I did a search and couldnt find the answers i am looking for so herer we go.

for years i have used 4 foot shop lights. i would buy those plant bulbs at walmart and they have served my needs. my question is will the regular light tubes work. some in the plant biz once told me that light was light. and the normal tubs are just as bright as the grow light. and reading the info on the tubes i really dont see much of a differance.

anybody have any thoughts or experience.

just a note. right now i am using a 2 footer in my bathroom my wife picked up at a yard sale. its an (under cabnet light) and it seems to be working fine. but i do not know what king of tube is in it.

I'm using the T8 4ft daylight bulbs with $10 shop light fixture from walmart. So far so good.

floressence dont use alot of power thats why i go with them

I use the T5 grow lights. They are low energy grow lights. Haven't noticed a spike in power costs. Dave, I had tried regular grow lights from Walmart on my aquaponics system and the plants did ok but once I added the T5 lights the exploded with new growth. So thats my input on it. Seemed to make a difference.

I use the daylight 4' flourescent and they work fine. It keeps the plant from getting spindly and that is my goal.

I am just looking to sustain rooted cuttings until spring. i plan on building an out building just to hose my plants next year sometime and then will invest in the high end lighting. just got to get by until then. right now i have 42 cuttings goin. two desert king trees in gal pots and three miracle fruit seedlings under a 2 foot under cabnet light doing just fine. i have a 4 foot shelf in my laundry room that the wife has been kind enough to let me use for expanding and i have a four foot shop light but my grow bulbs went out. i do have the (normal) bulbs that came with the light, and am thinking they may do for the short term of a few months until march, april at latest. but i am not 100% i would hate to root 300 cuttings and have them go down to a light issue. 

Read up on photosynthetically active spectrum. 



Or more simply




5000K fluorescents do a great job with this except for the far blue-violet.  They are better than 3500K for the deep reds.  I can't find a comparison of 5000K with 2700K.  6500 K will out do the 5000K  at the 420 nm PAR peak.  I use mostly 5000K tubes with one 6500K and one 2700K CFL supplement on each shelf.  It's important to have some light at 670 nm.  That wavelength stimulates chloroplast multiplication. 

CFL Comparison.  Note there's not a lot of infrared but the curves are extended there to meet their labels.  Either that or the chart is totally bogus  :)




My grow room uses 3 foot square shelves.  1 dual tube 4' T8 shop light on each end (32 watts each bulb, 128 total) plus 2 23 W CFLs in the middle for a total of 174 W per shelf.  That worked very well for me as long as no part of any plant was shaded.  They were all baby cuttings but some grew over a foot in that lighting with no signs of leggyness or stretching.  Each shelf is 9 sq' which can fit 25 1 gal pots with small cuttings.  As the plants get bigger and start to shade each other I have to spread them out more.  Last year I had 7 shelves for a total of 1218 W on for 14 Hrs every day.  17.052 KiloWatt-hrs.  At 10 cents per KW-Hr that's ~ $1.71 per day, $51.16 per month.  Now I wish I hadn't figured it out.   :)     This year I only have 4 shelves so I guess that's an advantage.   That year the goal was to grow everything as fast as possible while only having to water every third day.  If you were willing to water every day, 16 hours of light would be better.  You could probably get away with fewer hours if you wanted to maintain a small size.  This year I've ripened 2 Panache and a Violette de Bordeaux is about to get ripe with this arrangement.  Generally all the lights are closer to the plants but I ran out of chain.  The shop lights are tilted to allow for shorter plants on one side and longer plants on the other.







The fig looks black because it's a purple-blue color right next to the 2700K CFL.

Hey bob is that a sopote growing there? thanx for the info.

You get a wider range of light spectrum if you use both warm and cool tubes. Not real critical for keeping figs alive during winter, but if you want other plants to flower and flourish use warm and cool together. Cheaper than the grow tubes and arguably as effective.

Bob,

That is the information I was looking for when I asked a month or more ago about what lights would be best for a greenhouse. Yea!

I thought I answered it there, too.  Didn't I?

Dave, I'm not sure which plant you mean but this is the only shelf with more other things than figs.  There's citrus, Brugmansias and a few others.  No Sapotes

BTW, Jon, when I get more $$ I'm going to build some LED bars.  Waaay cheaper than fluorescents to run.  Plus there's an LED that peaks at 670 nm once it gets hot.  I'll try to find the post but in the mean time if you or a volunteer is reasonably handy around electronics, home made LED is the way to go.

I'm putting out 14,400 Lumens per shelf but a lot of that goes other places than the plants.  Tomorrow I pick up 100 feet of mylar I ordered to help that somewhat.  An XML LED mounted on an aluminim U channel will easily put out 500 Lm without getting very hot  You can get them up to 1500 Lm each but they get very hot and both their efficiency and lifespan is less.  For flashlights a lot of people feel that 1000 Lm is a good compromise.  A dimmer would be useful to get the optimum balance in your particular set up.  The LedEngin LZ4-40R200 will put out light at 670 nm at operating temperature which encourages the growth of chloroplasts.  Plus the LEDs are much more directional so 14,400 Lm of omnidirectional fluorescents will probably be equaled by less than 10,000 Lm LEDs.

I'm guessing alternating 6500K, 4500K and 2700K XM-Ls  4-6" apart depending on how much current you're going to feed them, 1 bar on either side with 1 bar above, alternating which LED starts off is good.  The LedEngin LEDs will have to be on separate bars, one on each side.  Or wired separately if put on the same bar as the XMLs.  You'd need about 9 - 18 XM-Ls to get 9,000 Lms, 6 on each bar using a 30" bar that's 5" between the LEDs (2.5" at each end) should work well.  For your greenhouse you might want to do 8' bars with similar spacing.  LEDs have to be further away from the plants than fluorescents because their operating temp is about 200 degrees F.  Now that high temp exists only in the space of about 1/25 sq" but you still can't put a 10W LED 4" away as you can with a fluorescent. 

LEDs have to be wired in series with a constant current driver (power supply).  Only identical LED types can be on the same circuit.