pastrycheffowler
Full Member
Posts: 53
Joined: Sun Mar 24, 2013 12:53 am
Location: orange county CA

What exactly are the grow bulbs

i just got a new germination dome with a heatmat today, and the instructions state to use a grow bulb with it, i am looking at starting my seedlings inside and taking them outside once they are ready. i have reptiles so i have several uvb reptile bulbs laying around that simulate tropical and desert sun, my question is can these work? do i need a bulb to start seedling germination?

evtubbergh
Green Thumb
Posts: 532
Joined: Sun Jan 13, 2013 11:52 am
Location: South Africa

Re: What exactly are the grow bulbs

Hiya

You don't need the bulbs for seed germination unless the seeds specifically need light to germinate. Mostly though, you don't.

Once the plants come up though light will make a big difference. The UV lights for reptiles are the same thing but it can be quite interesting to see what wave lengths are produced by different lights hence the two kinds that you have.

Depending on the plants and the stage of growth they are at you might want to use different bulbs. That said don't worry if you don't want to buy new bulbs just try with what you have.

User avatar
hendi_alex
Super Green Thumb
Posts: 3567
Joined: Sun Jul 06, 2008 11:58 am
Location: Central Sand Hills South Carolina

Re: What exactly are the grow bulbs

Most any spectrum fluorescent bulb can be used to start seedlings. I tend to mix 2700 degree and 6500 degree bulbs but have grown solely on one or the other and have always gotten good results with seedlings. The color of light is mostly important when trying to get plants to flower in artificial light.
Eclectic gardening style, drawing from 45 years of interest and experience. Mostly plant in raised beds and containers primarily using intensive gardening techniques.
Alex

pastrycheffowler
Full Member
Posts: 53
Joined: Sun Mar 24, 2013 12:53 am
Location: orange county CA

Re: What exactly are the grow bulbs

cool thanks guys, i will let you all know what the outcome is

tenderloingardener
Cool Member
Posts: 71
Joined: Fri Jul 05, 2013 11:39 pm
Location: San Francisco

Re: What exactly are the grow bulbs

By special Order of the Progressive Mafia of San Francisco, all bulbs sold in this city have to be fluorescent. Unless they are for a special use. Like a crystal chandelier or the Lt. Governors tanning bed. :roll:

Anyway, I was going to buy some/one of those clamp on shop lights, but as a real conservationist who also happens to be somewhat broke, I decided to take a stroll through a local institution called Thrift Town. Why buy something new when you can reuse?

Well, it's slim pickings these days-seems like everybody is somewhat broke- but I found several spot lights. As in stage lights. One of them had a high wattage filament bulb (sshhh. I don't want to get busted 8) ) in it. I got that one. I'm thinking-great! It's full spec, it's warm, but if you take the spot focus off, it's not gonna fry anything, and I'm not growing a crop anyway-just a few herbs I got a late start on, plus some of "my" sunlight is gets blocked by the giant Art Deco fancy-pants condo unit across the street. I need more LIGHT. In fact, the bulb in there looks just like the grow lights my mother used to use on her "wall of plants" (actually brass and glass shelving unit-oh the '80's. So mauve and breakable! :> ) to keep her 30 or so houseplants alive during the dark winters in AK.

But I keep reading fluorescent, fluorescent, and fluorescent. Why? If I need to switch over, fine, but I'd truly appreciate an explanation. Be as technical and nerdy as you want. I love it. :wink:

Thanks in advance for reading this, and any kind of information you can give me.

In the heart of the city,
Shawna
Shawna

tenderloingardener
Cool Member
Posts: 71
Joined: Fri Jul 05, 2013 11:39 pm
Location: San Francisco

Re: Why fluorescent?

Hello people of the light. I went on my own, and tried to couple this with barely remembered work with mass spectroscopy, and what I came up with is that fluorescent bulbs emit mostly the blue and red wavelengths, less of the yellow and green. Plants (mostly) are green because that wl is being reflected, while others in the visible spectrum are being absorbed or blocked.

How am I doing? Because then I find myself back at page 1. Full spectrum fluorescent lights. Now, if one has a lot of stuff this would be a big energy saver, pocket and planet, but just talking about extra hours of light needed due to cityscape blockage-is there any reason for me to use fluorescents instead of the old timy light like my mother used? I've kept some plants outdoors with only the sun I get as an experiment (not ideal-they should be clones with exact same pots and mix) but clearly the light I'm using makes a huge difference.

Thanks, I'm just trying to get some information from my betters. If the fluorescents are really worth it in my situation, I'll get one.

Shawna
From the Heart of the City
Shawna

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Re: What exactly are the grow bulbs

You can't use incandescent filament lights with plants, because they give off way too much heat. By the time you get the light close enough to your plant to do any good (remember light diffuses by the square of the distance), you are cooking the plant.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

Return to “HYDROPONICS FORUM”