T 5 fluorescent light advice

[Spanky]

I am tired of adjusting 8 CFLs every day during veg. I was thinking it might be easier to get a single 2 ft, 4 bulb fluorescent light. I only grow two plants at a time and always top to keep a low flat canopy. I have an LED that I will continue to use for flowering.

Any suggestions on a good one to purchase? From where? Is this big enough for two plants? I know I will have to check regularly to be sure plants don't grow up into the light. Any other thoughts? I have read the tutorial on CFLs vs. T5 but I don't recall seeing a recommended brand.

Thnaks!

[DoctorJohnson]

Well you can always buy the old standard Gro Lux tubes. There are probably other horticultural tubes out there as well. Any tubes should work though. I would go for a cool white, about 6500K or 5000k.

The problem with tubes vs CFLs is that while you can and should get the CFLs right up next to the plant, with a tube much of it is going to be farther away, up to 12" away with a 2-footer, no?

I have started using household LED light bulbs with the bottom half of the plastic globe cut off using a cutting disk. They give concentrated light of the correct spectrum (again, I recommend 6500K) and are not hot.

[Spanky]

Thanks, I will check them out. If they are 12 inches away, will they be getting enough light? Does it matter what wattage they are?

I didn't know you could do that with regular LEDs. We have them all over the house. When you say cut off the bottom half, do you mean the part that is furthest from the socket? I am not sure if our bulbs are 6500 or 2700 or other. Some are yellow, some blue more like daylight. I will have to see if they give that info on the package. Also, go for the highest wattage? How far do you keep these from your plants. I know every manufacture of traditional grow LEDs have different height suggestions.
Do you get better yields with this lighting?

Thanks!

[DW2]

Dr. Johnson, Are you cutting off the large part of the globe (the part furthest from the screw base)? And what wattage are You using? I'm currently using 55 watt spiral CFL bulbs and have a plan to change to using regular household 23 watt spirals (100 watt equivalent), but I am finding it harder to finding the CFLs (most likely due to the mercury content). I was thinking of using those screw-in LED bulbs with multi spectrum LEDs in them, but I do not know if they are worth it or not.
Your input would be appreciated. Thanks.

[Newf]

I have used an off the shelf T5 light fixture from Home Depo with two 14-Watt 6500K T5 fluorescent bulbs (about $50) which has worked well for seedlings and early veg for a couple of plants. You can keep it right up against the plant. It has a clear acrylic lens so the plant don't actually touch the bulb. It is easy to adjust the height. When Doc Johnson says 12 inches away they mean that if the center of the tube is touching the main cola the ends of the tube will be 12 inches away. For flowering you say you already use an LED light. Why not get a second LED like the VIPARSPECTRA Reflector-Series 300W LED. It is about $79 on Amazon and will give you better results. You can use just the Veg setting. You do need to be careful about distance, though, with LEDs. If you don't have much overhead room you need to train your plants short or keep to the T5 lights.

[DoctorJohnson]

> If they are 12 inches away, will they be getting enough light?
When I say 12 inches away, I mean the even a fluorescent tube that is just a few inches from the plant will be 12" away at its ends. That's the disadvantage of tubes over CFLs--the light from a 2' tube is spread out over 2'!

> Does it matter what wattage they are?
Well, yeah, of course, but I don't think you have a lot of choices. A cheap lux meter will tell you a lot. Lux meters for white light (including white-ish light from CFL, HPS, etc) are kind of falling out of favor because they are not useful for measuring the "blurple" light from LED grow lights, which require a more expensive PAR meter, but I use my cheapy Amazon LUX meter all the time to measure and compare and adjust light levels in my grow. Instruments are good!

> When you say cut off the bottom half, do you mean the part that is furthest from the socket?
Yes. You don't have to cut off the bottoms. They work just fine with the diffuser bulb in place, but just as with CFLs, they need to be very close--inches away--to be most effective. When you cut off the diffuser bulb they become much more directional.

> I am not sure if our bulbs are 6500 or 2700 or other. Some are yellow, some blue more like daylight. I will have to see if they give that info on the package.
As Nebula says, the exact spectrum/color doesn't matter as much as just having enough (lots of) light. The bulbs are usually labeled with watts, lumens, and color. Yellowish is 2700k (warm white), 5000 is white, and 6500 is cool white.

> Also, go for the highest wattage?
Go for the highest wattage/lumens you can get would be my recommendation. A 14 watt LED light bulb works well. A 23 watt is even better.

> How far do you keep these from your plants.
With the tops cut off and aluminium foil reflector cones that are 4" wide at the base to help restrict the light to the area of interest, I keep mine about 6" away.

> Do you get better yields with this lighting?
This is in my opinion still best for starting seedlings up to about 2 or 3 weeks of age or for beginner setups. I kept adding to my bulb and socket collection until now I have nine, so I can do a tolerable SCROG with them, but just one small HPS or a 300 watt LED grow light would require less fussing.

LED light bulb with the diffuse globe removed

[steve]

"galaxyhydro" makes a very good low coat LED (many choices/stlyes) for cfl bulbs look at 1,000 bulb.com (they have 100(= to 400 watt) watt to 200 watt = to 600 watt spiral with built in ballast and only takes 100 watts for one ans 150 watts for the 600 watt company worth a look

[Spanky]

Sounds like t5s aren't all that great. Especially if they can only be used in early veg.

As it happens, I have a Mars Hydro 48. Each Led is 5 watts. They say that is a total of 240 watts.. Thing is, I am only using some of the LEDs during veg and all for bloom. I wasn't sure this was powerful enough to use alone so I supplement with eight 23 watt 6500 CFLs in veg and 8 23 watt 2700 CFLs in flower. Do you think just this led is enough for the full veg period? I am not experienced enough to test it out for a full veg cycle on one of my precious seeds!