After researching many posts it is appearant to me that each bulb gives out about 5,000 lumens and they do not add.

So you are in fact giving a 8 square foot space 5,000 lumens and not 40,000 lumens as people state.

Good luck with your experiment though.

The huge advantage of T5 is little heat. Though it will cost more to run. The spectrum Is much better though with MH/HPS combo.

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That is not true. A lumen is the amount of light 1 small wax candle emits.
So if you have 5000 candles in a room, and you add 5000 more, it will be brighter. Also understand that plants can "see" light that the human eye can't. See below. If that were true there would be no point to using more than one bulb

Attached Images

	Plant-Human-Eye-Response_01.jpg (48.2 KB, 4 views)
	Plant-Human-Eye-Response_02.jpg (41.9 KB, 4 views)

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To see my Growroom and Plants click this link
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Actually, plants absorb part of the visible spectrum of light that we can see. They cannot actually "see" and cannot see light in the green spectrum which is why some growers use these types of lights to maintain plants in the darkness during flowering.

The brightest point of a 4' T5 luminescent tube is 5,000 lumens brightness. The brightest point of a 400 HPS is approximately 55,000 lumens.

Now, I will admit that I am not even a grower yet but I have spent many hours reading this and other websites in preparation to grow. So, I will ask you this... How many serious growers have you read about swearing by T5 Flourescent lighting for the flowering stage of growth that have been using it consistently for 3 or more grows?

T5's and other CFL flourescent seem great for germination and early growth. It can be argued that they are even good for vegetation. However, they do not compare to other lighting when flowering.

You can use them if you are doing a stealth grow where heat or ventilation is an issue but ultimately you will get less yield and less dense quality bud.

To answer your question, HTG has some really good prices and they have an 8 bulb 4' for 270.00

High Tech Garden Supply

One bulb is 5000 but she wants to use 8. That will give her 40k lumen.
Me personaly, I will only use MH/ and HPS. The main advantage of T5 is it produces far less heat, therefore you can place it closer to the plant and grow in smaller spaces. Also you need not worry about vented refelectors, and extra high cfm fans. I know a few, but they are few and far between. Truth is the absolute advantage of MH/HPS is how many Lumens you get per watt.

My current system is 2 400w mh and 2 600w HPS with Lumatek ballasts that produce 20% more light using 10% less energy than traditional ballasts. My Total lumen is 307,200 in a 8X4 (32 sq ft) area Thats 153.6 lumens per watt and 9600 lumens per sq ft.

I know they can't "see". Yes you are right they don't use green light because it is the color that is reflected off the plant (hense you see the plant is green)

Personally I don't think she should get the T5, but I don't know all about her grow room. It may be the best thing for her job. I just wanted to make sure she had all the information before make the decision.

P.S. if you look at the attached thumbs above, it shows what the human eye can see compared to plants

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To see my Growroom and Plants click this link
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Ok, if she is sure that is what she wants send her to HTG. I dont think you are going to get much cheaper than that.

She could also buy 4 4' 2 bulb models for 70.00 each which would allow for alot more versatility at about the same cost. It would put out the same number of lumens.