A BASIC GUIDE TO CFL's

**RedWhiteBlueGreen** · 29-11-11, 08:40 PM

Quick answers for Dan first - firstly, any dual spectrum bulbs emit both the spectrums constantly - they don't "change" themselves according to grow period. I think most dual spectrums work by having half the U-shaped prongs in blue spectrum & the other half will be in the red spectrum, so when u turn the light on the whole bulb then shines out both spectrums at once.

Also, in regards to a PC case grow - u dont wanna veg for too long, if at all, as veg period is purely about growing big & bushy (which is fine if u got the space for it!) but during flowering growth will still occur, just with a portion of the energy put into making flowers. I.e. if say u veg for 4 weeks, then flower for 8, u'll likely end up with a plant approx. 2 - 3ft in height which is too big for a PC case. I'd say give them at most 1 or 2 weeks of 18/6 light as soon as seedling pops up, then switch to 12/12 within the 2 weeks of popping from seed. It will still grow fine but should remain under 1ft and thus fit into the PC case. Also, it may be worth looking at topping it once so that rather than ending up with a tall, christmas tree-type shape, you get it to look more bush-like (short, squat & bushy). Again, this will help it fit in PC case better & also ensure more bud sites get light rather than just the one big main stem.

**RedWhiteBlueGreen** · 29-11-11, 08:57 PM

Secondly, just to add my experience on using CFL's if it helps any interested budget growers.........

I usually do 2 plants a time in old wardrobe painted inside with Brilliant Matt White Emulsion - they get topped once & abit of slight LSTing. I use 1 x 250w Red CFL (cost £44) and 4 x 14w domestic household CFL's (cost 40p! (usually no more than quid each at most tho)).

As soon as the seedlings pop, i put them under 1 x 14w for 1 or 2 days only (they need some light but nothing too strong), then for the next 5 or 6 days, i put the other 3 x 14w's over them.

After 1st week of this, i then put the 1 x 250w over them and arrange the 4 x 14w's around the lower down sides of the wardrobe (the sockets i use for the 14w's have pegs/bulldog clips on them that i clip onto nails in side of wardrobe - this means side & lower branches still get some light). Then this set-up remains for 3 to 4 weeks of veg and then 8 to 9 weeks of flowering.

And finally i got a heavy duty "Plug n Grow" timer that i use (cost £12.95) as i've heard normal timers are safe & fine for CFL's but this heavy duty one just offers abit more peace of mind.

All in all, quite a cheap set-up, and allows u to invest abit more of a tight budget into equally important area's such as quality soil & nutes or higher brand seeds, etc.

**Doc** · 16-12-11, 12:11 AM

Wow, great post thanx pal

**Greeneyedcat** · 16-12-11, 12:31 AM

Great read, thanx!!

**snoopdog** · 04-01-12, 12:59 PM

would i be ok to run my grow on 600w hps right through? or do i need to lower the lighting for vegetation?

**Gheko** · 11-02-12, 10:50 PM

Very helpful. Nice one!!

**MacgyverGrow** · 15-02-12, 05:41 PM

hmmmm very nice got alot of good info about cfl lights!

**dunny27** · 17-02-12, 02:01 PM

thanks for the info just started to grow in a small space this info is invaluable.cheers

**dunny27** · 17-02-12, 02:11 PM

im currently growing in a wardrobe about half a meter wide by 2 meters long ive got a 200 watt blue cfl ,a 200watt red cfl and a250 watt hid light im still vegging at 24 hours with cfls and 12 all together does any one think i should flower now ?(4 plants)