Lighting temperature question

[Hornet]

Ok so i know your meant to use lights between 6500 and 7000k for the best plant growth. My question is can 2 4000k tubes be used to make it 8000k (if thats not too much) or will it just be 4000k still?

[EvilLost]

no, they don't add up.

the 4000K number represents the color temperature, not "how much" light there is (that is the luminosity, or roughly, the wattage)

also, more is not better. you want to be in the 6500K range....10,000K (like for aquariums) is not going to give you "better" plants (in fact, it will give you somewhat worse)

[gex23]

As above, you can't 'add up' the K ratings to produce a different figure.

I've combined 4 x 6500k, 1 x 8000k and 1 x Gro-lux style T5 on my 65 gallon, and the overall look is pleasing to the eye.

While 6500k is the best 'all round' colour, combining different K ratings can improve the overall appearance of the greens / reds etc.

Anthony.

[Hornet]

Alright, cheers guys

[Pumilo]

I agree with what's been said, but you can use them until your new ones arrive. 4000K will generally grow plants but the color will be "off", looking kind of pinkish.

[Hornet]

the viv isnt even built yet so will just keep them for emergengy use. Once i'm ready to start on the build i'll be throwing quite a few q's out here for your guys