vintagedvd
Active Member
I wanted better options, but good T5 UV bulbs made outside Europe are almost impossible to buy or are ridiculous expensive. Good fixtures are more available, but not by much. If someone would of told me 3 months ago that I will buy new lights, and T5's on top of that, I would of said he's crazy. I'm not sorry about my purchase, I just hope I didn't throw $100 out the window.
So, from the financial and psychiatric point of view, I could only buy the GT Lightwave T5 2X24W, so I bought it. It comes with 2 stock bulbs that put out almost no UV, so I also bought 2 bulbs of JBL Reptil Sun ; 7500k ; lm 650 ; CRI 90 ; 24W ; UV-A 63% ; UV-B (12%)
I made pictures with the same camera, in the same light conditions, and I've used prescription glasses to measure different levels of UV intensity.
First picture is the control one, lenses without exposure to UV light.
Next picture was made keeping the glasses 10cm(4") below the main light, 4X 50W COB 3070 30G.
I knew it does not produce noticeable UV light, but I was disappointed to see it was true.
Next I tried a regular T8 that I had in the house, with glasses kept at 5cm(2") for 10 minutes.
That's what I call barely any UV. A compact CFL bulb at the same distance had the same outcome. I wonder where's the UV in all the indoor growing because I can't find a light that outputs a decent amount of UV. Maybe someone can test a HID, as I don't have one anymore.
Next I wanted to test the Lightwave T5 fixture, so I placed it up side down on a table, and the glasses hanged above it, shined by the fixture. I wanted to hang them at 50cm(20"), but as I hanged them, the lower lens (singular) was at 45cm(18"), and the upper lens was at 55cm(22"). This data is important in the next test.
As you can see, although this test is made a lot farther than the regular T8, a soft tint is visible. The left lens is thicker (long story) so it's not as tinted as the right one, plus it was "shadowed" (I think) by the lens situated lower, between the light and the left lens. What I'm trying to say is that if you take just one of the lenses as reference(preferable the one on the right), you can make use of this experiment. Hope it makes sense. If not, it will in a second.
I changed the stock bulbs with the JBL ones.
Finally, the effects of the UV light were clearly visible, and the difference in the height and chemical composition of the lenses was noticeable in this test. So noticeable that I decided to repeat the test with both lenses at the same height.
Here the difference of the lenses is more visible. I wanted to see the effects on both lenses so I repeated the experiment with both lenses at the same height of 55cm(22"). Unfortunately I was anxious and didn't put the lenses facing down. There is a slight angle, maybe 10°, but they're definitely not facing perfectly towards the light. Still, the lens showed a good amount of UV at twice the distance from the plants that I plan to keep the light.
For a good comparison I took a picture of the glasses under the plain sun (wearing them) for 10 minutes.
This picture was made on the 29.03.2017 at the 46paralel, north hemisphere, between 10:30-10:40 AM
Conclusions:
Considering this test gave results in images instead of numbers, I still consider it a successful experiment. My plan is to have a moderate UV light, that I can keep on the same timer, at the same schedule and at the same height as the main light. These lights seem to fit the bill as I will keep them at around 30cm. I will lower/raise them if I see it needs adjustments and I will post any changes or info that might seem important to this thread. Because of the heat I grow only 2 times a year and never in the summer, even with LEDs, so it might take a wile until I post some actual results, but I promise that I will.
So, from the financial and psychiatric point of view, I could only buy the GT Lightwave T5 2X24W, so I bought it. It comes with 2 stock bulbs that put out almost no UV, so I also bought 2 bulbs of JBL Reptil Sun ; 7500k ; lm 650 ; CRI 90 ; 24W ; UV-A 63% ; UV-B (12%)
I made pictures with the same camera, in the same light conditions, and I've used prescription glasses to measure different levels of UV intensity.
First picture is the control one, lenses without exposure to UV light.
Next picture was made keeping the glasses 10cm(4") below the main light, 4X 50W COB 3070 30G.
I knew it does not produce noticeable UV light, but I was disappointed to see it was true.
Next I tried a regular T8 that I had in the house, with glasses kept at 5cm(2") for 10 minutes.
That's what I call barely any UV. A compact CFL bulb at the same distance had the same outcome. I wonder where's the UV in all the indoor growing because I can't find a light that outputs a decent amount of UV. Maybe someone can test a HID, as I don't have one anymore.
Next I wanted to test the Lightwave T5 fixture, so I placed it up side down on a table, and the glasses hanged above it, shined by the fixture. I wanted to hang them at 50cm(20"), but as I hanged them, the lower lens (singular) was at 45cm(18"), and the upper lens was at 55cm(22"). This data is important in the next test.
As you can see, although this test is made a lot farther than the regular T8, a soft tint is visible. The left lens is thicker (long story) so it's not as tinted as the right one, plus it was "shadowed" (I think) by the lens situated lower, between the light and the left lens. What I'm trying to say is that if you take just one of the lenses as reference(preferable the one on the right), you can make use of this experiment. Hope it makes sense. If not, it will in a second.
I changed the stock bulbs with the JBL ones.
Finally, the effects of the UV light were clearly visible, and the difference in the height and chemical composition of the lenses was noticeable in this test. So noticeable that I decided to repeat the test with both lenses at the same height.
Here the difference of the lenses is more visible. I wanted to see the effects on both lenses so I repeated the experiment with both lenses at the same height of 55cm(22"). Unfortunately I was anxious and didn't put the lenses facing down. There is a slight angle, maybe 10°, but they're definitely not facing perfectly towards the light. Still, the lens showed a good amount of UV at twice the distance from the plants that I plan to keep the light.
For a good comparison I took a picture of the glasses under the plain sun (wearing them) for 10 minutes.
This picture was made on the 29.03.2017 at the 46paralel, north hemisphere, between 10:30-10:40 AM
Conclusions:
Considering this test gave results in images instead of numbers, I still consider it a successful experiment. My plan is to have a moderate UV light, that I can keep on the same timer, at the same schedule and at the same height as the main light. These lights seem to fit the bill as I will keep them at around 30cm. I will lower/raise them if I see it needs adjustments and I will post any changes or info that might seem important to this thread. Because of the heat I grow only 2 times a year and never in the summer, even with LEDs, so it might take a wile until I post some actual results, but I promise that I will.
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