New to growing your own tomatoes? This is the forum to learn the successful techniques used by seasoned tomato growers. Questions are welcome, too.
|
|
Thread Tools | Display Modes |
|
February 11, 2021 | #1 |
Tomatovillian™
Join Date: Dec 2017
Location: Ústí nad Labem in the north of the Czech Republic
Posts: 332
|
Hello,
you really have a green thumb. That's impressive. I had to look up Bok Choy and that's one thing that I'll never grow. And the same applies to Nappa Cabbage as it was just food for earwigs and they didn't leave anything for me last year. Actually, there aren't any UV LEDs. Not even NUV - Near Ultra Violet (400 nm). I was asking because I believe for growing seedlings UV is helpful as the plants don't get badly sunscalded when they finally go out. That's why I still use fluors despite their much lower efficiency. It's visible that Viparspectra works well though. Do you shade the seedlings when you transplant them in your garden? And aphids? Even my home is infested with them. Strangely enough, they don't like my tomatoes. Milan HP Last edited by Milan HP; February 11, 2021 at 07:51 AM. |
February 11, 2021 | #2 |
Tomatovillian™
Join Date: Jan 2018
Location: Philly 7A
Posts: 739
|
I harden off for a week or two by placing under the deck. I get an evening sun and this "lazy" way has worked out for me the last 4 years or so.
I'm not really sold on the UV yet, but I am still researching it. I started looking into the UV lights, (UVA AND UVB) I already have the UVA and UVB bulbs for the the turtle tank, but want to see if I can incorporate them into the grow table as led's. What do you think about these? 395nm - 410nm https://www.homedepot.com/p/UV-LED-2...L240/309569447 |
February 11, 2021 | #3 |
Tomatovillian™
Join Date: Dec 2017
Location: Ústí nad Labem in the north of the Czech Republic
Posts: 332
|
What do you think about these? 395nm - 410nm
https://www.homedepot.com/p/UV-LED-2...L240/309569447 I've been denied access. I don't really understand why.I think the best UV LED should have at least UVa and a little UVb. Milan HP |
February 11, 2021 | #4 | |
Tomatovillian™
Join Date: Jun 2016
Location: Illinois
Posts: 162
|
Quote:
https://www.amazon.com/AgroMax-Foot-...EVC05E2702FH9F And everyone says the UV's will burn up your plants, so you have to put them on a timer and only give them about 15 minutes, twice a day. Read the Amazon reviewers comments on that. Also it has to have a good metallic reflector, so I ordered this fixture for it: https://www.amazon.com/GrowBright-Hi...2E79BHFYJD6PE1 Also note that LED's are directional, they send out a narrow focused radiation. So if you have one LED strip, your light coverage will not spread out sideways, it will shine straight down in a narrow band. In order to get good canopy coverage, you must have several of them side by side. I've been following Dr Bruce Bugbee who is a scientist that has done research on lighting for NASA. He has many youtube videos you can watch. Here's a general discussion of his, with the guy that did the comparison of the UV Tubes. https://www.youtube.com/watch?v=X1O3OD-dI20 |
|
February 12, 2021 | #5 | |
Tomatovillian™
Join Date: Jan 2018
Location: Philly 7A
Posts: 739
|
Quote:
Yes I agree, that's one of the main reasons I added a 3rd light and turned mine 90°. Its a lot of light but now I just reduce the intensity but get better coverage. What's nice about these "Par" series Viparspectra's is they have a "Secondary Optical Lens" |
|
February 13, 2021 | #6 | |
Tomatovillian™
Join Date: Jun 2016
Location: Illinois
Posts: 162
|
Quote:
I do have to say those are some real beast LED fixtures. They pretty much cover the entire spectrum don't they? But that said, I can't help but wonder if they are really much different than daylight fluorescents, colorwise. They draw a whole lot more wattage than fluors, so are they just much higher in intensity? I haven't compared the PAR ratings, because I don't know what that value is for fluorescents. |
|
February 13, 2021 | #7 | |
Tomatovillian™
Join Date: Dec 2017
Location: Ústí nad Labem in the north of the Czech Republic
Posts: 332
|
Quote:
Light spectrum also speaks for CXBs - it's pretty close to daylight and fairly even in energy distributed at various wavelengths. Milan HP Last edited by Milan HP; February 13, 2021 at 03:26 PM. |
|
February 11, 2021 | #8 |
Tomatovillian™
Join Date: Jan 2014
Location: washington
Posts: 498
|
Could you use something like these? I have the individual ones on my light set-up.
|
February 11, 2021 | #9 |
Tomatovillian™
Join Date: May 2013
Location: RI
Posts: 183
|
The key if you are using LED tubes or bulbs that are replacements for old Flourescent tubes is that you need to get ones in the right color spectra. Either 5000k or 6500k bulbs, or a mix of both.
I've been using these maxlite 5000k shop lights for several years with great results. For a budget friendly option, you can't beat the price. There are also deals for these lights often at local hardware stores, often as low as $10-$15 per unit. You can pack three of these above a 2' x 4' shelving unit, and get over 12900 lumens for 8 ft2, or 1600 lumens per ft2. At 32watts each, that is 96 watts for 3 per 2x4 shelf. Or 102.38 lumens per watt. https://www.amazon.com/MaxLite-Linka...s%2C211&sr=8-5 Last edited by NathanP; February 11, 2021 at 06:50 PM. |
February 12, 2021 | #10 |
Tomatovillian™
Join Date: Jan 2014
Location: washington
Posts: 498
|
With my CXB 3590s I don't have any sunscald problems at all, it sure is nice not to have to harden things off before setting out.
|
February 12, 2021 | #11 | |
Tomatovillian™
Join Date: Dec 2017
Location: Ústí nad Labem in the north of the Czech Republic
Posts: 332
|
Quote:
I've checked on their light spectrum starting at 380 nm. Which means they have some UVa, but the energy radiated at the shortest wavelengths is not really much. What level of light intensity can you reach at the plant tops? Maybe I am totally wrong in believing that it's mainly UV that causes sunscald. My plants indoors get direct sunshine through the windows and the only problem is that glass does not let much UV in. That is on sunny days, which aren't numerous here. And they get scalded as a rule. Do you think CXB 3590s could solve my problem? That would be great, even though they are energy "guzzlers". Milan HP |
|
February 12, 2021 | #12 |
Tomatovillian™
Join Date: Jan 2014
Location: washington
Posts: 498
|
I am measuring 26000 lumens at 16" from plant tops, and 164 lumens per watt isn't what I would call an energy guzzler, not sure where I could fi d a more efficient COB. Maybe you can point me to something more efficient.
|
February 13, 2021 | #13 | |
Tomatovillian™
Join Date: Dec 2017
Location: Ústí nad Labem in the north of the Czech Republic
Posts: 332
|
Quote:
Milan HP |
|
February 13, 2021 | #14 |
Tomatovillian™
Join Date: Jan 2014
Location: washington
Posts: 498
|
No problem at all! I think that I'm running them at 50 watt's on their highest setting, it has a potentiometer as a dimmer so you can just dial them down a bit if they are too bright. The driver for them only costs around 60 or70 dollars.
|
February 16, 2021 | #15 |
Tomatovillian™
Join Date: Jan 2014
Location: washington
Posts: 498
|
The thing that I really like about the CXBs are that they are whit and not a blurpul color, much easier to see the health of the plants.
|
|
|