need advice from fluorescent tube growers

I have four plants started in plastic cups. They are with my older plant under 6 23 watt CFL's (6500K). I'm wanting to change my lights. I'd like to install 4 48" 40 watt t-12's. Daylight (6500K) for vegging. Kitchen/bath (3,000K) for flowering. Can anyone tell me if this would be enough light for four plants? I'm working with 4.3'L X 2.5'W X 5.5'H of space. Would it be better to evenly mix the lights rather than switch bulbs? Thanks.

As long as your plants have atleast 50 watts each than you'll be fine.

are you using them strictly for veg or for flower as well. id use 6 just to be certian of it myself. i noticed the results defiantly when i upgraded and added 2 more t12's.

i use 2 red and 4 blue bulbs in veg and the oppisite for flowering with them. but ive upgraded to hps cause flowering with them sucks balls. when flowering you want 2 red bulbs per plant and put them in a box with mylar/white paint to save light. flower them at about 8-9" for best results in my opinion.

Thanks Kochab.

Why is flowering with them so bad?

Mitsu racerX said:

Thanks Kochab.

Why is flowering with them so bad?

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because their light penetration is so weak. its decent if you use a couple per plant, but the more you use the better.
the buds from them are generally smaller than hps. they are best in some cabinet thats big enough to accommodates for flowering plants. it really helps use all the light they give off which is important. keep the bulbs no more than 3" inches away from plants canopies.

no prob to who ever left the rep+

kochab said:

no prob to who ever left the rep+

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i think it was me.

Well, I grow 8-12 1ft Indica/Sativa mixes under 2 4ft 40w T5 fluorescents. I even flowering under them. But they are right, the light penetration sucks, you need something else to help out with side-lighting lower nodes. You can do a nice ScROG with the T5's though. And if your not careful and diligent your plants will stretch.
Heres my setup.

Give them as much light as you can and always mix the lights if you can.
I have tubes and a hps and i think i get great results from mixing red and blue all the way through veg and flowering

W33D said:

Well, I grow 8-12 1ft Indica/Sativa mixes under 2 4ft 40w T5 fluorescents. I even flowering under them. But they are right, the light penetration sucks, you need something else to help out with side-lighting lower nodes. You can do a nice ScROG with the T5's though. And if your not careful and diligent your plants will stretch.
Heres my setup.

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looks pretty good for what you are working with. and if those plants pictured have never had anything but 2 t5's...... on them at a time id say it looks like a pretty decent grow. slightly streched but thats to be expected with tube lights and plants from seed.
its much easier to flower clones under these as the canopy stays about a constant level the whole grow because having uniform dna means that the clones will grow most exactly alike with small minute differences.
~just a small tip for any newbs using or getting started with these lights.~
and i never said they wont flower......just since i have an hps now, adn that surpasses the tubes by 150%+.
but ereyones gotta use what they gotta use.

i have four medium size plants..as of now i have 2 13watt cf's and an old desk lamp that has 2 23watt tubes about 10inches long.....i also was woundering if anybody knows the best way to maximise yields?

Youll want to get rid of the T12 as those are the lest benfitial of the T lighting.For the same price get T8 light structures.You can use them to veg on 24 hours a day but you will need a good group to pull off a good flower with them. I use T8 to veg about 18 plants per 4 four foot light setups.A commercial 4 tube 4 bulb setup with a added cord is about $40 with bulbs so if you wanted ot do say 8 plants youd want about 6 of these setups in both bulb colors so it gets the right spectrums.here a picture of some plants under T8 lights and then 3 days under 1000 watt mh.These are at 26 days old in the last pictures in miracle grow moisture control soil with no nutes just ph water under 24 hour lights on..

Yeah I agree with what everyone is saying here. I presently have about 5 plants under 4 cfl's together but I have not started flowering with them. i have flowered with cfl's very successfully but had them hanging everywhere.

I would try and add at least 2 more bulbs BUT I would put them closer than 3 inches. I have mine almost touching. The damage to the leaves is so minimal compared to the benefits.

I am getting a new 1000 watt MH light this morning though

here's a pic.

What I do to maximize my yield is I start training them. I bend the branches down gently and grdually so that then you get shorter plants with colas growing upwards along branches. I top them after the 5th node and I also start loosely tying back leaves to get better light inbetween the branches. This has worked good for me in the past.

Good luck

biglew said:

i have four medium size plants..as of now i have 2 13watt cf's and an old desk lamp that has 2 23watt tubes about 10inches long.....i also was woundering if anybody knows the best way to maximise yields?

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biglew said:

i have four medium size plants..as of now i have 2 13watt cf's and an old desk lamp that has 2 23watt tubes about 10inches long.....i also was woundering if anybody knows the best way to maximise yields?

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get a hps or more flo's.

Ushio makes really nice high output T10's Businesslights.com sells them. This is a 5000K lamp that will work really well for both veg and flower. I like to use 1 tube per square foot. I have a 24 square foot garden and I'm running with 20 tubes.
5000K fluorescent is the best overall lamp. I've used K&B but I find I need a to mix a few higher temperature lamps to get enough blue light. Ushio T10's are very high in lumens and perfect for growing. They fit any fixture that is designed for T12's.

Object 16, about how many plants is that? From what you saying if I have 9 sq ft, then I'll want to use 8-10 tubes (I'm going with the 2 tube fixtures). Right?

I'm using shoplight fixtures that are 7inches wide. If you line up your fixtures so that you get about 4 lamps per foot of width or so, then, that's
about 40 watts per square foot if using T12 or T10 lamps, or about 32 watts per square foot with T8's (normally driven), or about 50 watts per square foot if you overdrive the T8's (but that is another thread). That amount of wattage is just about right. If your garden is 3 feet wide, I'd use about maybe five fixtures, total of 10 lamps. To improve the reflector, you can either use double sided indoor carpet tape and mylar (kind of a two person job, in my experience. Lay down a centre strip of tape, glue the centre of the mylar down, and then use smaller pieced to hold the side part of the mylar to the side part of the reflector), or cut the right width, and SLIDE the mylar in between the tubes and the fixture - this works with shoplight type fixtures quite well, makes sure all the light goes down.

I re-measured. Width is a little shy of 2 ft. So I figure 3 fixtures (6 lights). Maybe one or two kind of on the side(s) later to help the lower branches.

You can still have a better more robust grow if you top them and bring the lights closer.

With cfl's the light almost have to touch.
3 or 4 inches away is too far.

After topping them you start making the branches stonger and bring them down lower by bending them gently and gradually. It works incredible well.

W33D said:

Well, I grow 8-12 1ft Indica/Sativa mixes under 2 4ft 40w T5 fluorescents. I even flowering under them. But they are right, the light penetration sucks, you need something else to help out with side-lighting lower nodes. You can do a nice ScROG with the T5's though. And if your not careful and diligent your plants will stretch.
Heres my setup.

Click to expand...