Fluorescent Lighting~ About T-5's and T-8's - GreenPassion.org - Dedicated to Medicinal Cannabis Cultivation and Education

jangel · #1 (**permalink**) 09-19-2009, 01:22 PM

Quote:

Originally Posted by The Corsican

Hi Jangel,

What do you think of T8 lighting? They look very similar to T5s and are easy to find at the large home improvement stores. The T5s seem to be a little harder to find.

What are the differences between the two?

Thanks,

-the Corsican.

I have both. I use T-8's for my clones and seedlings. Here is something I found on the net:

What are T5 Lamps? | T5 Fluorescent Systems | Lighting Answers | NLPIP

What are T5 lamps?

T5 lamps are fluorescent lamps that are 5/8" of an inch in diameter. This report discusses only linear T5 lamps. Differences in length and socket pin design versus conventional fluorescent lamps prevent any problems with electric circuits or human factors. This section focuses on the physical characteristics of T5 systems compared with T8 systems.
What does T5 mean?

The "T" in lamp nomenclature represents the shape of the lamp-tubular. The number following the "T" usually represents the diameter of the lamp in eighths of an inch (1 inch equals 2.5 centimeters). T5 lamps have a diameter equal to 5 times an eighth of an inch, or 5/8". These lamps are approximately 40% smaller than T8 lamps, which are one inch in diameter, and almost 60% smaller than T12 lamps, which are 1½" in diameter. Figure 1 shows diagrams of lamp ends of T5, T8, and T12 lamps. Figure 1 also shows that pin base type of T5 lamps is different from that of T8 and T12 lamps. T5 lamps have a miniature bi-pin base while T8 and T12 lamps use a medium bi-pin base.

Figure 1. Lamp Ends

Are T5 lamps the same length as T8 lamps?

T5 lamps are slightly shorter than T8 lamps and therefore cannot be used as replacements for the larger lamps. Some luminaires, however, can be made to accept either T5 or T8 lamps by changing the sockets and ballasts. Table 1-1 compares lengths of T5 lamps with T8 and T12 lamps.

Select the measurement(s) to be displayed: Metric English Table 1-1. Linear Lamp LengthsNominal Length (ft)Actual LengthT5 (mm)
T8 and T12 (mm)
25495903849895411491199
Table 1-1. Linear Lamp LengthsNominal Length (ft)Actual LengthT5 (in.)
T8 and T12 (in.)
221.623.3333.435.2445.247.2

T5, T8, T10, and T12 Fluorescent Grow Lamps

Fluorescent lamps are designed for all plant growth stages. T8 and T5 fluorescent lamps are available in 3000° Kelvin for flowering and fruiting stages, 5000° Kelvin for vegetative growth, and 6000° Kelvin for full spectrum growth. 4 foot T10 5000K fluorescent lamps replace standard T12 lamps, and T12 fluorescent lamps are availabe in 2ft, 3ft, and 4ft lengths. Fluorescent lamps produce very little heat and may be operated within 4 inches above the plant canopy.

jangel · #2 (**permalink**) 09-19-2009, 01:40 PM

The improvements of T-5 over T-8, which were not previously possible (i.e. you could have had a HO T-8)

Smaller diameter means 5% more efficiency that T-8
rated for 35*C (100*F)
Lower Mercury content 3mg vs. 15mg per 4' (1.2m) tube
Higher color rendering Index Standarized @ 85+
lower lumen depreciation (because of lower mercury)
Longer life span (because of lower mercury)

I suspect the gas pressure and content is the the key in having efficiency tuned for higher temperatures. Also the lower mercury content makes the bulb function differently... Mercury functions as a vital low pressure gas which allows ignition of the bulb... Without mercury, none of this would be possible (at low pressures). They have gone to great lengths in HIDs (MH and HPS) to eliminate Mercury, and as you can see in the link below (if interested) how they compensate for this lower mercury level. Many HIDs still do have Mercury.

T-5 are not as much of a radical departure, as a refinement of T-8 lamps, the smaller diameter is not the main focus, even though they look very cool!

The T5 Fluorescent Lamp: Coming on Strong

"One result of enclosing a smaller lamp with a relatively high output in a smaller fixture is heat — and lots of it. For that reason, the T5 lamp provides peak light output at 35°C (95°F) air temperature, whereas the T8 and the T12 lamp provide peak light output at a 25°C (77°F) ambient air temperature."

And my favorite site about T-5 lights is below:

Introduction | What are T5 Lamps? | T5 Fluorescent Systems | Lighting Answers | NLPIP

This is not my work, but found at this site...

Do your t-5 bulbs get hot? - Orchid Board - Most Complete Orchid Forum on the web !

Wiki floros

jangel · #3 (**permalink**) 09-24-2009, 02:25 PM

I had a good Question from the Corsican and thought I would add this info to it's own thread to help us all with these questions. Please add any info you come across to this thread. This is how we all learn and gain wisdom.

I have been using fluorescents since I started indoor growing. First cfl's and then T-8's and finally a small set of T'5's. I find them just wonderful to grow with and just the ticket for starting clones and seedlings as well as vegging plants under. They are cheaper to run than other types of lighting, and work extremely well. Wonderful to use if you have a small space and air exhaust is a nightmare. They run pretty cool and the plants can grow right up into the bulbs and seldom get scorched.

I do know some members also use T-12's. I have heard they have just the same success as with T-8's.

Please add to this folks.

Peace

Colamaximus · #4 (**permalink**) 09-24-2009, 04:43 PM

This has been very useful for me, for I plan to use the T5's in my first indoor grow for veg. This has answered the questions I had on the differences between T5's and T8's. Thank you jangel...for once again you have answered one of my many questions...Peace

Deb-HAS-grn · #5 (**permalink**) 09-24-2009, 05:34 PM

Yes thank you Jangel,, this is very helpful for me also... Great stuff

Dez · #6 (**permalink**) 10-17-2009, 11:58 AM

I grew with a T5, check my journal, and the results, not bad. imagine what an experienced grower could have achieved :

http://www.greenpassion.org/f16/rook...-journal-9921/

Here is where I got it, and no I do not work nor know anybody from this company.

MONSTER T5 FLUORESCENT PLANT GROW LIGHT REPS 400 hps mh on eBay.ca (item 220483964729 end time 21-Oct-09 16:47:17 EDT)

I am curious about LED lights myself, but from my research on this forum, it seems there are scammers and legits, I just can't quite figure out who's legit and isn't so I'll stick with my T5 for now until the LED technology becomes more prevalent.

Dez · #7 (**permalink**) 10-17-2009, 12:04 PM

I wonder, would a couple of these be a good addition during flowering?

BLOOM hps & GROW mh FLUOREX COMPACT FLUORESCENT LIGHT on eBay.ca (item 220471721174 end time 25-Oct-09 11:32:13 EDT)

jangel · #8 (**permalink**) 10-20-2009, 03:28 PM

Quote:

Originally Posted by Dez

I wonder, would a couple of these be a good addition during flowering?

BLOOM hps & GROW mh FLUOREX COMPACT FLUORESCENT LIGHT on eBay.ca (item 220471721174 end time 25-Oct-09 11:32:13 EDT)

You can try it Dez, but I would worry about the heat those babies would produce. If you feel your ventilation is sufficiant, then go for it, sweetie.

They look good. Just make sure you do not need a different fixture for them as well. Many need a mogul light fixture, for the larger cfl's. so do your research!

Peace