# T5 vs. 40 W Fluorescent???



## zephyrusjohn (May 15, 2008)

Hi group, looking for some input on a new basement setup for Paphs. I currently grow in a 24' x 72' greenhouse, 14' gutters. It is big and airy, and of course subject to extreme environmental fluctuations. A basement room is appealing in many respects, so I am solicting your input!

In a dedicated basement with 8' ceilings, I am considering a two shelf system. 400W metal halides hanging from the ceiling, with mature/largish Paphs/Phrags underneath, ~4' or more from the bulbs. Underneath the table will be compots and 2 1/4" pot seedlings. 

What is the feeling on lighting underneath the bench? 40W fluorescents, relatively close to the plants, or T5's a little bit further away? (The latter option is slightly more appealing as it gives more clearance for watering, etc.)

Thanks in advance for your input!

John


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## cnycharles (May 15, 2008)

I know t8's use less power than t12's and you get more light. From that I would assume that the t5's use even less power? Also the heat given off might be an added factor as I think my electronic t8's as likely would t5's give off slightly less heat. So, you might have to have the fixtures higher but you would likely use less electricity for the amount of light and maybe slightly less heat. One thing is if you wanted to get creative with the type of bulbs you wanted to use, the high intensity t5's might be more expensive, though issues like heat, cost and all would need to be researched


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## Candace (May 15, 2008)

How are you going to manage watering in a 2 shelf set up? Since water dripping through to the bottom would spread pathogens to plants on the bottom and fry your lights? I'm assuming trays with tubing to drain away water or something like that?


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## cnycharles (May 15, 2008)

I have plants on rolling carts from work (boss told me it was okay to take them) with shelves; can just use a few layers of heavy plastic and some fencing material around three sides, on the drain side have a piece of rain gutter catch the runoff and into a downspout catcher, down into a tub in the bottom shelf. Old waterbed material and/or the liner from said waterbed works well and resists punctures. Can keep a decent amount of water below the plants and have a grid on top so that it catches water and provides some humidity, as long as you keep plastic around the cart/shelves. Also have a humidifan blowing air up into the shelves


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## GaryB (May 15, 2008)

cnycharles said:


> I know t8's use less power than t12's and you get more light. From that I would assume that the t5's use even less power?



4" t12s are 40W; 4' t8s are 32W; 4" t5s are 54W. Lumens per Watt are about the same for t8s and t5s.

I still think that t8s are the most cost effective choice.


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## GaryB (May 15, 2008)

Candace said:


> How are you going to manage watering in a 2 shelf set up? Since water dripping through to the bottom would spread pathogens to plants on the bottom and fry your lights? I'm assuming trays with tubing to drain away water or something like that?



I have a basement grow room with 2 level rolling benches. The top tray lined with plastic and a plastic support grid holds the plants above the water. I don's have a drain; the water just evaporates and help keep the humidity up.


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## Candace (May 15, 2008)

Neat ideas you two.


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## cnycharles (May 15, 2008)

GaryB said:


> 4" t12s are 40W; 4' t8s are 32W; 4" t5s are 54W. Lumens per Watt are about the same for t8s and t5s.



okay, that partly explains why my supervisor had to give up his excellent reef tank; he said the high intensity lights were bankrupting him (probably t5's)
if you are going to have slipper compots and seedlings under the bench, do you think it would be overkill having t5's? I wouldn't think you would need that much light, and for the cost t8's would likely give you the best light for the price of bulbs and electricity


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## paphreek (May 15, 2008)

If you are only going to grow compots and small seedlings under the shelves, the light requirements will be less than for blooming plants. I would go with the most economical choice. I would also add an HPS bulb for the larger plants on the top shelves to aid in blooming.


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## fundulopanchax (May 16, 2008)

I use T5s in my basement setup. For adult Paphs and Phrags and Cyps they are about 18 inches above the tops of plants. For seedlings, I tried them 24 inches above the flask tops and they fried the flasks. I use 40 watt for flasks or the lights have to be too high above - for T5 about 30 inches - these lights are BRIGHT!

Ron


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## littlefrog (May 16, 2008)

I just built two 'grow racks' for my basement room. I ended up using 18 four foot fixtures. Walmart (MallWart), although I hate shopping there, has the best price on T-8 fixtures. $8.32. I like T-8s. The output is probably better on the T-5's, but even wholesale the fixtures cost a whole lot more.

In my T-8 fixtures I put a new bulb from Phillips. They are 25W instead of 32W. The light output is slightly less, but for what i'm growing here (mostly foliage plants for terrariums) it is fine. Would be good for paphs too, and I'm planning on putting my compots and liners out in this system if I can build a few more racks. The bulbs (which I can only find at the Home Despot) cost a bit more. $3.50 each and you have to buy them in packs of 10. But with the energy savings and the long life of the bulb, I think it is worth a bit more. I like the way the light looks, too.

I could probably take pictures of the racks if there is sufficient demand... I'm on dialup all the time now, so I avoid them when i can.

Rob


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## Corbin (May 16, 2008)

"I know t8's use less power than t12's and you get more light." Charles

"4" t12s are 40W; 4' t8s are 32W; 4" t5s are 54W." Gary

I have pasted a couple statements here because I am confused. Is not the amount of light put out by a bulb related to the watts? Don't 40W t12s put out more light than 32W t8s? 

I use t12s on my light stand and seem to have all the light I need. Things are growing well and blooming regularly. You can buy 4' t12 fixtures for under $10.00 and you can get the bulbs for under $2.00.


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## GaryB (May 16, 2008)

Corbin said:


> "I know t8's use less power than t12's and you get more light." Charles
> 
> "4" t12s are 40W; 4' t8s are 32W; 4" t5s are 54W." Gary
> 
> ...



There are small differences in efficiency:
32W T8 - 2800 Lumens (87.5 lumens/Watt)
40W T12 - 3000 Lumens (75 lumens/Watt)
54W T5 4800 Lumens (89 Lumens/Watt)

This also assumes electronic ballasts. The older magnetic ballast consume more power reducing the efficiency and increasing you cost to operate.

I buy T8 fixtures at Home Depot for about $8 and T8 bulbs for $3 each. The t5 stuff is still too pricey for me (although prices are coming down) ; most place seem to list t5 bulbs for $10 or more. Plus the fixtures are more expensive. 

I am also doing some testing with ICECAP ballasts and overdriving the t8s to about 80W each with increased light output. The ICECAP ballast design is supposed to be able to overdrive the bulb without significantly shortening its life.


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## Corbin (May 16, 2008)

thanks


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## Ernie (May 17, 2008)

T5s are great and energy efficient, but startup costs are very high. All T8s and T12s are NOT created equal! There are some 40w tubes that give MORE output PER TUBE than equivalent 32w T8. Learn to read the package to know what you're buying. Ask yourself if you care about lumens per watt or lumens per tube. If you need 5 T8s to get the same output as 4 T12s (not saying this will always be the case), it's more energy and cost efficient to go with the T12s. Again, this will all depend on the tubes available to you. 
That being said, if I was independently wealthy, I'd use T5s. Like all technology, the price on T5s should come down over time. 

-Ernie


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## Sirius (May 18, 2008)

I have seven t5 fixtures. Bulbs cost me $7.00 a piece. However, if you want to grow light loving species, they are the best option without going HID. I also grow my plants 10" away from the bulbs. No need to have the plants almost touching the bulbs in order to get the right light levels. 

They may be a larger investment up front, but you use them for years. Divide the cost out over the length of use and you end up paying pennies a day for any light equipment. It's all about perspective.


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## Roth (May 18, 2008)

The lumens output are not that important. The whole spectrum of the bulb is however important, where are the peaks, and what is the output for tghose peaks. I think that quite a lot of time we try to give the plants as much light as possible, which is a very big mistake. The 'plant engine' can whitstand some boost, but not that much.

You can download here :
http://www.floricultura.nl/page.asp?id=257060&pid=3280&mid=5167

Of course it tells us bout the HPS, but the crazyness about getting a "lot of light" went down when cultural problems showed up in the Netherlands. Discussing with one dutch grower who had such a high power setup, he said that at first he was happy that he could apply more fertilizer ( because the plants were a little bit deficient with that high light output), and afer 2 years he realize first that some varieties did not like the extra lighting, and second that the plants were, in fact, not growing faster. He had to take measurements and weighting of the plants, as well as checking the time from plug to blooming size. Apparently the plants grow initially much faster under high light intensity, but under Liebig's law, here the limiting factor is the speed absorption of some nutrients. 

So the plant grows faster for a couple weeks/months, then slows down to pick up deficient nutrients, then faster again. One way to overcome the problem has been designed in the Netherlands by one nursery with phalaenopsis, they have injectors with a needle in the base of each of their plants. That's pretty crazy to see that in fact.

I bloomed rhyncholaelia yearly under a 2 tubes fixture TLD 36w/33 ( the cheapest tubes you can find), without any other source of light, so this should tell something...


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## Yoyo_Jo (May 19, 2008)

I have 2-tube fixtures with T-12 bulbs; one warm, one cool. Both 34 W, the warm is 2750 lumens, the cool is 2650 lumens. Am I wasting my time trying to grow orchids under these?  I don't really have room on the shelves to have 4-tubes over each shelf. I'm also not trying to grow high light plants; everything I have is low to medium light.


Joanne


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## Yoyo_Jo (May 20, 2008)

Bump. 

Okay, the silence is deafening... 

Still wondering if two-tube T-12's give off enough light to grow orchids under...(oh please please say yes...)


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## SlipperFan (May 20, 2008)

Yoyo_Jo said:


> Bump.
> 
> Okay, the silence is deafening...
> 
> Still wondering if two-tube T-12's give off enough light to grow orchids under...(oh please please say yes...)



Depends on the orchids. Cattleyas, no. Most Paphs, Phals, yes. Two side-by-side fixtures with two tubes each should be OK for most Phrags. IMO


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## cnycharles (May 20, 2008)

you should be able to grow low-light plants with that setup. I was able to flower a cattleya walkeriana under a shop light though it was 40w cool bulbs. the leaves were directly under the bulbs near the middle of the fixture. I have a brassavola nodosa now that grows under a two-bulb 32w t8, grows and flowers. if the plant likes cool and medium light then you may not be able to get away with it almost touching the bulbs as the plant may get too warm. I did have better luck flowering many phal species in a south window shelf after I added another shoplight which in effect made it a four-bulb fixture plus some sunlight during certain seasons


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## Ernie (May 20, 2008)

Yoyo_Jo said:


> Bump.
> 
> Okay, the silence is deafening...
> 
> Still wondering if two-tube T-12's give off enough light to grow orchids under...(oh please please say yes...)



Sorry, I'd have to say no unless you have some natural light too. My personal experience is four, 4 foot T12s or T8s (40 or 32 w, respectively) is about the minimum one would want to consider for flowering plants. 

-Ernie


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## Yoyo_Jo (May 21, 2008)

I was doing the math, and if I assume the width of the two-tubes are roughly 1/2 foot and the tubes are 4 feet long, that's 2 square feet of light area under one two-tube fixture. The total lumens of light from the tubes would be 2650 + 2750 = 5400 lumens. 5400 lumens divided by 2 square feet = 2700 lumens/square foot = 2700 foot-candles, which doesn't sound too bad. However, that would also mean the orchids would have to be crammed directly under the 6" width of the tubes to be exposed that that amount of light and that doesn't appeal to me at all.

I shall proceed to plan B which involves inspiring my dear hubby to figure out how to get two two-tube fixtures to fit side-by-side above my growing shelves...


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## GaryB (May 21, 2008)

Yoyo_Jo said:


> I was doing the math, and if I assume the width of the two-tubes are roughly 1/2 foot and the tubes are 4 feet long, that's 2 square feet of light area under one two-tube fixture. The total lumens of light from the tubes would be 2650 + 2750 = 5400 lumens. 5400 lumens divided by 2 square feet = 2700 lumens/square foot = 2700 foot-candles, which doesn't sound too bad. However, that would also mean the orchids would have to be crammed directly under the 6" width of the tubes to be exposed that that amount of light and that doesn't appeal to me at all.



Your math is good, but the assumptions are not. Reflectors don't reflect 100% of the light. And is spreads out as it moves away from the tubes further reducing the intensity. You may get 2000+ fc 6" directly under the tubes, but near the edges of the 2' wide space you will be under 1000 fc.


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## Yoyo_Jo (May 21, 2008)

Thanks Gary; I do remember reading elsewhere that the light intensity decreases dramatically away from the bulbs; bottom line is that I'm convinced that the two-tube set up is not going to be sufficient light for growing orchids. On to plan B...:evil:


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## practicallyostensible (Aug 22, 2008)

bump:

I have 4 bulb T-5's and need new lamps is it better to use 3000k or 6500k?


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## swamprad (Aug 22, 2008)

I use half of each type, so the plants get both the growing spectrum and the blooming spectrum.


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## practicallyostensible (Aug 23, 2008)

swamprad said:


> I use half of each type, so the plants get both the growing spectrum and the blooming spectrum.



okay, thanks for the info


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## Yoyo_Jo (Aug 27, 2008)

When the hubby was picking up my new 4-bulb T8 light fixture from our local building supply store today, he found they only carried T8 4100 K. Will these give me the right light spectrum to grow orchids?


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## Kyle (Aug 27, 2008)

Natural sunlight is around 5500 K. I try to use as close to that as I can find. I switched to 100% flourescents this spring. T5's and 200W CFL. Everyting is growing great. The best I could find is 6000K. Its the closest to full spectrum as I could find.

4100K is OK, but its on the end of the spectrum that produces vegitation. A mix would be best.

I like my full spectrum - or close to it- becasue everything looks (colorwise) as it should. Good for looking at flowers, but also judging health by leaf color.

Kyle


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## Yoyo_Jo (Aug 27, 2008)

Thanks Kyle, I'm going to go check out some other stores for bulbs with a higher color temperature.


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