osram POWERSTAR HQI 1000,s pre uv filter era
QUOTE]

I am impressed, I did not realize there were still working bulbs from the late 1950's when it was possible (although difficult) to find an illegal bulb passing UVB. Illegal to even manufacture in the 1960's.
Today you would have to remove the outer envelope to get to the UV, regular glass and plastic stops UV, it takes a specially formulated glass to let UVB pass. This is highly not recommended as the emitted UVB from an HID is 100 to 1000 times the percentage in sunlight.

The rules have been relaxed and I have found two bulbs advertising UVB that actually move the UVB meter needle off zero.
Solis Tech managed 2 uw and Sun Pulse flickered between 0 and 1 uw. Rules are difficult to bypass. The minimum required for plant response is 50 uw at the leaf.
Lumitex or T5 for UV at effective levels.

Part of the continued research done while gardening.

PS: UVA and Blue elicit the same response from plants, it is the UVB that has the destructive power needed. This my be the basis for much confusion about UV and plants. UVA is a human designation for the cutoff point where our eyes no longer receive the light. The plants are unaware of this and treat UVA and Blue as one and the same.
 
G

Guest

I have a couple Reptisun 10.0 T5 22" in fixtures like the guy in the YouTube. I used them in flower over two plants in my small tent. I am not sure if the helped or not but I plan on hanging them back up within a few inches of top of plants again when I flip my current grow in about 4 weeks.
Some where around here was a guy claiming some particular T5 tubes were giving substantial readings at 3 FEET. I'm subbed.

Here is the brand mentioned.
https://www.ushio.com/product/ultra5-t5-linear-fluorescent/

I can't find the product talked about but that is the brand. I have the actual tubes link bookmarked at home.

I find the 3 FEET distance claim something that needs some proof but it's interesting. No hijack ment.
 
Last edited:

Andyo

Active member
Veteran
3rd world

3rd world

flowering veg was with osram POWERSTAR HQI 1000,s pre uv filter era
QUOTE]

I am impressed, I did not realize there were still working bulbs from the late 1950's when it was possible (although difficult) to find an illegal bulb passing UVB. Illegal to even manufacture in the 1960's.
Today you would have to remove the outer envelope to get to the UV, regular glass and plastic stops UV, it takes a specially formulated glass to let UVB pass. This is highly not recommended as the emitted UVB from an HID is 100 to 1000 times the percentage in sunlight.

The rules have been relaxed and I have found two bulbs advertising UVB that actually move the UVB meter needle off zero.
Solis Tech managed 2 uw and Sun Pulse flickered between 0 and 1 uw. Rules are difficult to bypass. The minimum required for plant response is 50 uw at the leaf.
Lumitex or T5 for UV at effective levels.

Part of the continued research done while gardening.

PS: UVA and Blue elicit the same response from plants, it is the UVB that has the destructive power needed. This my be the basis for much confusion about UV and plants. UVA is a human designation for the cutoff point where our eyes no longer receive the light. The plants are unaware of this and treat UVA and Blue as one and the same.

I looked today the lamps i used here 5 yrs ago no longer availble.
lolI was born in the 50,s

but i think these may be worth testing as supplemental
http://www.ebay.com/itm/Aquarium-15...hash=item33b9e41908:m:mEp6f_tZGd6L94NzOkkwb7g
 

Latest posts

Latest posts

Top