# Are "grow lights" even effective?



## Fortuna Wolf (Feb 3, 2007)

I've been using grow lights in my hydroponics and now that I'm setting up a new aquarium, I was thinking that I should put some grow lights in it, you know, to help the plants out. 
But... are they even worth it? most people here don't seem to use them. I just found this webpage - Aqua Botanic-light bulb comparison
And was very surprised! 
Tell me, is it true? Are those expensive grow lights completely useless? Should I instead be looking for daylight and cool white bulbs, or even 10,000k?


----------



## AaronT (Apr 26, 2004)

Grow lights are effective enough, but the light tends to be unpleasant to the eye. The daylight bulbs will do just as good of a job if you get a quality one.


----------



## Newt (Apr 1, 2004)

You can get 40w gro-lux bulbs fairly cheap at www.saveonlighing.com

and they will do a better job at growing plants but you will also want to mix them with a 5000K light or there abouts to balance out the color of your tank.


----------



## BryceM (Nov 6, 2005)

Quantity is the key when it comes to lighting. Enough of any reasonable specturm will do a fine job of keeping plants healthy.


----------



## Newt (Apr 1, 2004)

True, but bulbs that do not have a tri-phosphour signature have light that will not help plants but will aid algae growth. As amny have pointed out common fluorescents like cool white and warm white have blue and light in their spectral output, but not as intense as grolux and some other tri-phos bulbs.

This is a spectral graph for a GE Cool White bulb:


----------



## ruki (Jul 4, 2006)

I mix grow bulbs with something else. My experience matches what was in Walstad's book. A grow bulb mixed with something else (even cool white!) produced more growth than two grow bulbs or two cool white bulbs.

Mixing something like a 6500K bulb with grow bulb will look good and grow plants very well.


----------



## Newt (Apr 1, 2004)

I agree, Ruki......and it certainly looks better to the human eye.


----------



## Fortuna Wolf (Feb 3, 2007)

I got around to testing a mix together, and yes, it does look better than either to my eye. No clue as to its effectiveness though.


----------



## ruki (Jul 4, 2006)

The experiement Walford's book determined effectiveness by starting out with identical tanks except for lighting and then weighing the plants that were produced.


----------

