Please help with Fluorescent Light - Orchid Board

newflasker · #1 (**permalink**) 10-29-2007, 03:27 PM

I grow my seedlings under fluorescent light: 2 tubes, 24 inches, T8 type, 25 watts, which I buy from Walmart for $10. Everything is OK. Seedlings grow slow but keep growing. Now my bulb are gone so I need to buy new bulbs. I could not find them in my local walmart, homedepot... I surf on the internet and found many T8 with a lot of information which confuse me: cool/warm/bright white..., color: 3400K, 4100K, 6500K.., CRI: 62, 78, 86..., 15Watt, 17Watt,32 Watt..., and price are quite different (a bulb is more expensive than my 2 bulbs and fixture). So what kinds of bulb do I need for my seedlings? Where can I buy cheap source? What does it mean color 3400K vs 6500K, cool vs bright, 15 Watt vs 32 Watt and so on. Thanks for your information.

Nguyen

Ross · #2 (**permalink**) 10-29-2007, 04:05 PM

Why not move to t5? I buy t8 at home depot but, I confess, Most of mine are t5 which I buy locally at cPanel®

Magnus A · #3 (**permalink**) 10-29-2007, 06:55 PM

I would say that
cool/warm/bright white..., is a description in words of how we see the light. warm is more red less blue, cool the opposite and bright I do not know maybe its the closest to daylight. Remember this do not describe the spectra just the apperance.
color: 3400K, 4100K, 6500K.., is the mathematical way to describe the colour of the light, low number "red" light, higher more blue. good value should in MY oppinion be around 5000-6500 K.
CRI: 62, 78, 86..., have not seen this value, do not know!
15Watt, 17Watt,32 Watt... is the power rating of the bulb. I think that the power in Watt is proportionel to the length (not 100% on the last)

/Magnus

I use T5, 54 Watt, 6000K myself

IdahoOrchid · #4 (**permalink**) 10-29-2007, 10:53 PM

What is the difference between t8 and t5?

gixrj18 · #5 (**permalink**) 10-29-2007, 11:53 PM

T5 is smaller than T8. The horticultural T5's (which you would find at a hydroponics store, or on line....not at Home Depot) are made specifically for growing. While they run around $40 each, they are 100 times better than normal flourescents. They use a quarter of the energy of a flourescent, and put out 3-4 times more light. All of it's light is usable spectrum by a plant, unlike the flourescents...no wasted light! You will notice the difference, immediately.....they're expensive, but they're worth it! I have two, I recommend them.

quiltergal · #6 (**permalink**) 10-30-2007, 01:59 AM

I installed 4 T5s about 2 weeks ago and I'm amazed at the difference I'm already seeing in my plants. I have one in sheath with quickly developing buds, another in bud and most of the others are sending up new leads and tons of new roots. I don't know if it's a coincidence or not. Something tells me it's not.

IdahoOrchid · #7 (**permalink**) 10-30-2007, 07:02 PM

I think I would bet on coincidence, Terri. I would think it takes longer than two weeks for a change in culture to have any drastic affect such as blooming, at least for most plants. Your plants color may be quickly affected though.

Ross · #8 (**permalink**) 10-30-2007, 07:24 PM

Quote:

Originally Posted by IdahoOrchid

I think I would bet on coincidence, Terri. I would think it takes longer than two weeks for a change in culture to have any drastic affect such as blooming, at least for most plants. Your plants color may be quickly affected though.

Actually two weeks CAN make a diff! Especially with light. t5's are SOOOO much more better than others that their use will, make a noticeable diff. almost immediately (at least, that's my experience.) I've seen leaves start turning reddish right away.

Lagoon · #9 (**permalink**) 10-30-2007, 08:50 PM

Oh I do believe just 2 weeks can make the difference.
I went from a 2foot T8's to a 4foot T8's in less then 3 weeks and WOW I've seen a change in my own 'chids. They just jumped in growth and I do have sheaths I didn't have couple of weeks back.
Sure it could have been the timing as for the sheaths, but the growth is very noticeable with the new lights.

quiltergal · #10 (**permalink**) 10-30-2007, 09:49 PM

The plant that is in sheath was in sheath at the time I installed the lights, however that sheath sat there and did nothing for at least a month. As soon as the lights went up the buds started developing, and I'm just blown away by the rate of growth. I also have a dendro that previously bloomed in the spring, and showed no sign of blooming, but in the last week it started pushing buds out all over the place. I hope this isn't a fluke and I can look forward to lots more flowering.

I can't really give all the credit to my lights. My culture has gotten lots better over the months mostly thanks everyone here at OB. Maybe it's paying off!