Ask a Question forum: light spectrum. 5000K for growing?

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Name: alex
southern missouri. (Zone 6b)
Container Gardener Cactus and Succulents Herbs Plant and/or Seed Trader
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alex22ccc
Nov 17, 2014 2:54 PM CST
ok, i finally went to wal-mart and grabbed some new CFL's for my indoor grow box.

before, i was using these two large 42 watt CFL's that were very "warm white" light (2700K) and they were hurting my plants...
Thumb of 2014-11-17/alex22ccc/a70387

so i did a bit of research on light spectrum and plant growth. and found out how having only "warm white" light can do bad things to plants.. stretch them out, etc...

so i went out and got 4 of these, (19watt, 1300 lumen for each) and a color temperature of 5000K.

Thumb of 2014-11-17/alex22ccc/e5b14c

im getting only a little less lumen than i was before, (5200 instead of 5400)
but i think giving my plants a balanced light spectrum is well worth it...

thing is... it seems like they are growing slower.. enough to notice.

so my question is, is 5000K color temperature decent for growing???



Name: Ken Ramsey
Starkville, MS (Zone 8a)
[url=www.tropicalplantsandmore.com]
Orchids Greenhouse Vegetable Grower Ferns Region: United States of America Hummingbirder
Composter Bromeliad Master Gardener: Mississippi Cat Lover Tropicals Plumerias
Image
drdawg
Nov 17, 2014 5:13 PM CST
Hum, the "daylight" is certainly better than the "warm white". Can you put up some inexpensive T-8 shop lights, with 2-4, 4' fluorescent bulbs per fixture? You can up the K to 6500 and your lumens will be doubled per tube. Some people will use those 4 bulb, 4' fixtures and put 2 or 3 6500K and 1 or 2 4500 K fluorescent bulbs in them for a broader spectrum. I like the 6500 K but anything above 5000K will work pretty well. Those CFL bulbs are just really kind of weak in intensity and you'll need an awful lot more of them to cover much of an area over 2'x2'.
drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.
Name: alex
southern missouri. (Zone 6b)
Container Gardener Cactus and Succulents Herbs Plant and/or Seed Trader
Image
alex22ccc
Nov 17, 2014 8:06 PM CST
thanks for the reply ken, your probly right about needing more light. but i have them in my 3'x3'
box. the picture makes it look dark.. but its pretty bright in there.. i dont want to go over 100 watts total, because anything more than that is over 5$ extra on my electric bill per month :P

i could upgrade the 4 lightbulbs to 23watt bulbs that put off 1600 lumen instead of 1300, but thats about it, do you think that would help much?
Name: Rick R.
near Minneapolis, MN zone 4a
I was one of the first 300 contributors to the plant database! Garden Sages The WITWIT Badge Garden Photography Region: Minnesota Plant Identifier
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Leftwood
Nov 17, 2014 8:26 PM CST
Lining the plywood "ceiling" with tinfoil to reflect unused light would help.
Name: alex
southern missouri. (Zone 6b)
Container Gardener Cactus and Succulents Herbs Plant and/or Seed Trader
Image
alex22ccc
Nov 17, 2014 8:28 PM CST
i ran out of foil :P
but i plan on it
Name: Ken Ramsey
Starkville, MS (Zone 8a)
[url=www.tropicalplantsandmore.com]
Orchids Greenhouse Vegetable Grower Ferns Region: United States of America Hummingbirder
Composter Bromeliad Master Gardener: Mississippi Cat Lover Tropicals Plumerias
Image
drdawg
Nov 17, 2014 9:01 PM CST
Alex, you have done about all you can. Something reflective would help so go ahead and do that. When your plants outgrow that 3'x3' box and you need to enlarge it, just remember to plan on using a 4'6" shop light and go with a 4-tube fixture.

Good growing. Thumbs up
drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.
Name: alex
southern missouri. (Zone 6b)
Container Gardener Cactus and Succulents Herbs Plant and/or Seed Trader
Image
alex22ccc
Nov 18, 2014 12:18 AM CST
i actually had a shop light, just a cheap one, 4' x2 (two 4 foot bulbs)
it worked fine, then i hooked it up to a timer, rotated the timer a few times to make sure it turned off & on (not too fast)
and it just stopped working, plugged it in to several wall outlets to make sure it wasn't the timer, and nothing..... do some shop lights have some sort of safety feature i dont know about or something?
Name: Ken Ramsey
Starkville, MS (Zone 8a)
[url=www.tropicalplantsandmore.com]
Orchids Greenhouse Vegetable Grower Ferns Region: United States of America Hummingbirder
Composter Bromeliad Master Gardener: Mississippi Cat Lover Tropicals Plumerias
Image
drdawg
Nov 18, 2014 7:26 AM CST
The inexpensive shop lights have a built-in ballast, and the ballast probably went out. The ballast can easily and cheaply be replaced, but most people (like me) will simply salvage the bulbs and replace the shop light with a new one. Rolling my eyes.

Last spring, I got two new shop lights at Lowe's. I wanted to increase my total lumen output in the "Orchid" greenhouse. None of the two worked. The bulbs would dimly come on but never really light up. The ballasts were defective. Of course both of them were made in China. I took them back and replaced them with practically the same shop lights but from a different company. They worked fine and are still working fine. They were (naturally) also made in China. Thumbs down

I have eight shop lights, all like yours @ 4'x2 bulbs. They are all on timers, so the timer you used had nothing to do with the light failure. I now wished I had put in 4'x4 bulbs. Twice the lumen output but not a lot more expensive to purchase or to run. As these eight slowly fail (and they will), I will replace it/them with that 4'x4 fixture.

drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.
Name: Rick R.
near Minneapolis, MN zone 4a
I was one of the first 300 contributors to the plant database! Garden Sages The WITWIT Badge Garden Photography Region: Minnesota Plant Identifier
Image
Leftwood
Nov 18, 2014 10:32 AM CST
It's a pretty sure bet that any inexpensive shop light fixture will come with an even cheaper ballast. And again, it's another pretty sure bet that any replacement ballast will be of a much higher quality. At Home Depot, at least the ones in Minnesota, they only carry American made replacement ballasts. If you shop for a new ballast, it's important to know what kind you need. Although both T8 (more energy efficient) and T12 lamps (less energy efficient) have the same pin configuration, they are usually not interchangeable with any given ballast. If the replacement ballast you buy comes with more wires than your original ballast, there should be directions included on how to hook it up correctly. But it is easier to just get a ballast with the same number of wires as your original. Its best to bring your original ballast with you to the store, so you know that the new ballast will fit into the old fixture. They are not all the same shape. Get a rapid start ballast, not an instant start ballast, if the unlikely option presents itself.


Electronic vs Magnetic Ballasts

--- Both types are directly interchangeable, as long as they are specifically for the same lamp configuration.
--- Electronic ballasts are more energy efficient.
--- Electronic ballasts are more adaptable to different applications and fixture types (i.e. number of lamps per ballast, and series or parallel hook up).
--- Electronic ballasts may produce radio frequency interference if the ballasts operates within that specific frequency range (rarely problematic).
--- Electronic ballasts do not hum as magnetic ballasts often do.
Name: Ken Ramsey
Starkville, MS (Zone 8a)
[url=www.tropicalplantsandmore.com]
Orchids Greenhouse Vegetable Grower Ferns Region: United States of America Hummingbirder
Composter Bromeliad Master Gardener: Mississippi Cat Lover Tropicals Plumerias
Image
drdawg
Nov 18, 2014 12:41 PM CST
Good information, Rick. Thumbs up
drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.
Name: alex
southern missouri. (Zone 6b)
Container Gardener Cactus and Succulents Herbs Plant and/or Seed Trader
Image
alex22ccc
Nov 18, 2014 3:58 PM CST
sounds good to me ken :P

thanks for the info guys, but for now im just gonna stick with my CFL's..
if i need more lumen output, i can always use 4 of the 42-watt 2700 lumen CFL's.. and actually get the 5000K-6500K this time Sticking tongue out
that should do the trick.. i will just have to accept the extra 10$ on my electric bill i guess

but once again thanks for the info guys.. its good to know it might not of been my fault that my shop light randomly went out Big Grin
Name: Ken Ramsey
Starkville, MS (Zone 8a)
[url=www.tropicalplantsandmore.com]
Orchids Greenhouse Vegetable Grower Ferns Region: United States of America Hummingbirder
Composter Bromeliad Master Gardener: Mississippi Cat Lover Tropicals Plumerias
Image
drdawg
Nov 18, 2014 5:14 PM CST
I tip my hat to you. Thumbs up
drdawg (Ken Ramsey) - Tropical Plants & More
[url=www.tropicalplantsandmore.com]www.tropicalplantsandmore.com[/url]
If God wanted me to touch my toes, he would have put them on my knees.

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