Color Temp For Lights

[bordercollie05]

Does anyone know how big of a difference 5,000K vs. 6500K lights would be? I'd need two of the 5,000K or 4 of the 6500K to get the same lumens. Or maybe having two 6500K and one 5000K and staggering the lighting periods would be the way to go?

Also, how deep does the water need to be before you need more lumens/sq inch? (my tank is a 20H so its 17" tall)

Thanks for any advice!

Laura

 

[Mikaila31]

we normally go by watts per gallon, I have know idea about the lumens/square inch. But color temp. doesn't much at all to the plants, the big question is which lights do you like better?

 

[bordercollie05]

we normally go by watts per gallon, I have know idea about the lumens/square inch. But color temp. doesn't much at all to the plants, the big question is which lights do you like better?

I'm using lumens because the lights will be compact flourescent. 150 lumens/sq inch = ~3 wpg if using standard flourescents. I thought color temp mattered some, but I wasn't sure to what extent.

Laura

 

[raptorrex]

Does anyone know how big of a difference 5,000K vs. 6500K lights would be? I'd need two of the 5,000K or 4 of the 6500K to get the same lumens. Or maybe having two 6500K and one 5000K and staggering the lighting periods would be the way to go?

Also, how deep does the water need to be before you need more lumens/sq inch? (my tank is a 20H so its 17" tall)

Thanks for any advice!

Laura

i think you will find little difference between the two you mention, providing they are in the 4500-6000 range things should be OK.

 

[NoRp]

i came across something not to long ago about lumens it was a very good article. if you serch google or other places for 33000 lumens it should come up. i also think theres a good article someplace on kelvin or colour temp. sorry i couldnt give you the direct links but i guess u gotta do some of the reserch for yourself. its half the fun!

 

[aaronnorth]

6500k are often reccomended as they are not to pink or wbkue coloured, they produce a braod range of colours.

The 5000k will be more pinkish that's all but it wont be too bad.

 

[SuperColey1]

The height wont matter at all. Up to 2ft is the suggested height to think about but you have the same height as me.

If you are adding up to 3WPG of CF with reflectors please remember that the WPG rule is very basic and was calculated on T12. Think more that your lights will be equivalent to 1.5x or more the WPG rule due to their greater efficiency. Therefore 3WPG actual = 4.5WPG or more equivalent!!!!

Thats very high light with T5 or PC so be careful. Definately pressurised CO2, 10-20x filter lph and good dosing/maintenance regime.

Personally I wouldnt use 2 of the same bulb. I would use the 5000K for the photoperiod and a 6500K for a noon burst. You will still have plenty enough light in there to grow anything you want. I personally dont like PC anyway and moved on to T5HO linear very quickly. Much prefer to space my tubes out than be forced to have 2 so close together giving incredibly intense light to certain points. Its also damned hard to get good photos without having a top camera because it washes out the top third of the tank in certain places.

K - Just stay within the 4000-10000 range and buy what suits you eyes. In other words get a combo you like the effect of. The plants will glean what they want from anything within this range. Too much is made of the K rating. Its more of a human perception thing.

AC

 

[bordercollie05]

Thanks so much all for the input.

Norp: I think I have seen the article you are talking about, I did the research about lumens etc months ago and am just working from my notes now. I should go back and find those articles though, that would definitely help.

Supercoley: I was thinking 2ft was the minimum to worry about, thanks for confirming. I think I will use two different bulbs for a noon burst effect. Good suggestion.

boboboy and aaron: How far to you have to jump in K before you notice much difference? I was thinking these would be too close to notice much.

Thanks again!

Laura

Also, one more Q. If I do stagger the light periods do I add the WPG/Lumens during the lowest or highest light period to figure my lighting intensity. Or should I take the average to figure the light intensity?

 

[aaronnorth]

How far to you have to jump in K before you notice much difference? I was thinking these would be too close to notice much.

IMO <4000k for pinks, and for blue >11 000k

Also, one more Q. If I do stagger the light periods do I add the WPG/Lumens during the lowest or highest light period to figure my lighting intensity. Or should I take the average to figure the light intensity?

use 2 of the bulbs for 4 hours, then all 4 tubes for 2 hours, then back to 2 tubes for the remaining 4 hours.

 

[SuperColey1]

You will find that the 5000K has a slight pink tinge to it. most of the so called plant lights etc are 4000K-4500K.

There will be a huge difference betwen the 5000K and the 6500K just by looking directly at them when lit. The 6500K will appear to your eye as brighter and whiter.

In reality when you have them over the tank on their own a light in the 3000K range will give off a yellow/orange effect, 4500K pinkish, 6500K greenish and 10000K+towards blueish. Try to find a combo that when used together look natural to you.


I would judge the WPG as the 2 combined including the noon burst. The noon burst can be 2,3,4 etc. i.e. 3hrs 1 light,4hrs 2 lights, 3hrs 1 light. You chose the timings you want. I dont go in for high light, low light arguments with plants as I find that many high light plants can grow in what people would perceive as very low light.

Dont worry about your light intensity too much. People get carried with away with WPG and Lumens etc. Gauge your lights as needing 1-2WPG total of T8 or 1WPG of T5HO and then judge the plants results to figure out wether you need more or less. Dont confuse the answers the plants give you though. Lots of people see the plant die and assume they need more light when in fact it more often than not is the opposite that the plants dont have the nutrient required for the amount of light they already have.

AC