Please help with Fluorescent Light
 

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. :scratchhead::evil::cheer:
Nguyen

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®

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

What is the difference between t8 and t5?

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.

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.:hmm

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.

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.

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!;)