Lighting T5/CFL only thread (the manual)

[DubV]

Question: all things being equal how many plants would you expect to be able to grow under a 4' x 8 bulb HO T5 setup?

Hey bro since you are dwc I wouldn't do anymore than two plants under that fixture. That way you give space for the typical dwc beast structure to develop.

 

[The Horror]

Here's some info I found useful. The listings are by bulb length in feet followed by number of bulbs. For example "2x2" means 2ft long bulbs, quantity of 2. The lumens listed are for High Output (HO) T5 bulbs.

2x2: 4000 lumens
2x4: 8000 lumens
2x6: 12,000 lumens
2x8: 16,000 lumens (fits a 2' x 2' grow space)

4x2: 10,000 lumens
4x4: 20,000 lumens
4x6: 30,000 lumens
4x8: 40,000 lumens (fits a 4' x 4' grow space)

For comparison to both Metal Halide (MH, commonly used for vegging) and High Pressure Sodium (HPS, commonly used for flowering):

250w MH: 18,000 lumens
400w MH: 32,000 lumens
600w MH: 60,000 lumens
1000w MH: 80,000 lumens

250w HPS: 30,000 lumens
400w HPS: 50,000 lumens
600w HPS: 88,000 lumens
1000w HPS: 140,000 lumens

A "lumen" is a unit of measurement which measures the total amount of visible light emitted.

Therefore, lumens alone do not tell the whole story for all forms of lighting. In LED for example we might be more concerned with Photosynthetic Active Radiation (PAR) which is a measure of the spectrums plants use for photosynthesis.

Also note there may be variance in bulb manufacturers, but this is a good general outline.

 

[p man]

great chart...reps for that!...I read you only need 5,000 lums for a plant is that right I know the more the merrier but what about 5,000

 

[p man]

here's a little better picture I'm using 6 cfls...I'm trying to sneak a little of her under my 400 but there's no room...

View attachment 150718

 

[p man]

question i'm running 400 watts of cfl to finish these plants
1 is a 200w 6500k and
the other is a 200w 2700k
my light timers are still set for 20on /4off
will this light schedule be best for flowering under cfl?

nice job reps goin your way!

 

[p man]

now that everyones talked about cfls/t5s for 20 pages any pictures of what and how they produce.... if not here what you might expect (still not done yet)

View attachment 151102

View attachment 151103

 

[p man]

by the way those are 42 watt soft white cfls rated at 200 watts I think 2800 lums, from menards apx $8.50 each....the other plant is under the 400hps ...trying to get a little out of her on both plants at this point if you guys know what I mean....

 

[Musturd]

Spectrums and Autos ?

Currently using a T5 HO 4ft 4bulb all 6500k, also running 8 23w cfl (4 6500k 4 2700k) My space is 5ft l x 2ft w x 4ft h.
My question is should I go with this or put some red in the t5. I cant really put them in just for flower as I have plants at different stages.
So whats better for the life of an auto, a nice mix spectrum or mostly 6500k with just a lil 2700k. Thanks!

 

[Red eyed c]

I'd say a mix would be better mate,2 red 2 blue would cover the veg and flowering spectrum nicely :smokebuds:

 

[Musturd]

Done Thank You!!