Philips LED
 

Hello,

I am new at growing hydroponically and have been learning from the boards on this site. I would like to ask you guys about the purchase of two lights. I am growing a couple of varieties of microgreens and am trying to choose between:

Philips T8 LED 5000K

https://www.homedepot.ca/en/home/p.l...000837301.html


and the


Philips T8 LED 4000K

https://www.homedepot.ca/en/home/p.l...000789441.html

I have two concerns:

1. Does anyone know if these lights emit the correct spectrum of light for plant growth. I am hoping I won't have to supplement with another light to fill out the Red and Blue.

2. Does anyone know or have a guess at the spread of this light. What area would something like this effectively cover.

Thanks so much guys!

Aaron

Hello Aaron1989,
Use those bulbs just like regular fluorescent T8's. The 4000K, 5000k number is the spectrum itself. The lower the number the closer to the red spectrum it is, and the higher it is the closer to the blue spectrum it is. Blue spectrum mimics bright early summer light, red mimics lower late summer light. In nature the sun's spectrum of light is determined by the suns distance, and position in the sky. During early summer the sun is closer to the earth and higher in the sky. during late summer and fall the sun is farther away and lower in the sky. When the sun is lower in the sky, the sun's rays have to pass through more of the earths atmosphere. That changes the spectrum of light by the time it reaches the earths surface. That's why you get brilliant red sunsets when the sun goes down (especially during fall). That's the point when the sun's rays have to pass through the most atmosphere before it reaches the surface.

https://www.energystar.gov/products/...lbs/color_mood

As for the spread of light from those LED T'8's. Again, like I mentioned, use them just like regular fluorescent T8's. The coverage will be just about the same, and the actual throw (lumen drop off from distance), will be just about the same. Depending on the actual LED's and circuit boards, it might be slightly better than regular T8's, maybe even closer to fluorescent T5's if your lucky. But will be about the same.

Hi GPSFrontier,

Thank you so much, that's exactly the information I needed. I will follow up on this with a little research of my own. I am using standard 20''x10'' trays to grow so I think these lights will have enough spread to cover the area of these trays at about 2ft above.