6500k Myth?
Planted Tank Forums
Your Tanks Image Hosting *Tank Tracker * Plant Profiles Fish Profiles Planted Tank Guide Photo Gallery Articles

Go Back   The Planted Tank Forum > Specific Aspects of a Planted Tank > Lighting


Reply
 
Thread Tools Display Modes
Old 12-22-2013, 05:25 PM   #1
Deano85
Algae Grower
 
PTrader: (0/0%)
Join Date: Nov 2011
Location: Alberta, Canada
Posts: 120
Default

6500k Myth?


From the beginning of time we were told to get optimum plant growth you need you use 6500k bulbs. As long as the plants gets enough from the blue and red spectrum what does it matter? Does anyone know of any experiment done with identical tanks one with warm and the other cool white bulbs?
Deano85 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-22-2013, 05:28 PM   #2
Deano85
Algae Grower
 
PTrader: (0/0%)
Join Date: Nov 2011
Location: Alberta, Canada
Posts: 120
Default

According to this warm white cfls actually produce a greater par value.


Deano85 is offline   Reply With Quote
Old 12-22-2013, 09:01 PM   #3
Hoppy
Planted Tank Guru
 
Hoppy's Avatar
 
PTrader: (74/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 18,659
Default

Maybe someone has done the testing to say that one color temperature is better than another, but I don't remember ever seeing a write-up of that testing. It is still a very good experiment to try, but a very time consuming and difficult one to do well. I keep thinking I might try it some day, but that day hasn't come yet.
__________________
Hoppy
Hoppy is offline   Reply With Quote
Old 12-22-2013, 10:33 PM   #4
Indychus
Planted Tank Enthusiast
 
Indychus's Avatar
 
PTrader: (8/100%)
Join Date: Feb 2013
Location: Irmo, SC
Posts: 645
Default

6500k is the color temperature of natural daylight. People suggest using 6500k because the sun seems to do a pretty decent job of growing plants. I'm sure other color temperatures will work fine, but there's not much reason to experiment with what is the most effective when millions of years of evolution have tuned plants to respond to the sun. Duplicating the sun's output is obviously the best approach.
__________________
The Fraternity of Dirt
Check out my open-source Arduino-Powered Light Controller Guide for Current LED+ and other IR switchable lights.
Indychus is offline   Reply With Quote
Old 12-22-2013, 11:08 PM   #5
Deano85
Algae Grower
 
PTrader: (0/0%)
Join Date: Nov 2011
Location: Alberta, Canada
Posts: 120
Default

But 6500k is very vague. I doesn't tell you how its producing that temperature. Just as par doesn't tell you the effectiveness for photosynthesis .
Deano85 is offline   Reply With Quote
Old 12-22-2013, 11:20 PM   #6
jeffkrol
Wannabe Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 1,732
Default

Quote:
Originally Posted by Deano85 View Post
From the beginning of time we were told to get optimum plant growth you need you use 6500k bulbs. As long as the plants gets enough from the blue and red spectrum what does it matter? Does anyone know of any experiment done with identical tanks one with warm and the other cool white bulbs?
there is no definable color temp for "best growth"..


http://inhabitat.com/indoor-vertical...h-less-energy/
Warm vs cool are mostly aesthetic considerations....
jeffkrol is offline   Reply With Quote
Old 12-22-2013, 11:44 PM   #7
Legot
Planted Member
 
Legot's Avatar
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: Gilbert, Arizona
Posts: 251
Default

I highly doubt there's much to do with increased growth, but for me It's definitely aesthetic. I really prefer 6x00k to any other straight color temperature. The more pure white just looks better to me (my ceiling lighting is even 5000k).

There also may be an observation by someone in the past between increased algae growth and lower K lights, but I've never read it.
__________________
People are too often merely stating an assumed truth from flawed observation.
Legot is offline   Reply With Quote
Old 12-22-2013, 11:55 PM   #8
MCHRKiller
Planted Tank Enthusiast
 
MCHRKiller's Avatar
 
PTrader: (40/100%)
Join Date: Jul 2008
Location: VA
Posts: 812
Default

I use 10000K on most of my tanks...looks better and less "green" than 6500K IMO. No noticeable difference between before when I did use lower K bulbs. I have always heard anything between 5000-10000K worked best for plants.
__________________

150G|100G|50G|20G|10G|10G

~Jenn
MCHRKiller is offline   Reply With Quote
Old 12-23-2013, 12:01 AM   #9
Raymond S.
Planted Tank Guru
 
Raymond S.'s Avatar
 
PTrader: (2/100%)
Join Date: Dec 2012
Location: Hot Springs Ar. 71901
Posts: 2,075
Default

All I know about this is that it confuses me. But why ? Because, for example...
The 460 and 660 nm range of spectrum is the aria of spectrum which plants use most.
A ZooMed Tropical sun @ 5500K has a little light showing that comes from every nm spectrum across the board.
Except the it does have a spike at the 450nm mark.
The Zoo Med Flora Grow is 5000K but has spikes in both ranges which plants use, but does put out less visible light than the Tropical.
The Ultra sun @6500K is brighter than either of the other but I can't find a chart on it.
Point is that I get much more algae/w the Ultra sun than either of the other two. It proves to me that it has more of what plants use.
On the other hand I do know a person who had a dual bulb shop light fixture on a 75 G tank for one year and then changed the bulbs to
6700K bulbs and got growth which he measured as being different on a day buy day growth rate chart. The 6700K was better.
So both that person and I tried different bulbs but from opposite ends of the range and found that the 6500/6700K grew better than
either the 5000K or the 10,000K. Now if it grows better or the same as the 3000K I don't know.
Raymond S. is online now   Reply With Quote
Old 12-23-2013, 12:05 AM   #10
Texan78
Planted Tank Enthusiast
 
Texan78's Avatar
 
PTrader: (0/0%)
Join Date: Nov 2013
Location: North Texas
Posts: 836
Default

Quote:
Originally Posted by Legot View Post
I highly doubt there's much to do with increased growth, but for me It's definitely aesthetic. I really prefer 6x00k to any other straight color temperature. The more pure white just looks better to me (my ceiling lighting is even 5000k).
+1 agreed... I prefer a more pure white than a warm white as well. IMO it is personal preference on how you want to view your plants and fish and what looks better to you.
Texan78 is offline   Reply With Quote
Old 12-23-2013, 12:07 AM   #11
xmas_one
Planted Tank Guru
 
PTrader: (17/100%)
Join Date: Feb 2010
Location: Long Beach, CA
Posts: 3,245
Default

Where's that quote when I need it, something something when we begin to obsess about numbers something something that's when we're doing bad science something something.
xmas_one is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 09:39 AM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright Planted Tank LLC 2012