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cheap Indoor lighting options

Posted: Fri Dec 11, 2009 6:50 am
by Robbie78
Hi for my birthday I received 2 indoor bamboo plants,Bambusa ventricosa 'Kimmei',Chimonobambusa quadrangularis 'Suow', I dont get much sun in my windows and Im considering using some 8000k cfl tube work lights that are about 3 feet long, would this work? or would it be a waste of time, my other option im considering is getting some led grow light bulbs, one for each plant, what do you guys think?

Re: cheap Indoor lighting options

Posted: Fri Dec 11, 2009 2:44 pm
by foxd
Personally I like the four foot long shop lights with GroLux bulbs. The lights put more energy into the red and blue parts of the spectrum.

Re: cheap Indoor lighting options

Posted: Fri Dec 11, 2009 3:33 pm
by Alan_L
Are you planning on keeping these plants indoors always? If so, you probably want to find them a spot with the best natural lighting, and only move them under artificial lighting when they appear to need it (or never, ideally). Keeping growlights above plants in your living room isn't the most attractive solution. =)

Re: cheap Indoor lighting options

Posted: Fri Dec 11, 2009 6:34 pm
by foxd
Alan_L wrote:Are you planning on keeping these plants indoors always? If so, you probably want to find them a spot with the best natural lighting, and only move them under artificial lighting when they appear to need it (or never, ideally). Keeping growlights above plants in your living room isn't the most attractive solution. =)
Some of the plants have been under growlights for years in the basement (No windows!) and look just fine. I also have a greenhouse with growlights in the living room. (No good windows for plants in the house.)

During the Summer most of the plants get moved outside. Among the plants that stayed indoors were one of the Surinam Cherries, Aloe vera, a variegated Ficus, the Raddia brasiliensis, the Gotu kola, Purple Wandering Jew and a Pineapple Plant. Thinking about it, technically one of the Melocanna baccifera also stayed indoors under lights, but I didn't know it was alive.

Re: cheap Indoor lighting options

Posted: Fri Dec 11, 2009 9:17 pm
by Alan_L
I also have plants that mostly stay under growlights in the basement all year. It's not that I was saying it's not possible, but for some reason I thought the original poster wanted the bamboo as houseplants -- you know, integrated into the decor of the living area. In that case, hanging some florescent tubes in the living room isn't the most attractive solution. :D

Re: cheap Indoor lighting options

Posted: Sat Dec 12, 2009 2:57 am
by Robbie78
I plan to keep them inside, its real windy where I live, but i imagine its good to put them outside and give them some fresh air. Also i have a room upstairs in my house where i have one of them so if i needed to put a light up I would do it up there and there is a big window it just doesnt get a ton of sun light. Thanks for your responses

Re: cheap Indoor lighting options

Posted: Tue Feb 23, 2010 2:46 am
by Mark_NoVA
Fluorescent lights are typically used when they can be placed several inches or half a foot or so away from plants--the light isn't all that strong, and they don't give off a lot of heat, so they can be placed closely. (Light weakens with distance.) So they're often used for seedlings.
For a taller plant like bamboo, you probably want to look at a stronger light, such as an HID light.

Re: cheap Indoor lighting options

Posted: Tue Feb 23, 2010 11:54 am
by dudley
you can also place lights vertically so they illuminate along the length of the culms and promote more branching rather than just from the top.

Re: cheap Indoor lighting options

Posted: Tue Feb 23, 2010 2:20 pm
by foxd
One of my "Rules of Thumb" concerning light sources is that the larger the area of the light source the less you have to worry about the distance between it and the plants.

In practice this means if you have a reflecting fixture with multiple parallel fluorescent tubes then you can have it several feet from the plants. This also gives much better penetration of the foliage than a point source.

As far as reflecting surfaces for the light, yes you can get silvered mylar to use, but white material also works.

Re: cheap Indoor lighting options

Posted: Tue Feb 23, 2010 10:14 pm
by Lazlo Woodbine
Flouros ..even with good reflectors are only effective for up to 8-10 ins .

Yes, you can have them almost touching the foliage - but it won't be very effective with any reasonably sized plants.

HID - High intensity discharge are a better option - preferably Metal Halide rather than HPS - High pressure sodium.

MH bulbs have a higher output from the blue end of the spectrum and are more suited for vegatative growth.

You can hang them horizontaly with reflectors - or vertically as bare bulbs - often a better bet if your looking after more than a couple of plants.

HPS are better for flowering .... don't ask me why I know that ... :roll:

edited to add;

Actually after re-reading the thread properly :oops: ... HID wouldn't really be practical for you - unless your plants were in a basement rather than the living room! .... and the're not at all cheap to run if you're going to use them long term.



Laz

Re: cheap Indoor lighting options

Posted: Tue Feb 23, 2010 10:40 pm
by Alan_L
I certainly wouldn't consider HID as "cheap", as the topic started. If you want strong light output, there's really no "cheap" solution available.

Re: cheap Indoor lighting options

Posted: Tue Feb 23, 2010 10:46 pm
by Mark_NoVA
Yep, Laz is right, because light weakens with the square of the distance. So for example, comparing lights 1/2 foot away and 2 feet away, the light 2 feet away isn't 4 times weaker, but 16 times weaker. Thus, you need a stronger light source, not more lamps.

Re: cheap Indoor lighting options

Posted: Wed Feb 24, 2010 2:02 am
by stevelau1911
I would suggest a 300watt or stronger metal halide or hps light because I've seen how strong plants grow under them, but a set up with a 70=350watt cfl where all the plants are between 5-12 inches away seems to work fine for me.

As you can see, they're not really stretching out with this set up.
Image

Re: cheap Indoor lighting options

Posted: Wed Feb 24, 2010 7:45 am
by ghmerrill
if you are considering going with Halides, check out HQI bulbs- a bit more energy efficent, and they work great. you can pick up some nice deals on craigslist from people dumping thier saltwater reef tanks, and the old bulbs from saltwater work great, since the color spectrum downgrades with time to more red.

Re: cheap Indoor lighting options

Posted: Wed Feb 24, 2010 4:15 pm
by foxd
Mark_NoVA wrote:Yep, Laz is right, because light weakens with the square of the distance. So for example, comparing lights 1/2 foot away and 2 feet away, the light 2 feet away isn't 4 times weaker, but 16 times weaker. Thus, you need a stronger light source, not more lamps.
The inverse square law applies to point-like light sources. If your light source has a large surface area, then the light level falls off much more slowly with distance.

Radiation from a point falls off at the inverse the square of the distance.
Radiation from an infinitely long line falls off at the inverse the distance.
Radiation from an infinitely large area doesn't fall off with distance.

Of course in practice the light sources are not infinitely large, but a good enough approximation can be made for growing plants.

As I write this I am sitting in a cubicle in a large room with fluorescent lights placed periodically on the ceiling covering a plane. I notice it is not darker near the floor.