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What bulbs do you use in your fluorurescent setups?

R

roadhouse

Currently I have two shop lights over 4 flats of plants each with 2 T12 GE office lights (6500 K). I used to have one each of 6500K and 3500K in each shop light but realized that the plants below the 3500K seemed to be leaning towards the 6500K so I switched to all 6500K. I am wondering if there are better lights out there for my application. Looking at the spectrum I see this produces lots of light in the blue but not all that much red. I am thinking that at the earlier stage blue is most important, is this true? Anyone have any good links relating to this?
 
I have the same set-up as you do. 2 Shop lights with T-12 GE bulbs 6500k and 3000k and 1 shoplight with both bulbs being the GE Plant and aquarium bulbs. Today I just added a track light system with 6 CFLs: 4 6500k and 2 2700K. From what I have read on here, many people have similar set-ups until you get into the LED, HPS or MH set-ups.
 
Most of my plants were under 105 watt, 5K CFL bulbs. They have a spike in the violet range and also in the red/orange range.

Mike
 
See link below. This guy has some controlled experiments that show a GE Plant and Aquarium bulb seemed to produce noticeable
results over other bulbs. They are available at Lowes (at least they are at mine in Ohio) but they are $9.99 per bulb
vs. $3.99 for a two-pack of 4100k bulbs. Due to cost, I ended up putting one GE bulb and one cheap 4100k bulb in each of my
8 shop lights and got good results. Would they have been better with just the GE bulbs? Not sure. Maybe next year I'll
run some experiments of my own.

http://www.waynesthisandthat.com/fluorescent.html
 
On the 6500k bulbs, what is the product number on the bulb (ie. F40T12/DX....etc.)? On most bulbs that you can buy from the hardware store most of them do not tell you what the CRI (color rendering index) happens to be on each bulb. I would suggest either going with grow bulbs or getting a fluorescent that has a very high CRI (anything 80+) as well as a high kelvin temp. (6500k+).
 
I've had great success using the cheapest walmart bulbs available but usually I like to mix the bulbs for a more complete spectrum
 
secretz said:
On the 6500k bulbs, what is the product number on the bulb (ie. F40T12/DX....etc.)? On most bulbs that you can buy from the hardware store most of them do not tell you what the CRI (color rendering index) happens to be on each bulb. I would suggest either going with grow bulbs or getting a fluorescent that has a very high CRI (anything 80+) as well as a high kelvin temp. (6500k+).
Click to expand...

They are F40T12. GE daylight 40. Light output 3050 lumens, color temp 6,500K. I currently have 4 of them over about 96 plants in 4 flats. 24 per flat. Each cell is 2.5 in. wide x 3 in. long x 2.5 in. deep.
 
I have a setup that uses 4 6500k shop lights and the sprouts seem to love them. I only use the light setup for new plants and even then only for about 6 weeks until the plant is big and strong enough to go under the 400 watt MH. After about 6 weeks under the 400 MH they slowly get transitioned outside where only a few select plants are kept inside which then go into a 400 watt HPS and then again to a 1000 watt HPS when ready.
 
LGHT said:
I have a setup that uses 4 6500k shop lights and the sprouts seem to love them. I only use the light setup for new plants and even then only for about 6 weeks until the plant is big and strong enough to go under the 400 watt MH. After about 6 weeks under the 400 MH they slowly get transitioned outside where only a few select plants are kept inside which then go into a 400 watt HPS and then again to a 1000 watt HPS when ready.
Click to expand...

Guy,

If you need to keep seedlings under that much light for 12 weeks, you need a different system! In six or no more than eight weeks, your plants ought to be ready to face the dirt!

Mike
 
My plants usually get 3+ months under floro lights and they seem to grow quite well, and quite compact for me. I think its important to have a good reflector on your lights and mylar or flat white surface to reflect back as much light as possible and limit wasted light
 
chillilover said:
I was told 2700k don't have enough blue for good growth...........
Click to expand...

Yes, I read somewhere that 2700k is good for blooming and that kinda thing. I think the result so far has been pretty good, not optimal but good enough. I've posted a few pictures on this forum so go take a look. Next year I'm going to get some 6500K lights.
 
chillilover said:
I was told 2700k don't have enough blue for good growth...........
Click to expand...

2700k is the pinkest you can get on the color spectrum...the higher you get in the kelvin temperature the bluer the color. I've been told that
for the best results you should use the higher kelvins for stem and leaf growth...and lower kelvins for bud growth...or aleast that's what've been told.
 
I use GE Daylight 32 4ft watt T-8 6500k color temp, 2700 lumens , my setup has 4 of these bulbs per shelf.
I think I pay like $8.99 for 2 bulbs and they work awesome for seedlings until Im ready to pot up and move them outside.
and yes the blue part of the spectrum is better for early foliage growth and the red spectrum for blooming and fruiting. but if you plan on keeping them under the light for fruiting I would invest in a switchable MH / HPS setup and not use fluorescents for long term lighting.



-Rich
 
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